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9e0adb9b09
busybox/shell/hush.c
Denys Vlasenko 9e0adb9b09 hush: fix quoted "${notexist-}" expansion to not disappear 
function                                             old     new   delta
expand_one_var                                      2296    2311     +15

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2019-05-15 13:39:19 +02:00

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/* vi: set sw=4 ts=4: */
/*
* A prototype Bourne shell grammar parser.
* Intended to follow the original Thompson and Ritchie
* "small and simple is beautiful" philosophy, which
* incidentally is a good match to today's BusyBox.
*
* Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
* Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*
* Credits:
* The parser routines proper are all original material, first
* written Dec 2000 and Jan 2001 by Larry Doolittle. The
* execution engine, the builtins, and much of the underlying
* support has been adapted from busybox-0.49pre's lash, which is
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
* written by Erik Andersen <andersen@codepoet.org>. That, in turn,
* is based in part on ladsh.c, by Michael K. Johnson and Erik W.
* Troan, which they placed in the public domain. I don't know
* how much of the Johnson/Troan code has survived the repeated
* rewrites.
*
* Other credits:
* o_addchr derived from similar w_addchar function in glibc-2.2.
* parse_redirect, redirect_opt_num, and big chunks of main
* and many builtins derived from contributions by Erik Andersen.
* Miscellaneous bugfixes from Matt Kraai.
*
* There are two big (and related) architecture differences between
* this parser and the lash parser. One is that this version is
* actually designed from the ground up to understand nearly all
* of the Bourne grammar. The second, consequential change is that
* the parser and input reader have been turned inside out. Now,
* the parser is in control, and asks for input as needed. The old
* way had the input reader in control, and it asked for parsing to
* take place as needed. The new way makes it much easier to properly
* handle the recursion implicit in the various substitutions, especially
* across continuation lines.
*
* TODOs:
* grep for "TODO" and fix (some of them are easy)
* make complex ${var%...} constructs support optional
* make here documents optional
* special variables (done: PWD, PPID, RANDOM)
* follow IFS rules more precisely, including update semantics
* tilde expansion
* aliases
* "command" missing features:
* command -p CMD: run CMD using default $PATH
* (can use this to override standalone shell as well?)
* command BLTIN: disables special-ness (e.g. errors do not abort)
* command -V CMD1 CMD2 CMD3 (multiple args) (not in standard)
* builtins mandated by standards we don't support:
* [un]alias, fc:
* fc -l[nr] [BEG] [END]: list range of commands in history
* fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands
* fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP
*
* Bash compat TODO:
* redirection of stdout+stderr: &> and >&
* reserved words: function select
* advanced test: [[ ]]
* process substitution: <(list) and >(list)
* =~: regex operator
* let EXPR [EXPR...]
* Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
* If the last arg evaluates to 0, let returns 1; 0 otherwise.
* NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
* ((EXPR))
* The EXPR is evaluated according to ARITHMETIC EVALUATION.
* This is exactly equivalent to let "EXPR".
* $[EXPR]: synonym for $((EXPR))
* indirect expansion: ${!VAR}
* substring op on @: ${@:n:m}
*
* Won't do:
* Some builtins mandated by standards:
* newgrp [GRP]: not a builtin in bash but a suid binary
* which spawns a new shell with new group ID
*
* Status of [[ support:
* [[ args ]] are CMD_SINGLEWORD_NOGLOB:
* v='a b'; [[ $v = 'a b' ]]; echo 0:$?
* [[ /bin/n* ]]; echo 0:$?
* TODO:
* &&/|| are AND/OR ops, -a/-o are not
* quoting needs to be considered (-f is an operator, "-f" and ""-f are not; etc)
* = is glob match operator, not equality operator: STR = GLOB
* (in GLOB, quoting is significant on char-by-char basis: a*cd"*")
* == same as =
* add =~ regex match operator: STR =~ REGEX
*/
//config:config HUSH
//config: bool "hush (68 kb)"
//config: default y
//config: help
//config: hush is a small shell. It handles the normal flow control
//config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
//config: case/esac. Redirections, here documents, $((arithmetic))
//config: and functions are supported.
//config:
//config: It will compile and work on no-mmu systems.
//config:
//config: It does not handle select, aliases, tilde expansion,
//config: &>file and >&file redirection of stdout+stderr.
//config:
//config:config HUSH_BASH_COMPAT
//config: bool "bash-compatible extensions"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_BRACE_EXPANSION
//config: bool "Brace expansion"
//config: default y
//config: depends on HUSH_BASH_COMPAT
//config: help
//config: Enable {abc,def} extension.
//config:
//config:config HUSH_LINENO_VAR
//config: bool "$LINENO variable"
//config: default y
//config: depends on HUSH_BASH_COMPAT
//config:
//config:config HUSH_BASH_SOURCE_CURDIR
//config: bool "'source' and '.' builtins search current directory after $PATH"
//config: default n # do not encourage non-standard behavior
//config: depends on HUSH_BASH_COMPAT
//config: help
//config: This is not compliant with standards. Avoid if possible.
//config:
//config:config HUSH_INTERACTIVE
//config: bool "Interactive mode"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config: help
//config: Enable interactive mode (prompt and command editing).
//config: Without this, hush simply reads and executes commands
//config: from stdin just like a shell script from a file.
//config: No prompt, no PS1/PS2 magic shell variables.
//config:
//config:config HUSH_SAVEHISTORY
//config: bool "Save command history to .hush_history"
//config: default y
//config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
//config:
//config:config HUSH_JOB
//config: bool "Job control"
//config: default y
//config: depends on HUSH_INTERACTIVE
//config: help
//config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
//config: command (not entire shell), fg/bg builtins work. Without this option,
//config: "cmd &" still works by simply spawning a process and immediately
//config: prompting for next command (or executing next command in a script),
//config: but no separate process group is formed.
//config:
//config:config HUSH_TICK
//config: bool "Support command substitution"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config: help
//config: Enable `command` and $(command).
//config:
//config:config HUSH_IF
//config: bool "Support if/then/elif/else/fi"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_LOOPS
//config: bool "Support for, while and until loops"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_CASE
//config: bool "Support case ... esac statement"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config: help
//config: Enable case ... esac statement. +400 bytes.
//config:
//config:config HUSH_FUNCTIONS
//config: bool "Support funcname() { commands; } syntax"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config: help
//config: Enable support for shell functions. +800 bytes.
//config:
//config:config HUSH_LOCAL
//config: bool "local builtin"
//config: default y
//config: depends on HUSH_FUNCTIONS
//config: help
//config: Enable support for local variables in functions.
//config:
//config:config HUSH_RANDOM_SUPPORT
//config: bool "Pseudorandom generator and $RANDOM variable"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config: help
//config: Enable pseudorandom generator and dynamic variable "$RANDOM".
//config: Each read of "$RANDOM" will generate a new pseudorandom value.
//config:
//config:config HUSH_MODE_X
//config: bool "Support 'hush -x' option and 'set -x' command"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config: help
//config: This instructs hush to print commands before execution.
//config: Adds ~300 bytes.
//config:
//config:config HUSH_ECHO
//config: bool "echo builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_PRINTF
//config: bool "printf builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_TEST
//config: bool "test builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_HELP
//config: bool "help builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_EXPORT
//config: bool "export builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_EXPORT_N
//config: bool "Support 'export -n' option"
//config: default y
//config: depends on HUSH_EXPORT
//config: help
//config: export -n unexports variables. It is a bash extension.
//config:
//config:config HUSH_READONLY
//config: bool "readonly builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config: help
//config: Enable support for read-only variables.
//config:
//config:config HUSH_KILL
//config: bool "kill builtin (supports kill %jobspec)"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_WAIT
//config: bool "wait builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_COMMAND
//config: bool "command builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_TRAP
//config: bool "trap builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_TYPE
//config: bool "type builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_TIMES
//config: bool "times builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_READ
//config: bool "read builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_SET
//config: bool "set builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_UNSET
//config: bool "unset builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_ULIMIT
//config: bool "ulimit builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_UMASK
//config: bool "umask builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_GETOPTS
//config: bool "getopts builtin"
//config: default y
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//config:
//config:config HUSH_MEMLEAK
//config: bool "memleak builtin (debugging)"
//config: default n
//config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
//applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
// APPLET_ODDNAME:name main location suid_type help
//applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
//applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
//kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
//kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
//kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
//kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
/* -i (interactive) is also accepted,
* but does nothing, therefore not shown in help.
* NOMMU-specific options are not meant to be used by users,
* therefore we don't show them either.
*/
//usage:#define hush_trivial_usage
//usage: "[-enxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS] / -s [ARGS]]"
//usage:#define hush_full_usage "\n\n"
//usage: "Unix shell interpreter"
#if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
|| defined(__APPLE__) \
)
# include <malloc.h> /* for malloc_trim */
#endif
#include <glob.h>
/* #include <dmalloc.h> */
#if ENABLE_HUSH_CASE
# include <fnmatch.h>
#endif
#include <sys/times.h>
#include <sys/utsname.h> /* for setting $HOSTNAME */
#include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
#include "unicode.h"
#include "shell_common.h"
#include "math.h"
#include "match.h"
#if ENABLE_HUSH_RANDOM_SUPPORT
# include "random.h"
#else
# define CLEAR_RANDOM_T(rnd) ((void)0)
#endif
#ifndef O_CLOEXEC
# define O_CLOEXEC 0
#endif
#ifndef F_DUPFD_CLOEXEC
# define F_DUPFD_CLOEXEC F_DUPFD
#endif
#if ENABLE_FEATURE_SH_EMBEDDED_SCRIPTS && !(ENABLE_ASH || ENABLE_SH_IS_ASH || ENABLE_BASH_IS_ASH)
# include "embedded_scripts.h"
#else
# define NUM_SCRIPTS 0
#endif
/* So far, all bash compat is controlled by one config option */
/* Separate defines document which part of code implements what */
#define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
#define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
#define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
#define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
#define BASH_EPOCH_VARS ENABLE_HUSH_BASH_COMPAT
#define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
#define BASH_READ_D ENABLE_HUSH_BASH_COMPAT
/* Build knobs */
#define LEAK_HUNTING 0
#define BUILD_AS_NOMMU 0
/* Enable/disable sanity checks. Ok to enable in production,
* only adds a bit of bloat. Set to >1 to get non-production level verbosity.
* Keeping 1 for now even in released versions.
*/
#define HUSH_DEBUG 1
/* Slightly bigger (+200 bytes), but faster hush.
* So far it only enables a trick with counting SIGCHLDs and forks,
* which allows us to do fewer waitpid's.
* (we can detect a case where neither forks were done nor SIGCHLDs happened
* and therefore waitpid will return the same result as last time)
*/
#define ENABLE_HUSH_FAST 0
/* TODO: implement simplified code for users which do not need ${var%...} ops
* So far ${var%...} ops are always enabled:
*/
#define ENABLE_HUSH_DOLLAR_OPS 1
#if BUILD_AS_NOMMU
# undef BB_MMU
# undef USE_FOR_NOMMU
# undef USE_FOR_MMU
# define BB_MMU 0
# define USE_FOR_NOMMU(...) __VA_ARGS__
# define USE_FOR_MMU(...)
#endif
#include "NUM_APPLETS.h"
#if NUM_APPLETS == 1
/* STANDALONE does not make sense, and won't compile */
# undef CONFIG_FEATURE_SH_STANDALONE
# undef ENABLE_FEATURE_SH_STANDALONE
# undef IF_FEATURE_SH_STANDALONE
# undef IF_NOT_FEATURE_SH_STANDALONE
# define ENABLE_FEATURE_SH_STANDALONE 0
# define IF_FEATURE_SH_STANDALONE(...)
# define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
#endif
#if !ENABLE_HUSH_INTERACTIVE
# undef ENABLE_FEATURE_EDITING
# define ENABLE_FEATURE_EDITING 0
# undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
# define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
# undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
# define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
#endif
/* Do we support ANY keywords? */
#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
# define HAS_KEYWORDS 1
# define IF_HAS_KEYWORDS(...) __VA_ARGS__
# define IF_HAS_NO_KEYWORDS(...)
#else
# define HAS_KEYWORDS 0
# define IF_HAS_KEYWORDS(...)
# define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
#endif
/* If you comment out one of these below, it will be #defined later
* to perform debug printfs to stderr: */
#define debug_printf(...) do {} while (0)
/* Finer-grained debug switches */
#define debug_printf_parse(...) do {} while (0)
#define debug_printf_heredoc(...) do {} while (0)
#define debug_print_tree(a, b) do {} while (0)
#define debug_printf_exec(...) do {} while (0)
#define debug_printf_env(...) do {} while (0)
#define debug_printf_jobs(...) do {} while (0)
#define debug_printf_expand(...) do {} while (0)
#define debug_printf_varexp(...) do {} while (0)
#define debug_printf_glob(...) do {} while (0)
#define debug_printf_redir(...) do {} while (0)
#define debug_printf_list(...) do {} while (0)
#define debug_printf_subst(...) do {} while (0)
#define debug_printf_prompt(...) do {} while (0)
#define debug_printf_clean(...) do {} while (0)
#define ERR_PTR ((void*)(long)1)
#define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
#define _SPECIAL_VARS_STR "_*@$!?#"
#define SPECIAL_VARS_STR ("_*@$!?#" + 1)
#define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
#if BASH_PATTERN_SUBST
/* Support / and // replace ops */
/* Note that // is stored as \ in "encoded" string representation */
# define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
# define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
# define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
#else
# define VAR_ENCODED_SUBST_OPS "%#:-=+?"
# define VAR_SUBST_OPS "%#:-=+?"
# define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
#endif
#define SPECIAL_VAR_SYMBOL_STR "\3"
#define SPECIAL_VAR_SYMBOL 3
/* The "variable" with name "\1" emits string "\3". Testcase: "echo ^C" */
#define SPECIAL_VAR_QUOTED_SVS 1
struct variable;
static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
/* This supports saving pointers malloced in vfork child,
* to be freed in the parent.
*/
#if !BB_MMU
typedef struct nommu_save_t {
struct variable *old_vars;
char **argv;
char **argv_from_re_execing;
} nommu_save_t;
#endif
enum {
RES_NONE = 0,
#if ENABLE_HUSH_IF
RES_IF ,
RES_THEN ,
RES_ELIF ,
RES_ELSE ,
RES_FI ,
#endif
#if ENABLE_HUSH_LOOPS
RES_FOR ,
RES_WHILE ,
RES_UNTIL ,
RES_DO ,
RES_DONE ,
#endif
#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
RES_IN ,
#endif
#if ENABLE_HUSH_CASE
RES_CASE ,
/* three pseudo-keywords support contrived "case" syntax: */
RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
RES_MATCH , /* "word)" */
RES_CASE_BODY, /* "this command is inside CASE" */
RES_ESAC ,
#endif
RES_XXXX ,
RES_SNTX
};
typedef struct o_string {
char *data;
int length; /* position where data is appended */
int maxlen;
int o_expflags;
/* At least some part of the string was inside '' or "",
* possibly empty one: word"", wo''rd etc. */
smallint has_quoted_part;
smallint has_empty_slot;
smallint ended_in_ifs;
} o_string;
enum {
EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
EXP_FLAG_GLOB = 0x2,
/* Protect newly added chars against globbing
* by prepending \ to *, ?, [, \ */
EXP_FLAG_ESC_GLOB_CHARS = 0x1,
};
/* Used for initialization: o_string foo = NULL_O_STRING; */
#define NULL_O_STRING { NULL }
#ifndef debug_printf_parse
static const char *const assignment_flag[] = {
"MAYBE_ASSIGNMENT",
"DEFINITELY_ASSIGNMENT",
"NOT_ASSIGNMENT",
"WORD_IS_KEYWORD",
};
#endif
/* We almost can use standard FILE api, but we need an ability to move
* its fd when redirects coincide with it. No api exists for that
* (RFE for it at https://sourceware.org/bugzilla/show_bug.cgi?id=21902).
* HFILE is our internal alternative. Only supports reading.
* Since we now can, we incorporate linked list of all opened HFILEs
* into the struct (used to be a separate mini-list).
*/
typedef struct HFILE {
char *cur;
char *end;
struct HFILE *next_hfile;
int is_stdin;
int fd;
char buf[1024];
} HFILE;
typedef struct in_str {
const char *p;
int peek_buf[2];
int last_char;
HFILE *file;
} in_str;
/* The descrip member of this structure is only used to make
* debugging output pretty */
static const struct {
int mode;
signed char default_fd;
char descrip[3];
} redir_table[] = {
{ O_RDONLY, 0, "<" },
{ O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
{ O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
{ O_CREAT|O_RDWR, 1, "<>" },
{ O_RDONLY, 0, "<<" },
/* Should not be needed. Bogus default_fd helps in debugging */
/* { O_RDONLY, 77, "<<" }, */
};
struct redir_struct {
struct redir_struct *next;
char *rd_filename; /* filename */
int rd_fd; /* fd to redirect */
/* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
int rd_dup;
smallint rd_type; /* (enum redir_type) */
/* note: for heredocs, rd_filename contains heredoc delimiter,
* and subsequently heredoc itself; and rd_dup is a bitmask:
* bit 0: do we need to trim leading tabs?
* bit 1: is heredoc quoted (<<'delim' syntax) ?
*/
};
typedef enum redir_type {
REDIRECT_INPUT = 0,
REDIRECT_OVERWRITE = 1,
REDIRECT_APPEND = 2,
REDIRECT_IO = 3,
REDIRECT_HEREDOC = 4,
REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
REDIRFD_CLOSE = -3,
REDIRFD_SYNTAX_ERR = -2,
REDIRFD_TO_FILE = -1,
/* otherwise, rd_fd is redirected to rd_dup */
HEREDOC_SKIPTABS = 1,
HEREDOC_QUOTED = 2,
} redir_type;
struct command {
pid_t pid; /* 0 if exited */
unsigned assignment_cnt; /* how many argv[i] are assignments? */
#if ENABLE_HUSH_LINENO_VAR
unsigned lineno;
#endif
smallint cmd_type; /* CMD_xxx */
#define CMD_NORMAL 0
#define CMD_SUBSHELL 1
#if BASH_TEST2 || ENABLE_HUSH_LOCAL || ENABLE_HUSH_EXPORT || ENABLE_HUSH_READONLY
/* used for "[[ EXPR ]]", and to prevent word splitting and globbing in
* "export v=t*"
*/
# define CMD_SINGLEWORD_NOGLOB 2
#endif
#if ENABLE_HUSH_FUNCTIONS
# define CMD_FUNCDEF 3
#endif
smalluint cmd_exitcode;
/* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
struct pipe *group;
#if !BB_MMU
char *group_as_string;
#endif
#if ENABLE_HUSH_FUNCTIONS
struct function *child_func;
/* This field is used to prevent a bug here:
* while...do f1() {a;}; f1; f1() {b;}; f1; done
* When we execute "f1() {a;}" cmd, we create new function and clear
* cmd->group, cmd->group_as_string, cmd->argv[0].
* When we execute "f1() {b;}", we notice that f1 exists,
* and that its "parent cmd" struct is still "alive",
* we put those fields back into cmd->xxx
* (struct function has ->parent_cmd ptr to facilitate that).
* When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
* Without this trick, loop would execute a;b;b;b;...
* instead of correct sequence a;b;a;b;...
* When command is freed, it severs the link
* (sets ->child_func->parent_cmd to NULL).
*/
#endif
char **argv; /* command name and arguments */
/* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
* and on execution these are substituted with their values.
* Substitution can make _several_ words out of one argv[n]!
* Example: argv[0]=='.^C*^C.' here: echo .$*.
* References of the form ^C`cmd arg^C are `cmd arg` substitutions.
*/
struct redir_struct *redirects; /* I/O redirections */
};
/* Is there anything in this command at all? */
#define IS_NULL_CMD(cmd) \
(!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
struct pipe {
struct pipe *next;
int num_cmds; /* total number of commands in pipe */
int alive_cmds; /* number of commands running (not exited) */
int stopped_cmds; /* number of commands alive, but stopped */
#if ENABLE_HUSH_JOB
unsigned jobid; /* job number */
pid_t pgrp; /* process group ID for the job */
char *cmdtext; /* name of job */
#endif
struct command *cmds; /* array of commands in pipe */
smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
};
typedef enum pipe_style {
PIPE_SEQ = 0,
PIPE_AND = 1,
PIPE_OR = 2,
PIPE_BG = 3,
} pipe_style;
/* Is there anything in this pipe at all? */
#define IS_NULL_PIPE(pi) \
((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
/* This holds pointers to the various results of parsing */
struct parse_context {
/* linked list of pipes */
struct pipe *list_head;
/* last pipe (being constructed right now) */
struct pipe *pipe;
/* last command in pipe (being constructed right now) */
struct command *command;
/* last redirect in command->redirects list */
struct redir_struct *pending_redirect;
o_string word;
#if !BB_MMU
o_string as_string;
#endif
smallint is_assignment; /* 0:maybe, 1:yes, 2:no, 3:keyword */
#if HAS_KEYWORDS
smallint ctx_res_w;
smallint ctx_inverted; /* "! cmd | cmd" */
#if ENABLE_HUSH_CASE
smallint ctx_dsemicolon; /* ";;" seen */
#endif
/* bitmask of FLAG_xxx, for figuring out valid reserved words */
int old_flag;
/* group we are enclosed in:
* example: "if pipe1; pipe2; then pipe3; fi"
* when we see "if" or "then", we malloc and copy current context,
* and make ->stack point to it. then we parse pipeN.
* when closing "then" / fi" / whatever is found,
* we move list_head into ->stack->command->group,
* copy ->stack into current context, and delete ->stack.
* (parsing of { list } and ( list ) doesn't use this method)
*/
struct parse_context *stack;
#endif
};
enum {
MAYBE_ASSIGNMENT = 0,
DEFINITELY_ASSIGNMENT = 1,
NOT_ASSIGNMENT = 2,
/* Not an assignment, but next word may be: "if v=xyz cmd;" */
WORD_IS_KEYWORD = 3,
};
/* On program start, environ points to initial environment.
* putenv adds new pointers into it, unsetenv removes them.
* Neither of these (de)allocates the strings.
* setenv allocates new strings in malloc space and does putenv,
* and thus setenv is unusable (leaky) for shell's purposes */
#define setenv(...) setenv_is_leaky_dont_use()
struct variable {
struct variable *next;
char *varstr; /* points to "name=" portion */
int max_len; /* if > 0, name is part of initial env; else name is malloced */
uint16_t var_nest_level;
smallint flg_export; /* putenv should be done on this var */
smallint flg_read_only;
};
enum {
BC_BREAK = 1,
BC_CONTINUE = 2,
};
#if ENABLE_HUSH_FUNCTIONS
struct function {
struct function *next;
char *name;
struct command *parent_cmd;
struct pipe *body;
# if !BB_MMU
char *body_as_string;
# endif
};
#endif
/* set -/+o OPT support. (TODO: make it optional)
* bash supports the following opts:
* allexport off
* braceexpand on
* emacs on
* errexit off
* errtrace off
* functrace off
* hashall on
* histexpand off
* history on
* ignoreeof off
* interactive-comments on
* keyword off
* monitor on
* noclobber off
* noexec off
* noglob off
* nolog off
* notify off
* nounset off
* onecmd off
* physical off
* pipefail off
* posix off
* privileged off
* verbose off
* vi off
* xtrace off
*/
static const char o_opt_strings[] ALIGN1 =
"pipefail\0"
"noexec\0"
"errexit\0"
#if ENABLE_HUSH_MODE_X
"xtrace\0"
#endif
;
enum {
OPT_O_PIPEFAIL,
OPT_O_NOEXEC,
OPT_O_ERREXIT,
#if ENABLE_HUSH_MODE_X
OPT_O_XTRACE,
#endif
NUM_OPT_O
};
/* "Globals" within this file */
/* Sorted roughly by size (smaller offsets == smaller code) */
struct globals {
/* interactive_fd != 0 means we are an interactive shell.
* If we are, then saved_tty_pgrp can also be != 0, meaning
* that controlling tty is available. With saved_tty_pgrp == 0,
* job control still works, but terminal signals
* (^C, ^Z, ^Y, ^\) won't work at all, and background
* process groups can only be created with "cmd &".
* With saved_tty_pgrp != 0, hush will use tcsetpgrp()
* to give tty to the foreground process group,
* and will take it back when the group is stopped (^Z)
* or killed (^C).
*/
#if ENABLE_HUSH_INTERACTIVE
/* 'interactive_fd' is a fd# open to ctty, if we have one
* _AND_ if we decided to act interactively */
int interactive_fd;
const char *PS1;
IF_FEATURE_EDITING_FANCY_PROMPT(const char *PS2;)
# define G_interactive_fd (G.interactive_fd)
#else
# define G_interactive_fd 0
#endif
#if ENABLE_FEATURE_EDITING
line_input_t *line_input_state;
#endif
pid_t root_pid;
pid_t root_ppid;
pid_t last_bg_pid;
#if ENABLE_HUSH_RANDOM_SUPPORT
random_t random_gen;
#endif
#if ENABLE_HUSH_JOB
int run_list_level;
unsigned last_jobid;
pid_t saved_tty_pgrp;
struct pipe *job_list;
# define G_saved_tty_pgrp (G.saved_tty_pgrp)
#else
# define G_saved_tty_pgrp 0
#endif
/* How deeply are we in context where "set -e" is ignored */
int errexit_depth;
/* "set -e" rules (do we follow them correctly?):
* Exit if pipe, list, or compound command exits with a non-zero status.
* Shell does not exit if failed command is part of condition in
* if/while, part of && or || list except the last command, any command
* in a pipe but the last, or if the command's return value is being
* inverted with !. If a compound command other than a subshell returns a
* non-zero status because a command failed while -e was being ignored, the
* shell does not exit. A trap on ERR, if set, is executed before the shell
* exits [ERR is a bashism].
*
* If a compound command or function executes in a context where -e is
* ignored, none of the commands executed within are affected by the -e
* setting. If a compound command or function sets -e while executing in a
* context where -e is ignored, that setting does not have any effect until
* the compound command or the command containing the function call completes.
*/
char o_opt[NUM_OPT_O];
#if ENABLE_HUSH_MODE_X
# define G_x_mode (G.o_opt[OPT_O_XTRACE])
#else
# define G_x_mode 0
#endif
#if ENABLE_HUSH_INTERACTIVE
smallint promptmode; /* 0: PS1, 1: PS2 */
#endif
smallint flag_SIGINT;
#if ENABLE_HUSH_LOOPS
smallint flag_break_continue;
#endif
#if ENABLE_HUSH_FUNCTIONS
/* 0: outside of a function (or sourced file)
* -1: inside of a function, ok to use return builtin
* 1: return is invoked, skip all till end of func
*/
smallint flag_return_in_progress;
# define G_flag_return_in_progress (G.flag_return_in_progress)
#else
# define G_flag_return_in_progress 0
#endif
smallint exiting; /* used to prevent EXIT trap recursion */
/* These support $? */
smalluint last_exitcode;
smalluint expand_exitcode;
smalluint last_bg_pid_exitcode;
#if ENABLE_HUSH_SET
/* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
smalluint global_args_malloced;
# define G_global_args_malloced (G.global_args_malloced)
#else
# define G_global_args_malloced 0
#endif
#if ENABLE_HUSH_BASH_COMPAT
int dead_job_exitcode; /* for "wait -n" */
#endif
/* how many non-NULL argv's we have. NB: $# + 1 */
int global_argc;
char **global_argv;
#if !BB_MMU
char *argv0_for_re_execing;
#endif
#if ENABLE_HUSH_LOOPS
unsigned depth_break_continue;
unsigned depth_of_loop;
#endif
#if ENABLE_HUSH_GETOPTS
unsigned getopt_count;
#endif
const char *ifs;
char *ifs_whitespace; /* = G.ifs or malloced */
const char *cwd;
struct variable *top_var;
char **expanded_assignments;
struct variable **shadowed_vars_pp;
unsigned var_nest_level;
#if ENABLE_HUSH_FUNCTIONS
# if ENABLE_HUSH_LOCAL
unsigned func_nest_level; /* solely to prevent "local v" in non-functions */
# endif
struct function *top_func;
#endif
/* Signal and trap handling */
#if ENABLE_HUSH_FAST
unsigned count_SIGCHLD;
unsigned handled_SIGCHLD;
smallint we_have_children;
#endif
#if ENABLE_HUSH_LINENO_VAR
unsigned lineno;
char *lineno_var;
#endif
HFILE *HFILE_list;
/* Which signals have non-DFL handler (even with no traps set)?
* Set at the start to:
* (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
* SPECIAL_INTERACTIVE_SIGS are cleared after fork.
* The rest is cleared right before execv syscalls.
* Other than these two times, never modified.
*/
unsigned special_sig_mask;
#if ENABLE_HUSH_JOB
unsigned fatal_sig_mask;
# define G_fatal_sig_mask (G.fatal_sig_mask)
#else
# define G_fatal_sig_mask 0
#endif
#if ENABLE_HUSH_TRAP
char **traps; /* char *traps[NSIG] */
# define G_traps G.traps
#else
# define G_traps ((char**)NULL)
#endif
sigset_t pending_set;
#if ENABLE_HUSH_MEMLEAK
unsigned long memleak_value;
#endif
#if ENABLE_HUSH_MODE_X
unsigned x_mode_depth;
/* "set -x" output should not be redirectable with subsequent 2>FILE.
* We dup fd#2 to x_mode_fd when "set -x" is executed, and use it
* for all subsequent output.
*/
int x_mode_fd;
o_string x_mode_buf;
#endif
#if HUSH_DEBUG >= 2
int debug_indent;
#endif
struct sigaction sa;
#if BASH_EPOCH_VARS
char epoch_buf[sizeof("%lu.nnnnnn") + sizeof(long)*3];
#endif
#if ENABLE_FEATURE_EDITING
char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
#endif
};
#define G (*ptr_to_globals)
/* Not #defining name to G.name - this quickly gets unwieldy
* (too many defines). Also, I actually prefer to see when a variable
* is global, thus "G." prefix is a useful hint */
#define INIT_G() do { \
SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
/* memset(&G.sa, 0, sizeof(G.sa)); */ \
sigfillset(&G.sa.sa_mask); \
G.sa.sa_flags = SA_RESTART; \
} while (0)
/* Function prototypes for builtins */
static int builtin_cd(char **argv) FAST_FUNC;
#if ENABLE_HUSH_ECHO
static int builtin_echo(char **argv) FAST_FUNC;
#endif
static int builtin_eval(char **argv) FAST_FUNC;
static int builtin_exec(char **argv) FAST_FUNC;
static int builtin_exit(char **argv) FAST_FUNC;
#if ENABLE_HUSH_EXPORT
static int builtin_export(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_READONLY
static int builtin_readonly(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_JOB
static int builtin_fg_bg(char **argv) FAST_FUNC;
static int builtin_jobs(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_GETOPTS
static int builtin_getopts(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_HELP
static int builtin_help(char **argv) FAST_FUNC;
#endif
#if MAX_HISTORY && ENABLE_FEATURE_EDITING
static int builtin_history(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_LOCAL
static int builtin_local(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_MEMLEAK
static int builtin_memleak(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_PRINTF
static int builtin_printf(char **argv) FAST_FUNC;
#endif
static int builtin_pwd(char **argv) FAST_FUNC;
#if ENABLE_HUSH_READ
static int builtin_read(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_SET
static int builtin_set(char **argv) FAST_FUNC;
#endif
static int builtin_shift(char **argv) FAST_FUNC;
static int builtin_source(char **argv) FAST_FUNC;
#if ENABLE_HUSH_TEST || BASH_TEST2
static int builtin_test(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_TRAP
static int builtin_trap(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_TYPE
static int builtin_type(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_TIMES
static int builtin_times(char **argv) FAST_FUNC;
#endif
static int builtin_true(char **argv) FAST_FUNC;
#if ENABLE_HUSH_UMASK
static int builtin_umask(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_UNSET
static int builtin_unset(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_KILL
static int builtin_kill(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_WAIT
static int builtin_wait(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_LOOPS
static int builtin_break(char **argv) FAST_FUNC;
static int builtin_continue(char **argv) FAST_FUNC;
#endif
#if ENABLE_HUSH_FUNCTIONS
static int builtin_return(char **argv) FAST_FUNC;
#endif
/* Table of built-in functions. They can be forked or not, depending on
* context: within pipes, they fork. As simple commands, they do not.
* When used in non-forking context, they can change global variables
* in the parent shell process. If forked, of course they cannot.
* For example, 'unset foo | whatever' will parse and run, but foo will
* still be set at the end. */
struct built_in_command {
const char *b_cmd;
int (*b_function)(char **argv) FAST_FUNC;
#if ENABLE_HUSH_HELP
const char *b_descr;
# define BLTIN(cmd, func, help) { cmd, func, help }
#else
# define BLTIN(cmd, func, help) { cmd, func }
#endif
};
static const struct built_in_command bltins1[] = {
BLTIN("." , builtin_source , "Run commands in file"),
BLTIN(":" , builtin_true , NULL),
#if ENABLE_HUSH_JOB
BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
#endif
#if ENABLE_HUSH_LOOPS
BLTIN("break" , builtin_break , "Exit loop"),
#endif
BLTIN("cd" , builtin_cd , "Change directory"),
#if ENABLE_HUSH_LOOPS
BLTIN("continue" , builtin_continue, "Start new loop iteration"),
#endif
BLTIN("eval" , builtin_eval , "Construct and run shell command"),
BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
BLTIN("exit" , builtin_exit , NULL),
#if ENABLE_HUSH_EXPORT
BLTIN("export" , builtin_export , "Set environment variables"),
#endif
#if ENABLE_HUSH_JOB
BLTIN("fg" , builtin_fg_bg , "Bring job to foreground"),
#endif
#if ENABLE_HUSH_GETOPTS
BLTIN("getopts" , builtin_getopts , NULL),
#endif
#if ENABLE_HUSH_HELP
BLTIN("help" , builtin_help , NULL),
#endif
#if MAX_HISTORY && ENABLE_FEATURE_EDITING
BLTIN("history" , builtin_history , "Show history"),
#endif
#if ENABLE_HUSH_JOB
BLTIN("jobs" , builtin_jobs , "List jobs"),
#endif
#if ENABLE_HUSH_KILL
BLTIN("kill" , builtin_kill , "Send signals to processes"),
#endif
#if ENABLE_HUSH_LOCAL
BLTIN("local" , builtin_local , "Set local variables"),
#endif
#if ENABLE_HUSH_MEMLEAK
BLTIN("memleak" , builtin_memleak , NULL),
#endif
#if ENABLE_HUSH_READ
BLTIN("read" , builtin_read , "Input into variable"),
#endif
#if ENABLE_HUSH_READONLY
BLTIN("readonly" , builtin_readonly, "Make variables read-only"),
#endif
#if ENABLE_HUSH_FUNCTIONS
BLTIN("return" , builtin_return , "Return from function"),
#endif
#if ENABLE_HUSH_SET
BLTIN("set" , builtin_set , "Set positional parameters"),
#endif
BLTIN("shift" , builtin_shift , "Shift positional parameters"),
#if BASH_SOURCE
BLTIN("source" , builtin_source , NULL),
#endif
#if ENABLE_HUSH_TIMES
BLTIN("times" , builtin_times , NULL),
#endif
#if ENABLE_HUSH_TRAP
BLTIN("trap" , builtin_trap , "Trap signals"),
#endif
BLTIN("true" , builtin_true , NULL),
#if ENABLE_HUSH_TYPE
BLTIN("type" , builtin_type , "Show command type"),
#endif
#if ENABLE_HUSH_ULIMIT
BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
#endif
#if ENABLE_HUSH_UMASK
BLTIN("umask" , builtin_umask , "Set file creation mask"),
#endif
#if ENABLE_HUSH_UNSET
BLTIN("unset" , builtin_unset , "Unset variables"),
#endif
#if ENABLE_HUSH_WAIT
BLTIN("wait" , builtin_wait , "Wait for process to finish"),
#endif
};
/* These builtins won't be used if we are on NOMMU and need to re-exec
* (it's cheaper to run an external program in this case):
*/
static const struct built_in_command bltins2[] = {
#if ENABLE_HUSH_TEST
BLTIN("[" , builtin_test , NULL),
#endif
#if BASH_TEST2
BLTIN("[[" , builtin_test , NULL),
#endif
#if ENABLE_HUSH_ECHO
BLTIN("echo" , builtin_echo , NULL),
#endif
#if ENABLE_HUSH_PRINTF
BLTIN("printf" , builtin_printf , NULL),
#endif
BLTIN("pwd" , builtin_pwd , NULL),
#if ENABLE_HUSH_TEST
BLTIN("test" , builtin_test , NULL),
#endif
};
/* Debug printouts.
*/
#if HUSH_DEBUG >= 2
/* prevent disasters with G.debug_indent < 0 */
# define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
# define debug_enter() (G.debug_indent++)
# define debug_leave() (G.debug_indent--)
#else
# define indent() ((void)0)
# define debug_enter() ((void)0)
# define debug_leave() ((void)0)
#endif
#ifndef debug_printf
# define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_parse
# define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_heredoc
# define debug_printf_heredoc(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_exec
#define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_env
# define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_jobs
# define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
# define DEBUG_JOBS 1
#else
# define DEBUG_JOBS 0
#endif
#ifndef debug_printf_expand
# define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
# define DEBUG_EXPAND 1
#else
# define DEBUG_EXPAND 0
#endif
#ifndef debug_printf_varexp
# define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_glob
# define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
# define DEBUG_GLOB 1
#else
# define DEBUG_GLOB 0
#endif
#ifndef debug_printf_redir
# define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_list
# define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_subst
# define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_prompt
# define debug_printf_prompt(...) (indent(), fdprintf(2, __VA_ARGS__))
#endif
#ifndef debug_printf_clean
# define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
# define DEBUG_CLEAN 1
#else
# define DEBUG_CLEAN 0
#endif
#if DEBUG_EXPAND
static void debug_print_strings(const char *prefix, char **vv)
{
indent();
fdprintf(2, "%s:\n", prefix);
while (*vv)
fdprintf(2, " '%s'\n", *vv++);
}
#else
# define debug_print_strings(prefix, vv) ((void)0)
#endif
/* Leak hunting. Use hush_leaktool.sh for post-processing.
*/
#if LEAK_HUNTING
static void *xxmalloc(int lineno, size_t size)
{
void *ptr = xmalloc((size + 0xff) & ~0xff);
fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
return ptr;
}
static void *xxrealloc(int lineno, void *ptr, size_t size)
{
ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
return ptr;
}
static char *xxstrdup(int lineno, const char *str)
{
char *ptr = xstrdup(str);
fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
return ptr;
}
static void xxfree(void *ptr)
{
fdprintf(2, "free %p\n", ptr);
free(ptr);
}
# define xmalloc(s) xxmalloc(__LINE__, s)
# define xrealloc(p, s) xxrealloc(__LINE__, p, s)
# define xstrdup(s) xxstrdup(__LINE__, s)
# define free(p) xxfree(p)
#endif
/* Syntax and runtime errors. They always abort scripts.
* In interactive use they usually discard unparsed and/or unexecuted commands
* and return to the prompt.
* HUSH_DEBUG >= 2 prints line number in this file where it was detected.
*/
#if HUSH_DEBUG < 2
# define msg_and_die_if_script(lineno, ...) msg_and_die_if_script(__VA_ARGS__)
# define syntax_error(lineno, msg) syntax_error(msg)
# define syntax_error_at(lineno, msg) syntax_error_at(msg)
# define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
# define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
# define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
#endif
static void die_if_script(void)
{
if (!G_interactive_fd) {
if (G.last_exitcode) /* sometines it's 2, not 1 (bash compat) */
xfunc_error_retval = G.last_exitcode;
xfunc_die();
}
}
static void msg_and_die_if_script(unsigned lineno, const char *fmt, ...)
{
va_list p;
#if HUSH_DEBUG >= 2
bb_error_msg("hush.c:%u", lineno);
#endif
va_start(p, fmt);
bb_verror_msg(fmt, p, NULL);
va_end(p);
die_if_script();
}
static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
{
if (msg)
bb_error_msg("syntax error: %s", msg);
else
bb_error_msg("syntax error");
die_if_script();
}
static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
{
bb_error_msg("syntax error at '%s'", msg);
die_if_script();
}
static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
{
bb_error_msg("syntax error: unterminated %s", s);
//? source4.tests fails: in bash, echo ${^} in script does not terminate the script
// die_if_script();
}
static void syntax_error_unterm_ch(unsigned lineno, char ch)
{
char msg[2] = { ch, '\0' };
syntax_error_unterm_str(lineno, msg);
}
static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
{
char msg[2];
msg[0] = ch;
msg[1] = '\0';
#if HUSH_DEBUG >= 2
bb_error_msg("hush.c:%u", lineno);
#endif
bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
die_if_script();
}
#if HUSH_DEBUG < 2
# undef msg_and_die_if_script
# undef syntax_error
# undef syntax_error_at
# undef syntax_error_unterm_ch
# undef syntax_error_unterm_str
# undef syntax_error_unexpected_ch
#else
# define msg_and_die_if_script(...) msg_and_die_if_script(__LINE__, __VA_ARGS__)
# define syntax_error(msg) syntax_error(__LINE__, msg)
# define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
# define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
# define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
# define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
#endif
#if ENABLE_HUSH_INTERACTIVE && ENABLE_FEATURE_EDITING_FANCY_PROMPT
static void cmdedit_update_prompt(void);
#else
# define cmdedit_update_prompt() ((void)0)
#endif
/* Utility functions
*/
/* Replace each \x with x in place, return ptr past NUL. */
static char *unbackslash(char *src)
{
char *dst = src = strchrnul(src, '\\');
while (1) {
if (*src == '\\') {
src++;
if (*src != '\0') {
/* \x -> x */
*dst++ = *src++;
continue;
}
/* else: "\<nul>". Do not delete this backslash.
* Testcase: eval 'echo ok\'
*/
*dst++ = '\\';
/* fallthrough */
}
if ((*dst++ = *src++) == '\0')
break;
}
return dst;
}
static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
{
int i;
unsigned count1;
unsigned count2;
char **v;
v = strings;
count1 = 0;
if (v) {
while (*v) {
count1++;
v++;
}
}
count2 = 0;
v = add;
while (*v) {
count2++;
v++;
}
v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
v[count1 + count2] = NULL;
i = count2;
while (--i >= 0)
v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
return v;
}
#if LEAK_HUNTING
static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
{
char **ptr = add_strings_to_strings(strings, add, need_to_dup);
fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
return ptr;
}
#define add_strings_to_strings(strings, add, need_to_dup) \
xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
#endif
/* Note: takes ownership of "add" ptr (it is not strdup'ed) */
static char **add_string_to_strings(char **strings, char *add)
{
char *v[2];
v[0] = add;
v[1] = NULL;
return add_strings_to_strings(strings, v, /*dup:*/ 0);
}
#if LEAK_HUNTING
static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
{
char **ptr = add_string_to_strings(strings, add);
fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
return ptr;
}
#define add_string_to_strings(strings, add) \
xx_add_string_to_strings(__LINE__, strings, add)
#endif
static void free_strings(char **strings)
{
char **v;
if (!strings)
return;
v = strings;
while (*v) {
free(*v);
v++;
}
free(strings);
}
static int dup_CLOEXEC(int fd, int avoid_fd)
{
int newfd;
repeat:
newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
if (newfd >= 0) {
if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
fcntl(newfd, F_SETFD, FD_CLOEXEC);
} else { /* newfd < 0 */
if (errno == EBUSY)
goto repeat;
if (errno == EINTR)
goto repeat;
}
return newfd;
}
static int xdup_CLOEXEC_and_close(int fd, int avoid_fd)
{
int newfd;
repeat:
newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
if (newfd < 0) {
if (errno == EBUSY)
goto repeat;
if (errno == EINTR)
goto repeat;
/* fd was not open? */
if (errno == EBADF)
return fd;
xfunc_die();
}
if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
fcntl(newfd, F_SETFD, FD_CLOEXEC);
close(fd);
return newfd;
}
/* Manipulating HFILEs */
static HFILE *hfopen(const char *name)
{
HFILE *fp;
int fd;
fd = STDIN_FILENO;
if (name) {
fd = open(name, O_RDONLY | O_CLOEXEC);
if (fd < 0)
return NULL;
if (O_CLOEXEC == 0) /* ancient libc */
close_on_exec_on(fd);
}
fp = xmalloc(sizeof(*fp));
fp->is_stdin = (name == NULL);
fp->fd = fd;
fp->cur = fp->end = fp->buf;
fp->next_hfile = G.HFILE_list;
G.HFILE_list = fp;
return fp;
}
static void hfclose(HFILE *fp)
{
HFILE **pp = &G.HFILE_list;
while (*pp) {
HFILE *cur = *pp;
if (cur == fp) {
*pp = cur->next_hfile;
break;
}
pp = &cur->next_hfile;
}
if (fp->fd >= 0)
close(fp->fd);
free(fp);
}
static int refill_HFILE_and_getc(HFILE *fp)
{
int n;
if (fp->fd < 0) {
/* Already saw EOF */
return EOF;
}
/* Try to buffer more input */
fp->cur = fp->buf;
n = safe_read(fp->fd, fp->buf, sizeof(fp->buf));
if (n < 0) {
bb_perror_msg("read error");
n = 0;
}
fp->end = fp->buf + n;
if (n == 0) {
/* EOF/error */
close(fp->fd);
fp->fd = -1;
return EOF;
}
return (unsigned char)(*fp->cur++);
}
/* Inlined for common case of non-empty buffer.
*/
static ALWAYS_INLINE int hfgetc(HFILE *fp)
{
if (fp->cur < fp->end)
return (unsigned char)(*fp->cur++);
/* Buffer empty */
return refill_HFILE_and_getc(fp);
}
static int move_HFILEs_on_redirect(int fd, int avoid_fd)
{
HFILE *fl = G.HFILE_list;
while (fl) {
if (fd == fl->fd) {
/* We use it only on script files, they are all CLOEXEC */
fl->fd = xdup_CLOEXEC_and_close(fd, avoid_fd);
debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
return 1; /* "found and moved" */
}
fl = fl->next_hfile;
}
#if ENABLE_HUSH_MODE_X
if (G.x_mode_fd > 0 && fd == G.x_mode_fd) {
G.x_mode_fd = xdup_CLOEXEC_and_close(fd, avoid_fd);
return 1; /* "found and moved" */
}
#endif
return 0; /* "not in the list" */
}
#if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
static void close_all_HFILE_list(void)
{
HFILE *fl = G.HFILE_list;
while (fl) {
/* hfclose would also free HFILE object.
* It is disastrous if we share memory with a vforked parent.
* I'm not sure we never come here after vfork.
* Therefore just close fd, nothing more.
*
* ">" instead of ">=": we don't close fd#0,
* interactive shell uses hfopen(NULL) as stdin input
* which has fl->fd == 0, but fd#0 gets redirected in pipes.
* If we'd close it here, then e.g. interactive "set | sort"
* with NOFORKed sort, would have sort's input fd closed.
*/
if (fl->fd > 0)
/*hfclose(fl); - unsafe */
close(fl->fd);
fl = fl->next_hfile;
}
}
#endif
static int fd_in_HFILEs(int fd)
{
HFILE *fl = G.HFILE_list;
while (fl) {
if (fl->fd == fd)
return 1;
fl = fl->next_hfile;
}
return 0;
}
/* Helpers for setting new $n and restoring them back
*/
typedef struct save_arg_t {
char *sv_argv0;
char **sv_g_argv;
int sv_g_argc;
IF_HUSH_SET(smallint sv_g_malloced;)
} save_arg_t;
static void save_and_replace_G_args(save_arg_t *sv, char **argv)
{
sv->sv_argv0 = argv[0];
sv->sv_g_argv = G.global_argv;
sv->sv_g_argc = G.global_argc;
IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
argv[0] = G.global_argv[0]; /* retain $0 */
G.global_argv = argv;
IF_HUSH_SET(G.global_args_malloced = 0;)
G.global_argc = 1 + string_array_len(argv + 1);
}
static void restore_G_args(save_arg_t *sv, char **argv)
{
#if ENABLE_HUSH_SET
if (G.global_args_malloced) {
/* someone ran "set -- arg1 arg2 ...", undo */
char **pp = G.global_argv;
while (*++pp) /* note: does not free $0 */
free(*pp);
free(G.global_argv);
}
#endif
argv[0] = sv->sv_argv0;
G.global_argv = sv->sv_g_argv;
G.global_argc = sv->sv_g_argc;
IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
}
/* Basic theory of signal handling in shell
* ========================================
* This does not describe what hush does, rather, it is current understanding
* what it _should_ do. If it doesn't, it's a bug.
* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
*
* Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
* is finished or backgrounded. It is the same in interactive and
* non-interactive shells, and is the same regardless of whether
* a user trap handler is installed or a shell special one is in effect.
* ^C or ^Z from keyboard seems to execute "at once" because it usually
* backgrounds (i.e. stops) or kills all members of currently running
* pipe.
*
* Wait builtin is interruptible by signals for which user trap is set
* or by SIGINT in interactive shell.
*
* Trap handlers will execute even within trap handlers. (right?)
*
* User trap handlers are forgotten when subshell ("(cmd)") is entered,
* except for handlers set to '' (empty string).
*
* If job control is off, backgrounded commands ("cmd &")
* have SIGINT, SIGQUIT set to SIG_IGN.
*
* Commands which are run in command substitution ("`cmd`")
* have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
*
* Ordinary commands have signals set to SIG_IGN/DFL as inherited
* by the shell from its parent.
*
* Signals which differ from SIG_DFL action
* (note: child (i.e., [v]forked) shell is not an interactive shell):
*
* SIGQUIT: ignore
* SIGTERM (interactive): ignore
* SIGHUP (interactive):
* send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
* SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
* Note that ^Z is handled not by trapping SIGTSTP, but by seeing
* that all pipe members are stopped. Try this in bash:
* while :; do :; done - ^Z does not background it
* (while :; do :; done) - ^Z backgrounds it
* SIGINT (interactive): wait for last pipe, ignore the rest
* of the command line, show prompt. NB: ^C does not send SIGINT
* to interactive shell while shell is waiting for a pipe,
* since shell is bg'ed (is not in foreground process group).
* Example 1: this waits 5 sec, but does not execute ls:
* "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
* Example 2: this does not wait and does not execute ls:
* "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
* Example 3: this does not wait 5 sec, but executes ls:
* "sleep 5; ls -l" + press ^C
* Example 4: this does not wait and does not execute ls:
* "sleep 5 & wait; ls -l" + press ^C
*
* (What happens to signals which are IGN on shell start?)
* (What happens with signal mask on shell start?)
*
* Old implementation
* ==================
* We use in-kernel pending signal mask to determine which signals were sent.
* We block all signals which we don't want to take action immediately,
* i.e. we block all signals which need to have special handling as described
* above, and all signals which have traps set.
* After each pipe execution, we extract any pending signals via sigtimedwait()
* and act on them.
*
* unsigned special_sig_mask: a mask of such "special" signals
* sigset_t blocked_set: current blocked signal set
*
* "trap - SIGxxx":
* clear bit in blocked_set unless it is also in special_sig_mask
* "trap 'cmd' SIGxxx":
* set bit in blocked_set (even if 'cmd' is '')
* after [v]fork, if we plan to be a shell:
* unblock signals with special interactive handling
* (child shell is not interactive),
* unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
* after [v]fork, if we plan to exec:
* POSIX says fork clears pending signal mask in child - no need to clear it.
* Restore blocked signal set to one inherited by shell just prior to exec.
*
* Note: as a result, we do not use signal handlers much. The only uses
* are to count SIGCHLDs
* and to restore tty pgrp on signal-induced exit.
*
* Note 2 (compat):
* Standard says "When a subshell is entered, traps that are not being ignored
* are set to the default actions". bash interprets it so that traps which
* are set to '' (ignore) are NOT reset to defaults. We do the same.
*
* Problem: the above approach makes it unwieldy to catch signals while
* we are in read builtin, or while we read commands from stdin:
* masked signals are not visible!
*
* New implementation
* ==================
* We record each signal we are interested in by installing signal handler
* for them - a bit like emulating kernel pending signal mask in userspace.
* We are interested in: signals which need to have special handling
* as described above, and all signals which have traps set.
* Signals are recorded in pending_set.
* After each pipe execution, we extract any pending signals
* and act on them.
*
* unsigned special_sig_mask: a mask of shell-special signals.
* unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
* char *traps[sig] if trap for sig is set (even if it's '').
* sigset_t pending_set: set of sigs we received.
*
* "trap - SIGxxx":
* if sig is in special_sig_mask, set handler back to:
* record_pending_signo, or to IGN if it's a tty stop signal
* if sig is in fatal_sig_mask, set handler back to sigexit.
* else: set handler back to SIG_DFL
* "trap 'cmd' SIGxxx":
* set handler to record_pending_signo.
* "trap '' SIGxxx":
* set handler to SIG_IGN.
* after [v]fork, if we plan to be a shell:
* set signals with special interactive handling to SIG_DFL
* (because child shell is not interactive),
* unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
* after [v]fork, if we plan to exec:
* POSIX says fork clears pending signal mask in child - no need to clear it.
*
* To make wait builtin interruptible, we handle SIGCHLD as special signal,
* otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
*
* Note (compat):
* Standard says "When a subshell is entered, traps that are not being ignored
* are set to the default actions". bash interprets it so that traps which
* are set to '' (ignore) are NOT reset to defaults. We do the same.
*/
enum {
SPECIAL_INTERACTIVE_SIGS = 0
| (1 << SIGTERM)
| (1 << SIGINT)
| (1 << SIGHUP)
,
SPECIAL_JOBSTOP_SIGS = 0
#if ENABLE_HUSH_JOB
| (1 << SIGTTIN)
| (1 << SIGTTOU)
| (1 << SIGTSTP)
#endif
,
};
static void record_pending_signo(int sig)
{
sigaddset(&G.pending_set, sig);
#if ENABLE_HUSH_FAST
if (sig == SIGCHLD) {
G.count_SIGCHLD++;
//bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
}
#endif
}
static sighandler_t install_sighandler(int sig, sighandler_t handler)
{
struct sigaction old_sa;
/* We could use signal() to install handlers... almost:
* except that we need to mask ALL signals while handlers run.
* I saw signal nesting in strace, race window isn't small.
* SA_RESTART is also needed, but in Linux, signal()
* sets SA_RESTART too.
*/
/* memset(&G.sa, 0, sizeof(G.sa)); - already done */
/* sigfillset(&G.sa.sa_mask); - already done */
/* G.sa.sa_flags = SA_RESTART; - already done */
G.sa.sa_handler = handler;
sigaction(sig, &G.sa, &old_sa);
return old_sa.sa_handler;
}
static void hush_exit(int exitcode) NORETURN;
static void restore_ttypgrp_and__exit(void) NORETURN;
static void restore_ttypgrp_and__exit(void)
{
/* xfunc has failed! die die die */
/* no EXIT traps, this is an escape hatch! */
G.exiting = 1;
hush_exit(xfunc_error_retval);
}
#if ENABLE_HUSH_JOB
/* Needed only on some libc:
* It was observed that on exit(), fgetc'ed buffered data
* gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
* With the net effect that even after fork(), not vfork(),
* exit() in NOEXECed applet in "sh SCRIPT":
* noexec_applet_here
* echo END_OF_SCRIPT
* lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
* This makes "echo END_OF_SCRIPT" executed twice.
* Similar problems can be seen with msg_and_die_if_script() -> xfunc_die()
* and in `cmd` handling.
* If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
*/
static void fflush_and__exit(void) NORETURN;
static void fflush_and__exit(void)
{
fflush_all();
_exit(xfunc_error_retval);
}
/* After [v]fork, in child: do not restore tty pgrp on xfunc death */
# define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
/* After [v]fork, in parent: restore tty pgrp on xfunc death */
# define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
/* Restores tty foreground process group, and exits.
* May be called as signal handler for fatal signal
* (will resend signal to itself, producing correct exit state)
* or called directly with -EXITCODE.
* We also call it if xfunc is exiting.
*/
static void sigexit(int sig) NORETURN;
static void sigexit(int sig)
{
/* Careful: we can end up here after [v]fork. Do not restore
* tty pgrp then, only top-level shell process does that */
if (G_saved_tty_pgrp && getpid() == G.root_pid) {
/* Disable all signals: job control, SIGPIPE, etc.
* Mostly paranoid measure, to prevent infinite SIGTTOU.
*/
sigprocmask_allsigs(SIG_BLOCK);
tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
}
/* Not a signal, just exit */
if (sig <= 0)
_exit(- sig);
kill_myself_with_sig(sig); /* does not return */
}
#else
# define disable_restore_tty_pgrp_on_exit() ((void)0)
# define enable_restore_tty_pgrp_on_exit() ((void)0)
#endif
static sighandler_t pick_sighandler(unsigned sig)
{
sighandler_t handler = SIG_DFL;
if (sig < sizeof(unsigned)*8) {
unsigned sigmask = (1 << sig);
#if ENABLE_HUSH_JOB
/* is sig fatal? */
if (G_fatal_sig_mask & sigmask)
handler = sigexit;
else
#endif
/* sig has special handling? */
if (G.special_sig_mask & sigmask) {
handler = record_pending_signo;
/* TTIN/TTOU/TSTP can't be set to record_pending_signo
* in order to ignore them: they will be raised
* in an endless loop when we try to do some
* terminal ioctls! We do have to _ignore_ these.
*/
if (SPECIAL_JOBSTOP_SIGS & sigmask)
handler = SIG_IGN;
}
}
return handler;
}
/* Restores tty foreground process group, and exits. */
static void hush_exit(int exitcode)
{
#if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
save_history(G.line_input_state);
#endif
fflush_all();
if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
char *argv[3];
/* argv[0] is unused */
argv[1] = xstrdup(G_traps[0]); /* copy, since EXIT trap handler may modify G_traps[0] */
argv[2] = NULL;
G.exiting = 1; /* prevent EXIT trap recursion */
/* Note: G_traps[0] is not cleared!
* "trap" will still show it, if executed
* in the handler */
builtin_eval(argv);
}
#if ENABLE_FEATURE_CLEAN_UP
{
struct variable *cur_var;
if (G.cwd != bb_msg_unknown)
free((char*)G.cwd);
cur_var = G.top_var;
while (cur_var) {
struct variable *tmp = cur_var;
if (!cur_var->max_len)
free(cur_var->varstr);
cur_var = cur_var->next;
free(tmp);
}
}
#endif
fflush_all();
#if ENABLE_HUSH_JOB
sigexit(- (exitcode & 0xff));
#else
_exit(exitcode);
#endif
}
//TODO: return a mask of ALL handled sigs?
static int check_and_run_traps(void)
{
int last_sig = 0;
while (1) {
int sig;
if (sigisemptyset(&G.pending_set))
break;
sig = 0;
do {
sig++;
if (sigismember(&G.pending_set, sig)) {
sigdelset(&G.pending_set, sig);
goto got_sig;
}
} while (sig < NSIG);
break;
got_sig:
if (G_traps && G_traps[sig]) {
debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
if (G_traps[sig][0]) {
/* We have user-defined handler */
smalluint save_rcode;
char *argv[3];
/* argv[0] is unused */
argv[1] = xstrdup(G_traps[sig]);
/* why strdup? trap can modify itself: trap 'trap "echo oops" INT' INT */
argv[2] = NULL;
save_rcode = G.last_exitcode;
builtin_eval(argv);
free(argv[1]);
//FIXME: shouldn't it be set to 128 + sig instead?
G.last_exitcode = save_rcode;
last_sig = sig;
} /* else: "" trap, ignoring signal */
continue;
}
/* not a trap: special action */
switch (sig) {
case SIGINT:
debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
G.flag_SIGINT = 1;
last_sig = sig;
break;
#if ENABLE_HUSH_JOB
case SIGHUP: {
//TODO: why are we doing this? ash and dash don't do this,
//they have no handler for SIGHUP at all,
//they rely on kernel to send SIGHUP+SIGCONT to orphaned process groups
struct pipe *job;
debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
/* bash is observed to signal whole process groups,
* not individual processes */
for (job = G.job_list; job; job = job->next) {
if (job->pgrp <= 0)
continue;
debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
if (kill(- job->pgrp, SIGHUP) == 0)
kill(- job->pgrp, SIGCONT);
}
sigexit(SIGHUP);
}
#endif
#if ENABLE_HUSH_FAST
case SIGCHLD:
debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
G.count_SIGCHLD++;
//bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
/* Note:
* We don't do 'last_sig = sig' here -> NOT returning this sig.
* This simplifies wait builtin a bit.
*/
break;
#endif
default: /* ignored: */
debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
/* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
/* Note:
* We don't do 'last_sig = sig' here -> NOT returning this sig.
* Example: wait is not interrupted by TERM
* in interactive shell, because TERM is ignored.
*/
break;
}
}
return last_sig;
}
static const char *get_cwd(int force)
{
if (force || G.cwd == NULL) {
/* xrealloc_getcwd_or_warn(arg) calls free(arg),
* we must not try to free(bb_msg_unknown) */
if (G.cwd == bb_msg_unknown)
G.cwd = NULL;
G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
if (!G.cwd)
G.cwd = bb_msg_unknown;
}
return G.cwd;
}
/*
* Shell and environment variable support
*/
static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
{
struct variable **pp;
struct variable *cur;
pp = &G.top_var;
while ((cur = *pp) != NULL) {
if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
return pp;
pp = &cur->next;
}
return NULL;
}
static const char* FAST_FUNC get_local_var_value(const char *name)
{
struct variable **vpp;
unsigned len = strlen(name);
if (G.expanded_assignments) {
char **cpp = G.expanded_assignments;
while (*cpp) {
char *cp = *cpp;
if (strncmp(cp, name, len) == 0 && cp[len] == '=')
return cp + len + 1;
cpp++;
}
}
vpp = get_ptr_to_local_var(name, len);
if (vpp)
return (*vpp)->varstr + len + 1;
if (strcmp(name, "PPID") == 0)
return utoa(G.root_ppid);
// bash compat: UID? EUID?
#if ENABLE_HUSH_RANDOM_SUPPORT
if (strcmp(name, "RANDOM") == 0)
return utoa(next_random(&G.random_gen));
#endif
#if BASH_EPOCH_VARS
{
const char *fmt = NULL;
if (strcmp(name, "EPOCHSECONDS") == 0)
fmt = "%lu";
else if (strcmp(name, "EPOCHREALTIME") == 0)
fmt = "%lu.%06u";
if (fmt) {
struct timeval tv;
gettimeofday(&tv, NULL);
sprintf(G.epoch_buf, fmt, (unsigned long)tv.tv_sec,
(unsigned)tv.tv_usec);
return G.epoch_buf;
}
}
#endif
return NULL;
}
#if (ENABLE_HUSH_INTERACTIVE && ENABLE_FEATURE_EDITING_FANCY_PROMPT) \
|| (ENABLE_HUSH_LINENO_VAR || ENABLE_HUSH_GETOPTS)
static void handle_changed_special_names(const char *name, unsigned name_len)
{
if (ENABLE_HUSH_INTERACTIVE && ENABLE_FEATURE_EDITING_FANCY_PROMPT
&& G_interactive_fd
&& name_len == 3 && name[0] == 'P' && name[1] == 'S'
) {
cmdedit_update_prompt();
return;
}
if ((ENABLE_HUSH_LINENO_VAR || ENABLE_HUSH_GETOPTS)
&& name_len == 6
) {
#if ENABLE_HUSH_LINENO_VAR
if (strncmp(name, "LINENO", 6) == 0) {
G.lineno_var = NULL;
return;
}
#endif
#if ENABLE_HUSH_GETOPTS
if (strncmp(name, "OPTIND", 6) == 0) {
G.getopt_count = 0;
return;
}
#endif
}
}
#else
/* Do not even bother evaluating arguments */
# define handle_changed_special_names(...) ((void)0)
#endif
/* str holds "NAME=VAL" and is expected to be malloced.
* We take ownership of it.
*/
#define SETFLAG_EXPORT (1 << 0)
#define SETFLAG_UNEXPORT (1 << 1)
#define SETFLAG_MAKE_RO (1 << 2)
#define SETFLAG_VARLVL_SHIFT 3
static int set_local_var(char *str, unsigned flags)
{
struct variable **cur_pp;
struct variable *cur;
char *free_me = NULL;
char *eq_sign;
int name_len;
int retval;
unsigned local_lvl = (flags >> SETFLAG_VARLVL_SHIFT);
eq_sign = strchr(str, '=');
if (HUSH_DEBUG && !eq_sign)
bb_error_msg_and_die("BUG in setvar");
name_len = eq_sign - str + 1; /* including '=' */
cur_pp = &G.top_var;
while ((cur = *cur_pp) != NULL) {
if (strncmp(cur->varstr, str, name_len) != 0) {
cur_pp = &cur->next;
continue;
}
/* We found an existing var with this name */
if (cur->flg_read_only) {
bb_error_msg("%s: readonly variable", str);
free(str);
//NOTE: in bash, assignment in "export READONLY_VAR=Z" fails, and sets $?=1,
//but export per se succeeds (does put the var in env). We don't mimic that.
return -1;
}
if (flags & SETFLAG_UNEXPORT) { // && cur->flg_export ?
debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
*eq_sign = '\0';
unsetenv(str);
*eq_sign = '=';
}
if (cur->var_nest_level < local_lvl) {
/* bash 3.2.33(1) and exported vars:
* # export z=z
* # f() { local z=a; env | grep ^z; }
* # f
* z=a
* # env | grep ^z
* z=z
*/
if (cur->flg_export)
flags |= SETFLAG_EXPORT;
/* New variable is local ("local VAR=VAL" or
* "VAR=VAL cmd")
* and existing one is global, or local
* on a lower level that new one.
* Remove it from global variable list:
*/
*cur_pp = cur->next;
if (G.shadowed_vars_pp) {
/* Save in "shadowed" list */
debug_printf_env("shadowing %s'%s'/%u by '%s'/%u\n",
cur->flg_export ? "exported " : "",
cur->varstr, cur->var_nest_level, str, local_lvl
);
cur->next = *G.shadowed_vars_pp;
*G.shadowed_vars_pp = cur;
} else {
/* Came from pseudo_exec_argv(), no need to save: delete it */
debug_printf_env("shadow-deleting %s'%s'/%u by '%s'/%u\n",
cur->flg_export ? "exported " : "",
cur->varstr, cur->var_nest_level, str, local_lvl
);
if (cur->max_len == 0) /* allocated "VAR=VAL"? */
free_me = cur->varstr; /* then free it later */
free(cur);
}
break;
}
if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
debug_printf_env("assignement '%s' does not change anything\n", str);
free_and_exp:
free(str);
goto exp;
}
/* Replace the value in the found "struct variable" */
if (cur->max_len != 0) {
if (cur->max_len >= strnlen(str, cur->max_len + 1)) {
/* This one is from startup env, reuse space */
debug_printf_env("reusing startup env for '%s'\n", str);
strcpy(cur->varstr, str);
goto free_and_exp;
}
/* Can't reuse */
cur->max_len = 0;
goto set_str_and_exp;
}
/* max_len == 0 signifies "malloced" var, which we can
* (and have to) free. But we can't free(cur->varstr) here:
* if cur->flg_export is 1, it is in the environment.
* We should either unsetenv+free, or wait until putenv,
* then putenv(new)+free(old).
*/
free_me = cur->varstr;
goto set_str_and_exp;
}
/* Not found or shadowed - create new variable struct */
debug_printf_env("%s: alloc new var '%s'/%u\n", __func__, str, local_lvl);
cur = xzalloc(sizeof(*cur));
cur->var_nest_level = local_lvl;
cur->next = *cur_pp;
*cur_pp = cur;
set_str_and_exp:
cur->varstr = str;
exp:
#if !BB_MMU || ENABLE_HUSH_READONLY
if (flags & SETFLAG_MAKE_RO) {
cur->flg_read_only = 1;
}
#endif
if (flags & SETFLAG_EXPORT)
cur->flg_export = 1;
retval = 0;
if (cur->flg_export) {
if (flags & SETFLAG_UNEXPORT) {
cur->flg_export = 0;
/* unsetenv was already done */
} else {
debug_printf_env("%s: putenv '%s'/%u\n", __func__, cur->varstr, cur->var_nest_level);
retval = putenv(cur->varstr);
/* fall through to "free(free_me)" -
* only now we can free old exported malloced string
*/
}
}
free(free_me);
handle_changed_special_names(cur->varstr, name_len - 1);
return retval;
}
static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
{
char *var = xasprintf("%s=%s", name, val);
set_local_var(var, /*flag:*/ 0);
}
/* Used at startup and after each cd */
static void set_pwd_var(unsigned flag)
{
set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)), flag);
}
#if ENABLE_HUSH_UNSET || ENABLE_HUSH_GETOPTS
static int unset_local_var_len(const char *name, int name_len)
{
struct variable *cur;
struct variable **cur_pp;
cur_pp = &G.top_var;
while ((cur = *cur_pp) != NULL) {
if (strncmp(cur->varstr, name, name_len) == 0
&& cur->varstr[name_len] == '='
) {
if (cur->flg_read_only) {
bb_error_msg("%s: readonly variable", name);
return EXIT_FAILURE;
}
*cur_pp = cur->next;
debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
bb_unsetenv(cur->varstr);
if (!cur->max_len)
free(cur->varstr);
free(cur);
break;
}
cur_pp = &cur->next;
}
/* Handle "unset PS1" et al even if did not find the variable to unset */
handle_changed_special_names(name, name_len);
return EXIT_SUCCESS;
}
static int unset_local_var(const char *name)
{
return unset_local_var_len(name, strlen(name));
}
#endif
/*
* Helpers for "var1=val1 var2=val2 cmd" feature
*/
static void add_vars(struct variable *var)
{
struct variable *next;
while (var) {
next = var->next;
var->next = G.top_var;
G.top_var = var;
if (var->flg_export) {
debug_printf_env("%s: restoring exported '%s'/%u\n", __func__, var->varstr, var->var_nest_level);
putenv(var->varstr);
} else {
debug_printf_env("%s: restoring variable '%s'/%u\n", __func__, var->varstr, var->var_nest_level);
}
/* Testcase (interactive):
* f() { local PS1='\w \$ '; }; f
* the below call is needed to notice restored PS1 when f returns.
*/
handle_changed_special_names(var->varstr, endofname(var->varstr) - var->varstr);
var = next;
}
}
/* We put strings[i] into variable table and possibly putenv them.
* If variable is read only, we can free the strings[i]
* which attempts to overwrite it.
* The strings[] vector itself is freed.
*/
static void set_vars_and_save_old(char **strings)
{
char **s;
if (!strings)
return;
s = strings;
while (*s) {
struct variable *var_p;
struct variable **var_pp;
char *eq;
eq = strchr(*s, '=');
if (HUSH_DEBUG && !eq)
bb_error_msg_and_die("BUG in varexp4");
var_pp = get_ptr_to_local_var(*s, eq - *s);
if (var_pp) {
var_p = *var_pp;
if (var_p->flg_read_only) {
char **p;
bb_error_msg("%s: readonly variable", *s);
/*
* "VAR=V BLTIN" unsets VARs after BLTIN completes.
* If VAR is readonly, leaving it in the list
* after asssignment error (msg above)
* causes doubled error message later, on unset.
*/
debug_printf_env("removing/freeing '%s' element\n", *s);
free(*s);
p = s;
do { *p = p[1]; p++; } while (*p);
goto next;
}
/* below, set_local_var() with nest level will
* "shadow" (remove) this variable from
* global linked list.
*/
}
debug_printf_env("%s: env override '%s'/%u\n", __func__, *s, G.var_nest_level);
set_local_var(*s, (G.var_nest_level << SETFLAG_VARLVL_SHIFT) | SETFLAG_EXPORT);
s++;
next: ;
}
free(strings);
}
/*
* Unicode helper
*/
static void reinit_unicode_for_hush(void)
{
/* Unicode support should be activated even if LANG is set
* _during_ shell execution, not only if it was set when
* shell was started. Therefore, re-check LANG every time:
*/
if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
|| ENABLE_UNICODE_USING_LOCALE
) {
const char *s = get_local_var_value("LC_ALL");
if (!s) s = get_local_var_value("LC_CTYPE");
if (!s) s = get_local_var_value("LANG");
reinit_unicode(s);
}
}
/*
* in_str support (strings, and "strings" read from files).
*/
#if ENABLE_HUSH_INTERACTIVE
/* To test correct lineedit/interactive behavior, type from command line:
* echo $P\
* \
* AT\
* H\
* \
* It exercises a lot of corner cases.
*/
# if ENABLE_FEATURE_EDITING_FANCY_PROMPT
static void cmdedit_update_prompt(void)
{
G.PS1 = get_local_var_value("PS1");
if (G.PS1 == NULL)
G.PS1 = "";
G.PS2 = get_local_var_value("PS2");
if (G.PS2 == NULL)
G.PS2 = "";
}
# endif
static const char *setup_prompt_string(void)
{
const char *prompt_str;
debug_printf_prompt("%s promptmode:%d\n", __func__, G.promptmode);
IF_FEATURE_EDITING_FANCY_PROMPT( prompt_str = G.PS2;)
IF_NOT_FEATURE_EDITING_FANCY_PROMPT(prompt_str = "> ";)
if (G.promptmode == 0) { /* PS1 */
if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
/* No fancy prompts supported, (re)generate "CURDIR $ " by hand */
free((char*)G.PS1);
/* bash uses $PWD value, even if it is set by user.
* It uses current dir only if PWD is unset.
* We always use current dir. */
G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
}
prompt_str = G.PS1;
}
debug_printf("prompt_str '%s'\n", prompt_str);
return prompt_str;
}
static int get_user_input(struct in_str *i)
{
int r;
const char *prompt_str;
prompt_str = setup_prompt_string();
# if ENABLE_FEATURE_EDITING
for (;;) {
reinit_unicode_for_hush();
if (G.flag_SIGINT) {
/* There was ^C'ed, make it look prettier: */
bb_putchar('\n');
G.flag_SIGINT = 0;
}
/* buglet: SIGINT will not make new prompt to appear _at once_,
* only after <Enter>. (^C works immediately) */
r = read_line_input(G.line_input_state, prompt_str,
G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1
);
/* read_line_input intercepts ^C, "convert" it to SIGINT */
if (r == 0)
raise(SIGINT);
check_and_run_traps();
if (r != 0 && !G.flag_SIGINT)
break;
/* ^C or SIGINT: repeat */
/* bash prints ^C even on real SIGINT (non-kbd generated) */
write(STDOUT_FILENO, "^C", 2);
G.last_exitcode = 128 + SIGINT;
}
if (r < 0) {
/* EOF/error detected */
i->p = NULL;
i->peek_buf[0] = r = EOF;
return r;
}
i->p = G.user_input_buf;
return (unsigned char)*i->p++;
# else
for (;;) {
G.flag_SIGINT = 0;
if (i->last_char == '\0' || i->last_char == '\n') {
/* Why check_and_run_traps here? Try this interactively:
* $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
* $ <[enter], repeatedly...>
* Without check_and_run_traps, handler never runs.
*/
check_and_run_traps();
fputs(prompt_str, stdout);
}
fflush_all();
//FIXME: here ^C or SIGINT will have effect only after <Enter>
r = hfgetc(i->file);
/* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
* no ^C masking happens during fgetc, no special code for ^C:
* it generates SIGINT as usual.
*/
check_and_run_traps();
if (G.flag_SIGINT)
G.last_exitcode = 128 + SIGINT;
if (r != '\0')
break;
}
return r;
# endif
}
/* This is the magic location that prints prompts
* and gets data back from the user */
static int fgetc_interactive(struct in_str *i)
{
int ch;
/* If it's interactive stdin, get new line. */
if (G_interactive_fd && i->file->is_stdin) {
/* Returns first char (or EOF), the rest is in i->p[] */
ch = get_user_input(i);
G.promptmode = 1; /* PS2 */
debug_printf_prompt("%s promptmode=%d\n", __func__, G.promptmode);
} else {
/* Not stdin: script file, sourced file, etc */
do ch = hfgetc(i->file); while (ch == '\0');
}
return ch;
}
#else
static ALWAYS_INLINE int fgetc_interactive(struct in_str *i)
{
int ch;
do ch = hfgetc(i->file); while (ch == '\0');
return ch;
}
#endif /* INTERACTIVE */
static int i_getch(struct in_str *i)
{
int ch;
if (!i->file) {
/* string-based in_str */
ch = (unsigned char)*i->p;
if (ch != '\0') {
i->p++;
i->last_char = ch;
return ch;
}
return EOF;
}
/* FILE-based in_str */
#if ENABLE_FEATURE_EDITING
/* This can be stdin, check line editing char[] buffer */
if (i->p && *i->p != '\0') {
ch = (unsigned char)*i->p++;
goto out;
}
#endif
/* peek_buf[] is an int array, not char. Can contain EOF. */
ch = i->peek_buf[0];
if (ch != 0) {
int ch2 = i->peek_buf[1];
i->peek_buf[0] = ch2;
if (ch2 == 0) /* very likely, avoid redundant write */
goto out;
i->peek_buf[1] = 0;
goto out;
}
ch = fgetc_interactive(i);
out:
debug_printf("file_get: got '%c' %d\n", ch, ch);
i->last_char = ch;
#if ENABLE_HUSH_LINENO_VAR
if (ch == '\n') {
G.lineno++;
debug_printf_parse("G.lineno++ = %u\n", G.lineno);
}
#endif
return ch;
}
static int i_peek(struct in_str *i)
{
int ch;
if (!i->file) {
/* string-based in_str */
/* Doesn't report EOF on NUL. None of the callers care. */
return (unsigned char)*i->p;
}
/* FILE-based in_str */
#if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
/* This can be stdin, check line editing char[] buffer */
if (i->p && *i->p != '\0')
return (unsigned char)*i->p;
#endif
/* peek_buf[] is an int array, not char. Can contain EOF. */
ch = i->peek_buf[0];
if (ch != 0)
return ch;
/* Need to get a new char */
ch = fgetc_interactive(i);
debug_printf("file_peek: got '%c' %d\n", ch, ch);
/* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
#if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
if (i->p) {
i->p -= 1;
return ch;
}
#endif
i->peek_buf[0] = ch;
/*i->peek_buf[1] = 0; - already is */
return ch;
}
/* Only ever called if i_peek() was called, and did not return EOF.
* IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
* not end-of-line. Therefore we never need to read a new editing line here.
*/
static int i_peek2(struct in_str *i)
{
int ch;
/* There are two cases when i->p[] buffer exists.
* (1) it's a string in_str.
* (2) It's a file, and we have a saved line editing buffer.
* In both cases, we know that i->p[0] exists and not NUL, and
* the peek2 result is in i->p[1].
*/
if (i->p)
return (unsigned char)i->p[1];
/* Now we know it is a file-based in_str. */
/* peek_buf[] is an int array, not char. Can contain EOF. */
/* Is there 2nd char? */
ch = i->peek_buf[1];
if (ch == 0) {
/* We did not read it yet, get it now */
do ch = hfgetc(i->file); while (ch == '\0');
i->peek_buf[1] = ch;
}
debug_printf("file_peek2: got '%c' %d\n", ch, ch);
return ch;
}
static int i_getch_and_eat_bkslash_nl(struct in_str *input)
{
for (;;) {
int ch, ch2;
ch = i_getch(input);
if (ch != '\\')
return ch;
ch2 = i_peek(input);
if (ch2 != '\n')
return ch;
/* backslash+newline, skip it */
i_getch(input);
}
}
/* Note: this function _eats_ \<newline> pairs, safe to use plain
* i_getch() after it instead of i_getch_and_eat_bkslash_nl().
*/
static int i_peek_and_eat_bkslash_nl(struct in_str *input)
{
for (;;) {
int ch, ch2;
ch = i_peek(input);
if (ch != '\\')
return ch;
ch2 = i_peek2(input);
if (ch2 != '\n')
return ch;
/* backslash+newline, skip it */
i_getch(input);
i_getch(input);
}
}
static void setup_file_in_str(struct in_str *i, HFILE *fp)
{
memset(i, 0, sizeof(*i));
i->file = fp;
/* i->p = NULL; */
}
static void setup_string_in_str(struct in_str *i, const char *s)
{
memset(i, 0, sizeof(*i));
/*i->file = NULL */;
i->p = s;
}
/*
* o_string support
*/
#define B_CHUNK (32 * sizeof(char*))
static void o_reset_to_empty_unquoted(o_string *o)
{
o->length = 0;
o->has_quoted_part = 0;
if (o->data)
o->data[0] = '\0';
}
static void o_free_and_set_NULL(o_string *o)
{
free(o->data);
memset(o, 0, sizeof(*o));
}
static ALWAYS_INLINE void o_free(o_string *o)
{
free(o->data);
}
static void o_grow_by(o_string *o, int len)
{
if (o->length + len > o->maxlen) {
o->maxlen += (2 * len) | (B_CHUNK-1);
o->data = xrealloc(o->data, 1 + o->maxlen);
}
}
static void o_addchr(o_string *o, int ch)
{
debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
if (o->length < o->maxlen) {
/* likely. avoid o_grow_by() call */
add:
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
return;
}
o_grow_by(o, 1);
goto add;
}
#if 0
/* Valid only if we know o_string is not empty */
static void o_delchr(o_string *o)
{
o->length--;
o->data[o->length] = '\0';
}
#endif
static void o_addblock(o_string *o, const char *str, int len)
{
o_grow_by(o, len);
((char*)mempcpy(&o->data[o->length], str, len))[0] = '\0';
o->length += len;
}
static void o_addstr(o_string *o, const char *str)
{
o_addblock(o, str, strlen(str));
}
static void o_addstr_with_NUL(o_string *o, const char *str)
{
o_addblock(o, str, strlen(str) + 1);
}
#if !BB_MMU
static void nommu_addchr(o_string *o, int ch)
{
if (o)
o_addchr(o, ch);
}
#else
# define nommu_addchr(o, str) ((void)0)
#endif
#if ENABLE_HUSH_MODE_X
static void x_mode_addchr(int ch)
{
o_addchr(&G.x_mode_buf, ch);
}
static void x_mode_addstr(const char *str)
{
o_addstr(&G.x_mode_buf, str);
}
static void x_mode_addblock(const char *str, int len)
{
o_addblock(&G.x_mode_buf, str, len);
}
static void x_mode_prefix(void)
{
int n = G.x_mode_depth;
do x_mode_addchr('+'); while (--n >= 0);
}
static void x_mode_flush(void)
{
int len = G.x_mode_buf.length;
if (len <= 0)
return;
if (G.x_mode_fd > 0) {
G.x_mode_buf.data[len] = '\n';
full_write(G.x_mode_fd, G.x_mode_buf.data, len + 1);
}
G.x_mode_buf.length = 0;
}
#endif
/*
* HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
* Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
* Apparently, on unquoted $v bash still does globbing
* ("v='*.txt'; echo $v" prints all .txt files),
* but NOT brace expansion! Thus, there should be TWO independent
* quoting mechanisms on $v expansion side: one protects
* $v from brace expansion, and other additionally protects "$v" against globbing.
* We have only second one.
*/
#if ENABLE_HUSH_BRACE_EXPANSION
# define MAYBE_BRACES "{}"
#else
# define MAYBE_BRACES ""
#endif
/* My analysis of quoting semantics tells me that state information
* is associated with a destination, not a source.
*/
static void o_addqchr(o_string *o, int ch)
{
int sz = 1;
char *found = strchr("*?[\\" MAYBE_BRACES, ch);
if (found)
sz++;
o_grow_by(o, sz);
if (found) {
o->data[o->length] = '\\';
o->length++;
}
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
}
static void o_addQchr(o_string *o, int ch)
{
int sz = 1;
if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
&& strchr("*?[\\" MAYBE_BRACES, ch)
) {
sz++;
o->data[o->length] = '\\';
o->length++;
}
o_grow_by(o, sz);
o->data[o->length] = ch;
o->length++;
o->data[o->length] = '\0';
}
static void o_addqblock(o_string *o, const char *str, int len)
{
while (len) {
char ch;
int sz;
int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
if (ordinary_cnt > len) /* paranoia */
ordinary_cnt = len;
o_addblock(o, str, ordinary_cnt);
if (ordinary_cnt == len)
return; /* NUL is already added by o_addblock */
str += ordinary_cnt;
len -= ordinary_cnt + 1; /* we are processing + 1 char below */
ch = *str++;
sz = 1;
if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
sz++;
o->data[o->length] = '\\';
o->length++;
}
o_grow_by(o, sz);
o->data[o->length] = ch;
o->length++;
}
o->data[o->length] = '\0';
}
static void o_addQblock(o_string *o, const char *str, int len)
{
if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
o_addblock(o, str, len);
return;
}
o_addqblock(o, str, len);
}
static void o_addQstr(o_string *o, const char *str)
{
o_addQblock(o, str, strlen(str));
}
/* A special kind of o_string for $VAR and `cmd` expansion.
* It contains char* list[] at the beginning, which is grown in 16 element
* increments. Actual string data starts at the next multiple of 16 * (char*).
* list[i] contains an INDEX (int!) into this string data.
* It means that if list[] needs to grow, data needs to be moved higher up
* but list[i]'s need not be modified.
* NB: remembering how many list[i]'s you have there is crucial.
* o_finalize_list() operation post-processes this structure - calculates
* and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
*/
#if DEBUG_EXPAND || DEBUG_GLOB
static void debug_print_list(const char *prefix, o_string *o, int n)
{
char **list = (char**)o->data;
int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
int i = 0;
indent();
fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
prefix, list, n, string_start, o->length, o->maxlen,
!!(o->o_expflags & EXP_FLAG_GLOB),
o->has_quoted_part,
!!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
while (i < n) {
indent();
fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
o->data + (int)(uintptr_t)list[i] + string_start,
o->data + (int)(uintptr_t)list[i] + string_start);
i++;
}
if (n) {
const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
indent();
fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
}
}
#else
# define debug_print_list(prefix, o, n) ((void)0)
#endif
/* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
* in list[n] so that it points past last stored byte so far.
* It returns n+1. */
static int o_save_ptr_helper(o_string *o, int n)
{
char **list = (char**)o->data;
int string_start;
int string_len;
if (!o->has_empty_slot) {
string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
string_len = o->length - string_start;
if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
/* list[n] points to string_start, make space for 16 more pointers */
o->maxlen += 0x10 * sizeof(list[0]);
o->data = xrealloc(o->data, o->maxlen + 1);
list = (char**)o->data;
memmove(list + n + 0x10, list + n, string_len);
/*
* expand_on_ifs() has a "previous argv[] ends in IFS?"
* check. (grep for -prev-ifs-check-).
* Ensure that argv[-1][last] is not garbage
* but zero bytes, to save index check there.
*/
list[n + 0x10 - 1] = 0;
o->length += 0x10 * sizeof(list[0]);
} else {
debug_printf_list("list[%d]=%d string_start=%d\n",
n, string_len, string_start);
}
} else {
/* We have empty slot at list[n], reuse without growth */
string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
string_len = o->length - string_start;
debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
n, string_len, string_start);
o->has_empty_slot = 0;
}
o->has_quoted_part = 0;
list[n] = (char*)(uintptr_t)string_len;
return n + 1;
}
/* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
static int o_get_last_ptr(o_string *o, int n)
{
char **list = (char**)o->data;
int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
return ((int)(uintptr_t)list[n-1]) + string_start;
}
/*
* Globbing routines.
*
* Most words in commands need to be globbed, even ones which are
* (single or double) quoted. This stems from the possiblity of
* constructs like "abc"* and 'abc'* - these should be globbed.
* Having a different code path for fully-quoted strings ("abc",
* 'abc') would only help performance-wise, but we still need
* code for partially-quoted strings.
*
* Unfortunately, if we want to match bash and ash behavior in all cases,
* the logic can't be "shell-syntax argument is first transformed
* to a string, then globbed, and if globbing does not match anything,
* it is used verbatim". Here are two examples where it fails:
*
* echo 'b\*'?
*
* The globbing can't be avoided (because of '?' at the end).
* The glob pattern is: b\\\*? - IOW, both \ and * are literals
* and are glob-escaped. If this does not match, bash/ash print b\*?
* - IOW: they "unbackslash" the glob pattern.
* Now, look at this:
*
* v='\\\*'; echo b$v?
*
* The glob pattern is the same here: b\\\*? - the unquoted $v expansion
* should be used as glob pattern with no changes. However, if glob
* does not match, bash/ash print b\\\*? - NOT THE SAME as first example!
*
* ash implements this by having an encoded representation of the word
* to glob, which IS NOT THE SAME as the glob pattern - it has more data.
* Glob pattern is derived from it. If glob fails, the decision what result
* should be is made using that encoded representation. Not glob pattern.
*/
#if ENABLE_HUSH_BRACE_EXPANSION
/* There in a GNU extension, GLOB_BRACE, but it is not usable:
* first, it processes even {a} (no commas), second,
* I didn't manage to make it return strings when they don't match
* existing files. Need to re-implement it.
*/
/* Helper */
static int glob_needed(const char *s)
{
while (*s) {
if (*s == '\\') {
if (!s[1])
return 0;
s += 2;
continue;
}
if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
return 1;
s++;
}
return 0;
}
/* Return pointer to next closing brace or to comma */
static const char *next_brace_sub(const char *cp)
{
unsigned depth = 0;
cp++;
while (*cp != '\0') {
if (*cp == '\\') {
if (*++cp == '\0')
break;
cp++;
continue;
}
if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
break;
if (*cp++ == '{')
depth++;
}
return *cp != '\0' ? cp : NULL;
}
/* Recursive brace globber. Note: may garble pattern[]. */
static int glob_brace(char *pattern, o_string *o, int n)
{
char *new_pattern_buf;
const char *begin;
const char *next;
const char *rest;
const char *p;
size_t rest_len;
debug_printf_glob("glob_brace('%s')\n", pattern);
begin = pattern;
while (1) {
if (*begin == '\0')
goto simple_glob;
if (*begin == '{') {
/* Find the first sub-pattern and at the same time
* find the rest after the closing brace */
next = next_brace_sub(begin);
if (next == NULL) {
/* An illegal expression */
goto simple_glob;
}
if (*next == '}') {
/* "{abc}" with no commas - illegal
* brace expr, disregard and skip it */
begin = next + 1;
continue;
}
break;
}
if (*begin == '\\' && begin[1] != '\0')
begin++;
begin++;
}
debug_printf_glob("begin:%s\n", begin);
debug_printf_glob("next:%s\n", next);
/* Now find the end of the whole brace expression */
rest = next;
while (*rest != '}') {
rest = next_brace_sub(rest);
if (rest == NULL) {
/* An illegal expression */
goto simple_glob;
}
debug_printf_glob("rest:%s\n", rest);
}
rest_len = strlen(++rest) + 1;
/* We are sure the brace expression is well-formed */
/* Allocate working buffer large enough for our work */
new_pattern_buf = xmalloc(strlen(pattern));
/* We have a brace expression. BEGIN points to the opening {,
* NEXT points past the terminator of the first element, and REST
* points past the final }. We will accumulate result names from
* recursive runs for each brace alternative in the buffer using
* GLOB_APPEND. */
p = begin + 1;
while (1) {
/* Construct the new glob expression */
memcpy(
mempcpy(
mempcpy(new_pattern_buf,
/* We know the prefix for all sub-patterns */
pattern, begin - pattern),
p, next - p),
rest, rest_len);
/* Note: glob_brace() may garble new_pattern_buf[].
* That's why we re-copy prefix every time (1st memcpy above).
*/
n = glob_brace(new_pattern_buf, o, n);
if (*next == '}') {
/* We saw the last entry */
break;
}
p = next + 1;
next = next_brace_sub(next);
}
free(new_pattern_buf);
return n;
simple_glob:
{
int gr;
glob_t globdata;
memset(&globdata, 0, sizeof(globdata));
gr = glob(pattern, 0, NULL, &globdata);
debug_printf_glob("glob('%s'):%d\n", pattern, gr);
if (gr != 0) {
if (gr == GLOB_NOMATCH) {
globfree(&globdata);
/* NB: garbles parameter */
unbackslash(pattern);
o_addstr_with_NUL(o, pattern);
debug_printf_glob("glob pattern '%s' is literal\n", pattern);
return o_save_ptr_helper(o, n);
}
if (gr == GLOB_NOSPACE)
bb_die_memory_exhausted();
/* GLOB_ABORTED? Only happens with GLOB_ERR flag,
* but we didn't specify it. Paranoia again. */
bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
}
if (globdata.gl_pathv && globdata.gl_pathv[0]) {
char **argv = globdata.gl_pathv;
while (1) {
o_addstr_with_NUL(o, *argv);
n = o_save_ptr_helper(o, n);
argv++;
if (!*argv)
break;
}
}
globfree(&globdata);
}
return n;
}
/* Performs globbing on last list[],
* saving each result as a new list[].
*/
static int perform_glob(o_string *o, int n)
{
char *pattern, *copy;
debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
if (!o->data)
return o_save_ptr_helper(o, n);
pattern = o->data + o_get_last_ptr(o, n);
debug_printf_glob("glob pattern '%s'\n", pattern);
if (!glob_needed(pattern)) {
/* unbackslash last string in o in place, fix length */
o->length = unbackslash(pattern) - o->data;
debug_printf_glob("glob pattern '%s' is literal\n", pattern);
return o_save_ptr_helper(o, n);
}
copy = xstrdup(pattern);
/* "forget" pattern in o */
o->length = pattern - o->data;
n = glob_brace(copy, o, n);
free(copy);
if (DEBUG_GLOB)
debug_print_list("perform_glob returning", o, n);
return n;
}
#else /* !HUSH_BRACE_EXPANSION */
/* Helper */
static int glob_needed(const char *s)
{
while (*s) {
if (*s == '\\') {
if (!s[1])
return 0;
s += 2;
continue;
}
if (*s == '*' || *s == '[' || *s == '?')
return 1;
s++;
}
return 0;
}
/* Performs globbing on last list[],
* saving each result as a new list[].
*/
static int perform_glob(o_string *o, int n)
{
glob_t globdata;
int gr;
char *pattern;
debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
if (!o->data)
return o_save_ptr_helper(o, n);
pattern = o->data + o_get_last_ptr(o, n);
debug_printf_glob("glob pattern '%s'\n", pattern);
if (!glob_needed(pattern)) {
literal:
/* unbackslash last string in o in place, fix length */
o->length = unbackslash(pattern) - o->data;
debug_printf_glob("glob pattern '%s' is literal\n", pattern);
return o_save_ptr_helper(o, n);
}
memset(&globdata, 0, sizeof(globdata));
/* Can't use GLOB_NOCHECK: it does not unescape the string.
* If we glob "*.\*" and don't find anything, we need
* to fall back to using literal "*.*", but GLOB_NOCHECK
* will return "*.\*"!
*/
gr = glob(pattern, 0, NULL, &globdata);
debug_printf_glob("glob('%s'):%d\n", pattern, gr);
if (gr != 0) {
if (gr == GLOB_NOMATCH) {
globfree(&globdata);
goto literal;
}
if (gr == GLOB_NOSPACE)
bb_die_memory_exhausted();
/* GLOB_ABORTED? Only happens with GLOB_ERR flag,
* but we didn't specify it. Paranoia again. */
bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
}
if (globdata.gl_pathv && globdata.gl_pathv[0]) {
char **argv = globdata.gl_pathv;
/* "forget" pattern in o */
o->length = pattern - o->data;
while (1) {
o_addstr_with_NUL(o, *argv);
n = o_save_ptr_helper(o, n);
argv++;
if (!*argv)
break;
}
}
globfree(&globdata);
if (DEBUG_GLOB)
debug_print_list("perform_glob returning", o, n);
return n;
}
#endif /* !HUSH_BRACE_EXPANSION */
/* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
* Otherwise, just finish current list[] and start new */
static int o_save_ptr(o_string *o, int n)
{
if (o->o_expflags & EXP_FLAG_GLOB) {
/* If o->has_empty_slot, list[n] was already globbed
* (if it was requested back then when it was filled)
* so don't do that again! */
if (!o->has_empty_slot)
return perform_glob(o, n); /* o_save_ptr_helper is inside */
}
return o_save_ptr_helper(o, n);
}
/* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
static char **o_finalize_list(o_string *o, int n)
{
char **list;
int string_start;
if (DEBUG_EXPAND)
debug_print_list("finalized", o, n);
debug_printf_expand("finalized n:%d\n", n);
list = (char**)o->data;
string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
list[--n] = NULL;
while (n) {
n--;
list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
}
return list;
}
static void free_pipe_list(struct pipe *pi);
/* Returns pi->next - next pipe in the list */
static struct pipe *free_pipe(struct pipe *pi)
{
struct pipe *next;
int i;
debug_printf_clean("free_pipe (pid %d)\n", getpid());
for (i = 0; i < pi->num_cmds; i++) {
struct command *command;
struct redir_struct *r, *rnext;
command = &pi->cmds[i];
debug_printf_clean(" command %d:\n", i);
if (command->argv) {
if (DEBUG_CLEAN) {
int a;
char **p;
for (a = 0, p = command->argv; *p; a++, p++) {
debug_printf_clean(" argv[%d] = %s\n", a, *p);
}
}
free_strings(command->argv);
//command->argv = NULL;
}
/* not "else if": on syntax error, we may have both! */
if (command->group) {
debug_printf_clean(" begin group (cmd_type:%d)\n",
command->cmd_type);
free_pipe_list(command->group);
debug_printf_clean(" end group\n");
//command->group = NULL;
}
/* else is crucial here.
* If group != NULL, child_func is meaningless */
#if ENABLE_HUSH_FUNCTIONS
else if (command->child_func) {
debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
command->child_func->parent_cmd = NULL;
}
#endif
#if !BB_MMU
free(command->group_as_string);
//command->group_as_string = NULL;
#endif
for (r = command->redirects; r; r = rnext) {
debug_printf_clean(" redirect %d%s",
r->rd_fd, redir_table[r->rd_type].descrip);
/* guard against the case >$FOO, where foo is unset or blank */
if (r->rd_filename) {
debug_printf_clean(" fname:'%s'\n", r->rd_filename);
free(r->rd_filename);
//r->rd_filename = NULL;
}
debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
rnext = r->next;
free(r);
}
//command->redirects = NULL;
}
free(pi->cmds); /* children are an array, they get freed all at once */
//pi->cmds = NULL;
#if ENABLE_HUSH_JOB
free(pi->cmdtext);
//pi->cmdtext = NULL;
#endif
next = pi->next;
free(pi);
return next;
}
static void free_pipe_list(struct pipe *pi)
{
while (pi) {
#if HAS_KEYWORDS
debug_printf_clean("pipe reserved word %d\n", pi->res_word);
#endif
debug_printf_clean("pipe followup code %d\n", pi->followup);
pi = free_pipe(pi);
}
}
/*** Parsing routines ***/
#ifndef debug_print_tree
static void debug_print_tree(struct pipe *pi, int lvl)
{
static const char *const PIPE[] = {
[PIPE_SEQ] = "SEQ",
[PIPE_AND] = "AND",
[PIPE_OR ] = "OR" ,
[PIPE_BG ] = "BG" ,
};
static const char *RES[] = {
[RES_NONE ] = "NONE" ,
# if ENABLE_HUSH_IF
[RES_IF ] = "IF" ,
[RES_THEN ] = "THEN" ,
[RES_ELIF ] = "ELIF" ,
[RES_ELSE ] = "ELSE" ,
[RES_FI ] = "FI" ,
# endif
# if ENABLE_HUSH_LOOPS
[RES_FOR ] = "FOR" ,
[RES_WHILE] = "WHILE",
[RES_UNTIL] = "UNTIL",
[RES_DO ] = "DO" ,
[RES_DONE ] = "DONE" ,
# endif
# if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
[RES_IN ] = "IN" ,
# endif
# if ENABLE_HUSH_CASE
[RES_CASE ] = "CASE" ,
[RES_CASE_IN ] = "CASE_IN" ,
[RES_MATCH] = "MATCH",
[RES_CASE_BODY] = "CASE_BODY",
[RES_ESAC ] = "ESAC" ,
# endif
[RES_XXXX ] = "XXXX" ,
[RES_SNTX ] = "SNTX" ,
};
static const char *const CMDTYPE[] = {
"{}",
"()",
"[noglob]",
# if ENABLE_HUSH_FUNCTIONS
"func()",
# endif
};
int pin, prn;
pin = 0;
while (pi) {
fdprintf(2, "%*spipe %d %sres_word=%s followup=%d %s\n",
lvl*2, "",
pin,
(IF_HAS_KEYWORDS(pi->pi_inverted ? "! " :) ""),
RES[pi->res_word],
pi->followup, PIPE[pi->followup]
);
prn = 0;
while (prn < pi->num_cmds) {
struct command *command = &pi->cmds[prn];
char **argv = command->argv;
fdprintf(2, "%*s cmd %d assignment_cnt:%d",
lvl*2, "", prn,
command->assignment_cnt);
#if ENABLE_HUSH_LINENO_VAR
fdprintf(2, " LINENO:%u", command->lineno);
#endif
if (command->group) {
fdprintf(2, " group %s: (argv=%p)%s%s\n",
CMDTYPE[command->cmd_type],
argv
# if !BB_MMU
, " group_as_string:", command->group_as_string
# else
, "", ""
# endif
);
debug_print_tree(command->group, lvl+1);
prn++;
continue;
}
if (argv) while (*argv) {
fdprintf(2, " '%s'", *argv);
argv++;
}
if (command->redirects)
fdprintf(2, " {redir}");
fdprintf(2, "\n");
prn++;
}
pi = pi->next;
pin++;
}
}
#endif /* debug_print_tree */
static struct pipe *new_pipe(void)
{
struct pipe *pi;
pi = xzalloc(sizeof(struct pipe));
/*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
return pi;
}
/* Command (member of a pipe) is complete, or we start a new pipe
* if ctx->command is NULL.
* No errors possible here.
*/
static int done_command(struct parse_context *ctx)
{
/* The command is really already in the pipe structure, so
* advance the pipe counter and make a new, null command. */
struct pipe *pi = ctx->pipe;
struct command *command = ctx->command;
#if 0 /* Instead we emit error message at run time */
if (ctx->pending_redirect) {
/* For example, "cmd >" (no filename to redirect to) */
syntax_error("invalid redirect");
ctx->pending_redirect = NULL;
}
#endif
if (command) {
if (IS_NULL_CMD(command)) {
debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
goto clear_and_ret;
}
pi->num_cmds++;
debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
//debug_print_tree(ctx->list_head, 20);
} else {
debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
}
/* Only real trickiness here is that the uncommitted
* command structure is not counted in pi->num_cmds. */
pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
ctx->command = command = &pi->cmds[pi->num_cmds];
clear_and_ret:
memset(command, 0, sizeof(*command));
#if ENABLE_HUSH_LINENO_VAR
command->lineno = G.lineno;
debug_printf_parse("command->lineno = G.lineno (%u)\n", G.lineno);
#endif
return pi->num_cmds; /* used only for 0/nonzero check */
}
static void done_pipe(struct parse_context *ctx, pipe_style type)
{
int not_null;
debug_printf_parse("done_pipe entered, followup %d\n", type);
/* Close previous command */
not_null = done_command(ctx);
#if HAS_KEYWORDS
ctx->pipe->pi_inverted = ctx->ctx_inverted;
ctx->ctx_inverted = 0;
ctx->pipe->res_word = ctx->ctx_res_w;
#endif
if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
/* Necessary since && and || have precedence over &:
* "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
* in a backgrounded subshell.
*/
struct pipe *pi;
struct command *command;
/* Is this actually this construct, all pipes end with && or ||? */
pi = ctx->list_head;
while (pi != ctx->pipe) {
if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
goto no_conv;
pi = pi->next;
}
debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
pi = xzalloc(sizeof(*pi));
pi->followup = PIPE_BG;
pi->num_cmds = 1;
pi->cmds = xzalloc(sizeof(pi->cmds[0]));
command = &pi->cmds[0];
if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
command->cmd_type = CMD_NORMAL;
command->group = ctx->list_head;
#if !BB_MMU
command->group_as_string = xstrndup(
ctx->as_string.data,
ctx->as_string.length - 1 /* do not copy last char, "&" */
);
#endif
/* Replace all pipes in ctx with one newly created */
ctx->list_head = ctx->pipe = pi;
} else {
no_conv:
ctx->pipe->followup = type;
}
/* Without this check, even just <enter> on command line generates
* tree of three NOPs (!). Which is harmless but annoying.
* IOW: it is safe to do it unconditionally. */
if (not_null
#if ENABLE_HUSH_IF
|| ctx->ctx_res_w == RES_FI
#endif
#if ENABLE_HUSH_LOOPS
|| ctx->ctx_res_w == RES_DONE
|| ctx->ctx_res_w == RES_FOR
|| ctx->ctx_res_w == RES_IN
#endif
#if ENABLE_HUSH_CASE
|| ctx->ctx_res_w == RES_ESAC
#endif
) {
struct pipe *new_p;
debug_printf_parse("done_pipe: adding new pipe: "
"not_null:%d ctx->ctx_res_w:%d\n",
not_null, ctx->ctx_res_w);
new_p = new_pipe();
ctx->pipe->next = new_p;
ctx->pipe = new_p;
/* RES_THEN, RES_DO etc are "sticky" -
* they remain set for pipes inside if/while.
* This is used to control execution.
* RES_FOR and RES_IN are NOT sticky (needed to support
* cases where variable or value happens to match a keyword):
*/
#if ENABLE_HUSH_LOOPS
if (ctx->ctx_res_w == RES_FOR
|| ctx->ctx_res_w == RES_IN)
ctx->ctx_res_w = RES_NONE;
#endif
#if ENABLE_HUSH_CASE
if (ctx->ctx_res_w == RES_MATCH)
ctx->ctx_res_w = RES_CASE_BODY;
if (ctx->ctx_res_w == RES_CASE)
ctx->ctx_res_w = RES_CASE_IN;
#endif
ctx->command = NULL; /* trick done_command below */
/* Create the memory for command, roughly:
* ctx->pipe->cmds = new struct command;
* ctx->command = &ctx->pipe->cmds[0];
*/
done_command(ctx);
//debug_print_tree(ctx->list_head, 10);
}
debug_printf_parse("done_pipe return\n");
}
static void initialize_context(struct parse_context *ctx)
{
memset(ctx, 0, sizeof(*ctx));
if (MAYBE_ASSIGNMENT != 0)
ctx->is_assignment = MAYBE_ASSIGNMENT;
ctx->pipe = ctx->list_head = new_pipe();
/* Create the memory for command, roughly:
* ctx->pipe->cmds = new struct command;
* ctx->command = &ctx->pipe->cmds[0];
*/
done_command(ctx);
}
/* If a reserved word is found and processed, parse context is modified
* and 1 is returned.
*/
#if HAS_KEYWORDS
struct reserved_combo {
char literal[6];
unsigned char res;
unsigned char assignment_flag;
int flag;
};
enum {
FLAG_END = (1 << RES_NONE ),
# if ENABLE_HUSH_IF
FLAG_IF = (1 << RES_IF ),
FLAG_THEN = (1 << RES_THEN ),
FLAG_ELIF = (1 << RES_ELIF ),
FLAG_ELSE = (1 << RES_ELSE ),
FLAG_FI = (1 << RES_FI ),
# endif
# if ENABLE_HUSH_LOOPS
FLAG_FOR = (1 << RES_FOR ),
FLAG_WHILE = (1 << RES_WHILE),
FLAG_UNTIL = (1 << RES_UNTIL),
FLAG_DO = (1 << RES_DO ),
FLAG_DONE = (1 << RES_DONE ),
FLAG_IN = (1 << RES_IN ),
# endif
# if ENABLE_HUSH_CASE
FLAG_MATCH = (1 << RES_MATCH),
FLAG_ESAC = (1 << RES_ESAC ),
# endif
FLAG_START = (1 << RES_XXXX ),
};
static const struct reserved_combo* match_reserved_word(o_string *word)
{
/* Mostly a list of accepted follow-up reserved words.
* FLAG_END means we are done with the sequence, and are ready
* to turn the compound list into a command.
* FLAG_START means the word must start a new compound list.
*/
static const struct reserved_combo reserved_list[] = {
# if ENABLE_HUSH_IF
{ "!", RES_NONE, NOT_ASSIGNMENT , 0 },
{ "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
{ "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
{ "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
{ "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
{ "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
# endif
# if ENABLE_HUSH_LOOPS
{ "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
{ "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
{ "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
{ "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
{ "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
{ "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
# endif
# if ENABLE_HUSH_CASE
{ "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
{ "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
# endif
};
const struct reserved_combo *r;
for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
if (strcmp(word->data, r->literal) == 0)
return r;
}
return NULL;
}
/* Return NULL: not a keyword, else: keyword
*/
static const struct reserved_combo* reserved_word(struct parse_context *ctx)
{
# if ENABLE_HUSH_CASE
static const struct reserved_combo reserved_match = {
"", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
};
# endif
const struct reserved_combo *r;
if (ctx->word.has_quoted_part)
return 0;
r = match_reserved_word(&ctx->word);
if (!r)
return r; /* NULL */
debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
# if ENABLE_HUSH_CASE
if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
/* "case word IN ..." - IN part starts first MATCH part */
r = &reserved_match;
} else
# endif
if (r->flag == 0) { /* '!' */
if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
syntax_error("! ! command");
ctx->ctx_res_w = RES_SNTX;
}
ctx->ctx_inverted = 1;
return r;
}
if (r->flag & FLAG_START) {
struct parse_context *old;
old = xmemdup(ctx, sizeof(*ctx));
debug_printf_parse("push stack %p\n", old);
initialize_context(ctx);
ctx->stack = old;
} else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
syntax_error_at(ctx->word.data);
ctx->ctx_res_w = RES_SNTX;
return r;
} else {
/* "{...} fi" is ok. "{...} if" is not
* Example:
* if { echo foo; } then { echo bar; } fi */
if (ctx->command->group)
done_pipe(ctx, PIPE_SEQ);
}
ctx->ctx_res_w = r->res;
ctx->old_flag = r->flag;
ctx->is_assignment = r->assignment_flag;
debug_printf_parse("ctx->is_assignment='%s'\n", assignment_flag[ctx->is_assignment]);
if (ctx->old_flag & FLAG_END) {
struct parse_context *old;
done_pipe(ctx, PIPE_SEQ);
debug_printf_parse("pop stack %p\n", ctx->stack);
old = ctx->stack;
old->command->group = ctx->list_head;
old->command->cmd_type = CMD_NORMAL;
# if !BB_MMU
/* At this point, the compound command's string is in
* ctx->as_string... except for the leading keyword!
* Consider this example: "echo a | if true; then echo a; fi"
* ctx->as_string will contain "true; then echo a; fi",
* with "if " remaining in old->as_string!
*/
{
char *str;
int len = old->as_string.length;
/* Concatenate halves */
o_addstr(&old->as_string, ctx->as_string.data);
o_free(&ctx->as_string);
/* Find where leading keyword starts in first half */
str = old->as_string.data + len;
if (str > old->as_string.data)
str--; /* skip whitespace after keyword */
while (str > old->as_string.data && isalpha(str[-1]))
str--;
/* Ugh, we're done with this horrid hack */
old->command->group_as_string = xstrdup(str);
debug_printf_parse("pop, remembering as:'%s'\n",
old->command->group_as_string);
}
# endif
*ctx = *old; /* physical copy */
free(old);
}
return r;
}
#endif /* HAS_KEYWORDS */
/* Word is complete, look at it and update parsing context.
* Normal return is 0. Syntax errors return 1.
* Note: on return, word is reset, but not o_free'd!
*/
static int done_word(struct parse_context *ctx)
{
struct command *command = ctx->command;
debug_printf_parse("done_word entered: '%s' %p\n", ctx->word.data, command);
if (ctx->word.length == 0 && !ctx->word.has_quoted_part) {
debug_printf_parse("done_word return 0: true null, ignored\n");
return 0;
}
if (ctx->pending_redirect) {
/* We do not glob in e.g. >*.tmp case. bash seems to glob here
* only if run as "bash", not "sh" */
/* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html
* "2.7 Redirection
* If the redirection operator is "<<" or "<<-", the word
* that follows the redirection operator shall be
* subjected to quote removal; it is unspecified whether
* any of the other expansions occur. For the other
* redirection operators, the word that follows the
* redirection operator shall be subjected to tilde
* expansion, parameter expansion, command substitution,
* arithmetic expansion, and quote removal.
* Pathname expansion shall not be performed
* on the word by a non-interactive shell; an interactive
* shell may perform it, but shall do so only when
* the expansion would result in one word."
*/
//bash does not do parameter/command substitution or arithmetic expansion
//for _heredoc_ redirection word: these constructs look for exact eof marker
// as written:
// <<EOF$t
// <<EOF$((1))
// <<EOF`true` [this case also makes heredoc "quoted", a-la <<"EOF". Probably bash-4.3.43 bug]
ctx->pending_redirect->rd_filename = xstrdup(ctx->word.data);
/* Cater for >\file case:
* >\a creates file a; >\\a, >"\a", >"\\a" create file \a
* Same with heredocs:
* for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
*/
if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
unbackslash(ctx->pending_redirect->rd_filename);
/* Is it <<"HEREDOC"? */
if (ctx->word.has_quoted_part) {
ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
}
}
debug_printf_parse("word stored in rd_filename: '%s'\n", ctx->word.data);
ctx->pending_redirect = NULL;
} else {
#if HAS_KEYWORDS
# if ENABLE_HUSH_CASE
if (ctx->ctx_dsemicolon
&& strcmp(ctx->word.data, "esac") != 0 /* not "... pattern) cmd;; esac" */
) {
/* already done when ctx_dsemicolon was set to 1: */
/* ctx->ctx_res_w = RES_MATCH; */
ctx->ctx_dsemicolon = 0;
} else
# endif
if (!command->argv /* if it's the first word... */
# if ENABLE_HUSH_LOOPS
&& ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
&& ctx->ctx_res_w != RES_IN
# endif
# if ENABLE_HUSH_CASE
&& ctx->ctx_res_w != RES_CASE
# endif
) {
const struct reserved_combo *reserved;
reserved = reserved_word(ctx);
debug_printf_parse("checking for reserved-ness: %d\n", !!reserved);
if (reserved) {
# if ENABLE_HUSH_LINENO_VAR
/* Case:
* "while ...; do
* cmd ..."
* If we don't close the pipe _now_, immediately after "do", lineno logic
* sees "cmd" as starting at "do" - i.e., at the previous line.
*/
if (0
IF_HUSH_IF(|| reserved->res == RES_THEN)
IF_HUSH_IF(|| reserved->res == RES_ELIF)
IF_HUSH_IF(|| reserved->res == RES_ELSE)
IF_HUSH_LOOPS(|| reserved->res == RES_DO)
) {
done_pipe(ctx, PIPE_SEQ);
}
# endif
o_reset_to_empty_unquoted(&ctx->word);
debug_printf_parse("done_word return %d\n",
(ctx->ctx_res_w == RES_SNTX));
return (ctx->ctx_res_w == RES_SNTX);
}
# if defined(CMD_SINGLEWORD_NOGLOB)
if (0
# if BASH_TEST2
|| strcmp(ctx->word.data, "[[") == 0
# endif
/* In bash, local/export/readonly are special, args
* are assignments and therefore expansion of them
* should be "one-word" expansion:
* $ export i=`echo 'a b'` # one arg: "i=a b"
* compare with:
* $ ls i=`echo 'a b'` # two args: "i=a" and "b"
* ls: cannot access i=a: No such file or directory
* ls: cannot access b: No such file or directory
* Note: bash 3.2.33(1) does this only if export word
* itself is not quoted:
* $ export i=`echo 'aaa bbb'`; echo "$i"
* aaa bbb
* $ "export" i=`echo 'aaa bbb'`; echo "$i"
* aaa
*/
IF_HUSH_LOCAL( || strcmp(ctx->word.data, "local") == 0)
IF_HUSH_EXPORT( || strcmp(ctx->word.data, "export") == 0)
IF_HUSH_READONLY(|| strcmp(ctx->word.data, "readonly") == 0)
) {
command->cmd_type = CMD_SINGLEWORD_NOGLOB;
}
/* fall through */
# endif
}
#endif /* HAS_KEYWORDS */
if (command->group) {
/* "{ echo foo; } echo bar" - bad */
syntax_error_at(ctx->word.data);
debug_printf_parse("done_word return 1: syntax error, "
"groups and arglists don't mix\n");
return 1;
}
/* If this word wasn't an assignment, next ones definitely
* can't be assignments. Even if they look like ones. */
if (ctx->is_assignment != DEFINITELY_ASSIGNMENT
&& ctx->is_assignment != WORD_IS_KEYWORD
) {
ctx->is_assignment = NOT_ASSIGNMENT;
} else {
if (ctx->is_assignment == DEFINITELY_ASSIGNMENT) {
command->assignment_cnt++;
debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
}
debug_printf_parse("ctx->is_assignment was:'%s'\n", assignment_flag[ctx->is_assignment]);
ctx->is_assignment = MAYBE_ASSIGNMENT;
}
debug_printf_parse("ctx->is_assignment='%s'\n", assignment_flag[ctx->is_assignment]);
command->argv = add_string_to_strings(command->argv, xstrdup(ctx->word.data));
debug_print_strings("word appended to argv", command->argv);
}
#if ENABLE_HUSH_LOOPS
if (ctx->ctx_res_w == RES_FOR) {
if (ctx->word.has_quoted_part
|| endofname(command->argv[0])[0] != '\0'
) {
/* bash says just "not a valid identifier" */
syntax_error("not a valid identifier in for");
return 1;
}
/* Force FOR to have just one word (variable name) */
/* NB: basically, this makes hush see "for v in ..."
* syntax as if it is "for v; in ...". FOR and IN become
* two pipe structs in parse tree. */
done_pipe(ctx, PIPE_SEQ);
}
#endif
#if ENABLE_HUSH_CASE
/* Force CASE to have just one word */
if (ctx->ctx_res_w == RES_CASE) {
done_pipe(ctx, PIPE_SEQ);
}
#endif
o_reset_to_empty_unquoted(&ctx->word);
debug_printf_parse("done_word return 0\n");
return 0;
}
/* Peek ahead in the input to find out if we have a "&n" construct,
* as in "2>&1", that represents duplicating a file descriptor.
* Return:
* REDIRFD_CLOSE if >&- "close fd" construct is seen,
* REDIRFD_SYNTAX_ERR if syntax error,
* REDIRFD_TO_FILE if no & was seen,
* or the number found.
*/
#if BB_MMU
#define parse_redir_right_fd(as_string, input) \
parse_redir_right_fd(input)
#endif
static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
{
int ch, d, ok;
ch = i_peek(input);
if (ch != '&')
return REDIRFD_TO_FILE;
ch = i_getch(input); /* get the & */
nommu_addchr(as_string, ch);
ch = i_peek(input);
if (ch == '-') {
ch = i_getch(input);
nommu_addchr(as_string, ch);
return REDIRFD_CLOSE;
}
d = 0;
ok = 0;
while (ch != EOF && isdigit(ch)) {
d = d*10 + (ch-'0');
ok = 1;
ch = i_getch(input);
nommu_addchr(as_string, ch);
ch = i_peek(input);
}
if (ok) return d;
//TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
bb_error_msg("ambiguous redirect");
return REDIRFD_SYNTAX_ERR;
}
/* Return code is 0 normal, 1 if a syntax error is detected
*/
static int parse_redirect(struct parse_context *ctx,
int fd,
redir_type style,
struct in_str *input)
{
struct command *command = ctx->command;
struct redir_struct *redir;
struct redir_struct **redirp;
int dup_num;
dup_num = REDIRFD_TO_FILE;
if (style != REDIRECT_HEREDOC) {
/* Check for a '>&1' type redirect */
dup_num = parse_redir_right_fd(&ctx->as_string, input);
if (dup_num == REDIRFD_SYNTAX_ERR)
return 1;
} else {
int ch = i_peek_and_eat_bkslash_nl(input);
dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
if (dup_num) { /* <<-... */
ch = i_getch(input);
nommu_addchr(&ctx->as_string, ch);
ch = i_peek(input);
}
}
if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
int ch = i_peek_and_eat_bkslash_nl(input);
if (ch == '|') {
/* >|FILE redirect ("clobbering" >).
* Since we do not support "set -o noclobber" yet,
* >| and > are the same for now. Just eat |.
*/
ch = i_getch(input);
nommu_addchr(&ctx->as_string, ch);
}
}
/* Create a new redir_struct and append it to the linked list */
redirp = &command->redirects;
while ((redir = *redirp) != NULL) {
redirp = &(redir->next);
}
*redirp = redir = xzalloc(sizeof(*redir));
/* redir->next = NULL; */
/* redir->rd_filename = NULL; */
redir->rd_type = style;
redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
redir_table[style].descrip);
redir->rd_dup = dup_num;
if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
/* Erik had a check here that the file descriptor in question
* is legit; I postpone that to "run time"
* A "-" representation of "close me" shows up as a -3 here */
debug_printf_parse("duplicating redirect '%d>&%d'\n",
redir->rd_fd, redir->rd_dup);
} else {
#if 0 /* Instead we emit error message at run time */
if (ctx->pending_redirect) {
/* For example, "cmd > <file" */
syntax_error("invalid redirect");
}
#endif
/* Set ctx->pending_redirect, so we know what to do at the
* end of the next parsed word. */
ctx->pending_redirect = redir;
}
return 0;
}
/* If a redirect is immediately preceded by a number, that number is
* supposed to tell which file descriptor to redirect. This routine
* looks for such preceding numbers. In an ideal world this routine
* needs to handle all the following classes of redirects...
* echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
* echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
* echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
* echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
*
* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
* "2.7 Redirection
* ... If n is quoted, the number shall not be recognized as part of
* the redirection expression. For example:
* echo \2>a
* writes the character 2 into file a"
* We are getting it right by setting ->has_quoted_part on any \<char>
*
* A -1 return means no valid number was found,
* the caller should use the appropriate default for this redirection.
*/
static int redirect_opt_num(o_string *o)
{
int num;
if (o->data == NULL)
return -1;
num = bb_strtou(o->data, NULL, 10);
if (errno || num < 0)
return -1;
o_reset_to_empty_unquoted(o);
return num;
}
#if BB_MMU
#define fetch_till_str(as_string, input, word, skip_tabs) \
fetch_till_str(input, word, skip_tabs)
#endif
static char *fetch_till_str(o_string *as_string,
struct in_str *input,
const char *word,
int heredoc_flags)
{
o_string heredoc = NULL_O_STRING;
unsigned past_EOL;
int prev = 0; /* not \ */
int ch;
/* Starting with "" is necessary for this case:
* cat <<EOF
*
* xxx
* EOF
*/
heredoc.data = xzalloc(1); /* start as "", not as NULL */
goto jump_in;
while (1) {
ch = i_getch(input);
if (ch != EOF)
nommu_addchr(as_string, ch);
if (ch == '\n' || ch == EOF) {
check_heredoc_end:
if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\') {
/* End-of-line, and not a line continuation */
if (strcmp(heredoc.data + past_EOL, word) == 0) {
heredoc.data[past_EOL] = '\0';
debug_printf_heredoc("parsed '%s' heredoc '%s'\n", word, heredoc.data);
return heredoc.data;
}
if (ch == '\n') {
/* This is a new line.
* Remember position and backslash-escaping status.
*/
o_addchr(&heredoc, ch);
prev = ch;
jump_in:
past_EOL = heredoc.length;
/* Get 1st char of next line, possibly skipping leading tabs */
do {
ch = i_getch(input);
if (ch != EOF)
nommu_addchr(as_string, ch);
} while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
/* If this immediately ended the line,
* go back to end-of-line checks.
*/
if (ch == '\n')
goto check_heredoc_end;
}
} else {
/* Backslash-line continuation in an unquoted
* heredoc. This does not need special handling
* for heredoc body (unquoted heredocs are
* expanded on "execution" and that would take
* care of this case too), but not the case
* of line continuation *in terminator*:
* cat <<EOF
* Ok1
* EO\
* F
*/
heredoc.data[--heredoc.length] = '\0';
prev = 0; /* not '\' */
continue;
}
}
if (ch == EOF) {
o_free(&heredoc);
return NULL; /* error */
}
o_addchr(&heredoc, ch);
nommu_addchr(as_string, ch);
if (prev == '\\' && ch == '\\')
/* Correctly handle foo\\<eol> (not a line cont.) */
prev = 0; /* not '\' */
else
prev = ch;
}
}
/* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
* and load them all. There should be exactly heredoc_cnt of them.
*/
#if BB_MMU
#define fetch_heredocs(as_string, pi, heredoc_cnt, input) \
fetch_heredocs(pi, heredoc_cnt, input)
#endif
static int fetch_heredocs(o_string *as_string, struct pipe *pi, int heredoc_cnt, struct in_str *input)
{
while (pi && heredoc_cnt) {
int i;
struct command *cmd = pi->cmds;
debug_printf_heredoc("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
pi->num_cmds,
cmd->argv ? cmd->argv[0] : "NONE"
);
for (i = 0; i < pi->num_cmds; i++) {
struct redir_struct *redir = cmd->redirects;
debug_printf_heredoc("fetch_heredocs: %d cmd argv0:'%s'\n",
i, cmd->argv ? cmd->argv[0] : "NONE");
while (redir) {
if (redir->rd_type == REDIRECT_HEREDOC) {
char *p;
redir->rd_type = REDIRECT_HEREDOC2;
/* redir->rd_dup is (ab)used to indicate <<- */
p = fetch_till_str(as_string, input,
redir->rd_filename, redir->rd_dup);
if (!p) {
syntax_error("unexpected EOF in here document");
return -1;
}
free(redir->rd_filename);
redir->rd_filename = p;
heredoc_cnt--;
}
redir = redir->next;
}
if (cmd->group) {
//bb_error_msg("%s:%u heredoc_cnt:%d", __func__, __LINE__, heredoc_cnt);
heredoc_cnt = fetch_heredocs(as_string, cmd->group, heredoc_cnt, input);
//bb_error_msg("%s:%u heredoc_cnt:%d", __func__, __LINE__, heredoc_cnt);
if (heredoc_cnt < 0)
return heredoc_cnt; /* error */
}
cmd++;
}
pi = pi->next;
}
return heredoc_cnt;
}
static int run_list(struct pipe *pi);
#if BB_MMU
#define parse_stream(pstring, heredoc_cnt_ptr, input, end_trigger) \
parse_stream(heredoc_cnt_ptr, input, end_trigger)
#endif
static struct pipe *parse_stream(char **pstring,
int *heredoc_cnt_ptr,
struct in_str *input,
int end_trigger);
/* Returns number of heredocs not yet consumed,
* or -1 on error.
*/
static int parse_group(struct parse_context *ctx,
struct in_str *input, int ch)
{
/* ctx->word contains characters seen prior to ( or {.
* Typically it's empty, but for function defs,
* it contains function name (without '()'). */
#if BB_MMU
# define as_string NULL
#else
char *as_string = NULL;
#endif
struct pipe *pipe_list;
int heredoc_cnt = 0;
int endch;
struct command *command = ctx->command;
debug_printf_parse("parse_group entered\n");
#if ENABLE_HUSH_FUNCTIONS
if (ch == '(' && !ctx->word.has_quoted_part) {
if (ctx->word.length)
if (done_word(ctx))
return -1;
if (!command->argv)
goto skip; /* (... */
if (command->argv[1]) { /* word word ... (... */
syntax_error_unexpected_ch('(');
return -1;
}
/* it is "word(..." or "word (..." */
do
ch = i_getch(input);
while (ch == ' ' || ch == '\t');
if (ch != ')') {
syntax_error_unexpected_ch(ch);
return -1;
}
nommu_addchr(&ctx->as_string, ch);
do
ch = i_getch(input);
while (ch == ' ' || ch == '\t' || ch == '\n');
if (ch != '{' && ch != '(') {
syntax_error_unexpected_ch(ch);
return -1;
}
nommu_addchr(&ctx->as_string, ch);
command->cmd_type = CMD_FUNCDEF;
goto skip;
}
#endif
#if 0 /* Prevented by caller */
if (command->argv /* word [word]{... */
|| ctx->word.length /* word{... */
|| ctx->word.has_quoted_part /* ""{... */
) {
syntax_error(NULL);
debug_printf_parse("parse_group return -1: "
"syntax error, groups and arglists don't mix\n");
return -1;
}
#endif
IF_HUSH_FUNCTIONS(skip:)
endch = '}';
if (ch == '(') {
endch = ')';
IF_HUSH_FUNCTIONS(if (command->cmd_type != CMD_FUNCDEF))
command->cmd_type = CMD_SUBSHELL;
} else {
/* bash does not allow "{echo...", requires whitespace */
ch = i_peek(input);
if (ch != ' ' && ch != '\t' && ch != '\n'
&& ch != '(' /* but "{(..." is allowed (without whitespace) */
) {
syntax_error_unexpected_ch(ch);
return -1;
}
if (ch != '(') {
ch = i_getch(input);
nommu_addchr(&ctx->as_string, ch);
}
}
debug_printf_heredoc("calling parse_stream, heredoc_cnt:%d\n", heredoc_cnt);
pipe_list = parse_stream(&as_string, &heredoc_cnt, input, endch);
debug_printf_heredoc("parse_stream returned: heredoc_cnt:%d\n", heredoc_cnt);
#if !BB_MMU
if (as_string)
o_addstr(&ctx->as_string, as_string);
#endif
/* empty ()/{} or parse error? */
if (!pipe_list || pipe_list == ERR_PTR) {
/* parse_stream already emitted error msg */
if (!BB_MMU)
free(as_string);
debug_printf_parse("parse_group return -1: "
"parse_stream returned %p\n", pipe_list);
return -1;
}
#if !BB_MMU
as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
command->group_as_string = as_string;
debug_printf_parse("end of group, remembering as:'%s'\n",
command->group_as_string);
#endif
#if ENABLE_HUSH_FUNCTIONS
/* Convert "f() (cmds)" to "f() {(cmds)}" */
if (command->cmd_type == CMD_FUNCDEF && endch == ')') {
struct command *cmd2;
cmd2 = xzalloc(sizeof(*cmd2));
cmd2->cmd_type = CMD_SUBSHELL;
cmd2->group = pipe_list;
# if !BB_MMU
//UNTESTED!
cmd2->group_as_string = command->group_as_string;
command->group_as_string = xasprintf("(%s)", command->group_as_string);
# endif
pipe_list = new_pipe();
pipe_list->cmds = cmd2;
pipe_list->num_cmds = 1;
}
#endif
command->group = pipe_list;
debug_printf_parse("parse_group return %d\n", heredoc_cnt);
return heredoc_cnt;
/* command remains "open", available for possible redirects */
#undef as_string
}
#if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
/* Subroutines for copying $(...) and `...` things */
/* '...' */
static int add_till_single_quote(o_string *dest, struct in_str *input)
{
while (1) {
int ch = i_getch(input);
if (ch == EOF) {
syntax_error_unterm_ch('\'');
return 0;
}
if (ch == '\'')
return 1;
o_addchr(dest, ch);
}
}
static int add_till_single_quote_dquoted(o_string *dest, struct in_str *input)
{
while (1) {
int ch = i_getch(input);
if (ch == EOF) {
syntax_error_unterm_ch('\'');
return 0;
}
if (ch == '\'')
return 1;
o_addqchr(dest, ch);
}
}
/* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
static int add_till_double_quote(o_string *dest, struct in_str *input)
{
while (1) {
int ch = i_getch(input);
if (ch == EOF) {
syntax_error_unterm_ch('"');
return 0;
}
if (ch == '"')
return 1;
if (ch == '\\') { /* \x. Copy both chars. */
o_addchr(dest, ch);
ch = i_getch(input);
}
o_addchr(dest, ch);
if (ch == '`') {
if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
return 0;
o_addchr(dest, ch);
continue;
}
//if (ch == '$') ...
}
}
/* Process `cmd` - copy contents until "`" is seen. Complicated by
* \` quoting.
* "Within the backquoted style of command substitution, backslash
* shall retain its literal meaning, except when followed by: '$', '`', or '\'.
* The search for the matching backquote shall be satisfied by the first
* backquote found without a preceding backslash; during this search,
* if a non-escaped backquote is encountered within a shell comment,
* a here-document, an embedded command substitution of the $(command)
* form, or a quoted string, undefined results occur. A single-quoted
* or double-quoted string that begins, but does not end, within the
* "`...`" sequence produces undefined results."
* Example Output
* echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
*/
static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
{
while (1) {
int ch = i_getch(input);
if (ch == '`')
return 1;
if (ch == '\\') {
/* \x. Copy both unless it is \`, \$, \\ and maybe \" */
ch = i_getch(input);
if (ch != '`'
&& ch != '$'
&& ch != '\\'
&& (!in_dquote || ch != '"')
) {
o_addchr(dest, '\\');
}
}
if (ch == EOF) {
syntax_error_unterm_ch('`');
return 0;
}
o_addchr(dest, ch);
}
}
/* Process $(cmd) - copy contents until ")" is seen. Complicated by
* quoting and nested ()s.
* "With the $(command) style of command substitution, all characters
* following the open parenthesis to the matching closing parenthesis
* constitute the command. Any valid shell script can be used for command,
* except a script consisting solely of redirections which produces
* unspecified results."
* Example Output
* echo $(echo '(TEST)' BEST) (TEST) BEST
* echo $(echo 'TEST)' BEST) TEST) BEST
* echo $(echo \(\(TEST\) BEST) ((TEST) BEST
*
* Also adapted to eat ${var%...} and $((...)) constructs, since ... part
* can contain arbitrary constructs, just like $(cmd).
* In bash compat mode, it needs to also be able to stop on ':' or '/'
* for ${var:N[:M]} and ${var/P[/R]} parsing.
*/
#define DOUBLE_CLOSE_CHAR_FLAG 0x80
static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
{
int ch;
char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
# if BASH_SUBSTR || BASH_PATTERN_SUBST
char end_char2 = end_ch >> 8;
# endif
end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
#if ENABLE_HUSH_INTERACTIVE
G.promptmode = 1; /* PS2 */
#endif
debug_printf_prompt("%s promptmode=%d\n", __func__, G.promptmode);
while (1) {
ch = i_getch(input);
if (ch == EOF) {
syntax_error_unterm_ch(end_ch);
return 0;
}
if (ch == end_ch
# if BASH_SUBSTR || BASH_PATTERN_SUBST
|| ch == end_char2
# endif
) {
if (!dbl)
break;
/* we look for closing )) of $((EXPR)) */
if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
i_getch(input); /* eat second ')' */
break;
}
}
o_addchr(dest, ch);
//bb_error_msg("%s:o_addchr('%c')", __func__, ch);
if (ch == '(' || ch == '{') {
ch = (ch == '(' ? ')' : '}');
if (!add_till_closing_bracket(dest, input, ch))
return 0;
o_addchr(dest, ch);
continue;
}
if (ch == '\'') {
if (!add_till_single_quote(dest, input))
return 0;
o_addchr(dest, ch);
continue;
}
if (ch == '"') {
if (!add_till_double_quote(dest, input))
return 0;
o_addchr(dest, ch);
continue;
}
if (ch == '`') {
if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
return 0;
o_addchr(dest, ch);
continue;
}
if (ch == '\\') {
/* \x. Copy verbatim. Important for \(, \) */
ch = i_getch(input);
if (ch == EOF) {
syntax_error_unterm_ch(end_ch);
return 0;
}
#if 0
if (ch == '\n') {
/* "backslash+newline", ignore both */
o_delchr(dest); /* undo insertion of '\' */
continue;
}
#endif
o_addchr(dest, ch);
//bb_error_msg("%s:o_addchr('%c') after '\\'", __func__, ch);
continue;
}
}
debug_printf_parse("%s return '%s' ch:'%c'\n", __func__, dest->data, ch);
return ch;
}
#endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
/* Return code: 0 for OK, 1 for syntax error */
#if BB_MMU
#define parse_dollar(as_string, dest, input, quote_mask) \
parse_dollar(dest, input, quote_mask)
#define as_string NULL
#endif
static int parse_dollar(o_string *as_string,
o_string *dest,
struct in_str *input, unsigned char quote_mask)
{
int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
if (isalpha(ch)) {
make_var:
ch = i_getch(input);
nommu_addchr(as_string, ch);
/*make_var1:*/
o_addchr(dest, SPECIAL_VAR_SYMBOL);
while (1) {
debug_printf_parse(": '%c'\n", ch);
o_addchr(dest, ch | quote_mask);
quote_mask = 0;
ch = i_peek_and_eat_bkslash_nl(input);
if (!isalnum(ch) && ch != '_') {
/* End of variable name reached */
break;
}
ch = i_getch(input);
nommu_addchr(as_string, ch);
}
o_addchr(dest, SPECIAL_VAR_SYMBOL);
} else if (isdigit(ch)) {
make_one_char_var:
ch = i_getch(input);
nommu_addchr(as_string, ch);
o_addchr(dest, SPECIAL_VAR_SYMBOL);
debug_printf_parse(": '%c'\n", ch);
o_addchr(dest, ch | quote_mask);
o_addchr(dest, SPECIAL_VAR_SYMBOL);
} else switch (ch) {
case '$': /* pid */
case '!': /* last bg pid */
case '?': /* last exit code */
case '#': /* number of args */
case '*': /* args */
case '@': /* args */
goto make_one_char_var;
case '{': {
char len_single_ch;
o_addchr(dest, SPECIAL_VAR_SYMBOL);
ch = i_getch(input); /* eat '{' */
nommu_addchr(as_string, ch);
ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
/* It should be ${?}, or ${#var},
* or even ${?+subst} - operator acting on a special variable,
* or the beginning of variable name.
*/
if (ch == EOF
|| (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
) {
bad_dollar_syntax:
syntax_error_unterm_str("${name}");
debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
return 0;
}
nommu_addchr(as_string, ch);
len_single_ch = ch;
ch |= quote_mask;
/* It's possible to just call add_till_closing_bracket() at this point.
* However, this regresses some of our testsuite cases
* which check invalid constructs like ${%}.
* Oh well... let's check that the var name part is fine... */
while (1) {
unsigned pos;
o_addchr(dest, ch);
debug_printf_parse(": '%c'\n", ch);
ch = i_getch(input);
nommu_addchr(as_string, ch);
if (ch == '}')
break;
if (!isalnum(ch) && ch != '_') {
unsigned end_ch;
unsigned char last_ch;
/* handle parameter expansions
* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
*/
if (!strchr(VAR_SUBST_OPS, ch)) { /* ${var<bad_char>... */
if (len_single_ch != '#'
/*|| !strchr(SPECIAL_VARS_STR, ch) - disallow errors like ${#+} ? */
|| i_peek(input) != '}'
) {
goto bad_dollar_syntax;
}
/* else: it's "length of C" ${#C} op,
* where C is a single char
* special var name, e.g. ${#!}.
*/
}
/* Eat everything until closing '}' (or ':') */
end_ch = '}';
if (BASH_SUBSTR
&& ch == ':'
&& !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
) {
/* It's ${var:N[:M]} thing */
end_ch = '}' * 0x100 + ':';
}
if (BASH_PATTERN_SUBST
&& ch == '/'
) {
/* It's ${var/[/]pattern[/repl]} thing */
if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
i_getch(input);
nommu_addchr(as_string, '/');
ch = '\\';
}
end_ch = '}' * 0x100 + '/';
}
o_addchr(dest, ch);
/* The pattern can't be empty.
* IOW: if the first char after "${v//" is a slash,
* it does not terminate the pattern - it's the first char of the pattern:
* v=/dev/ram; echo ${v////-} prints -dev-ram (pattern is "/")
* v=/dev/ram; echo ${v///r/-} prints /dev-am (pattern is "/r")
*/
if (i_peek(input) == '/') {
o_addchr(dest, i_getch(input));
}
again:
if (!BB_MMU)
pos = dest->length;
#if ENABLE_HUSH_DOLLAR_OPS
last_ch = add_till_closing_bracket(dest, input, end_ch);
if (last_ch == 0) /* error? */
return 0;
#else
#error Simple code to only allow ${var} is not implemented
#endif
if (as_string) {
o_addstr(as_string, dest->data + pos);
o_addchr(as_string, last_ch);
}
if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
&& (end_ch & 0xff00)
) {
/* close the first block: */
o_addchr(dest, SPECIAL_VAR_SYMBOL);
/* while parsing N from ${var:N[:M]}
* or pattern from ${var/[/]pattern[/repl]} */
if ((end_ch & 0xff) == last_ch) {
/* got ':' or '/'- parse the rest */
end_ch = '}';
goto again;
}
/* got '}' */
if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
/* it's ${var:N} - emulate :999999999 */
o_addstr(dest, "999999999");
} /* else: it's ${var/[/]pattern} */
}
break;
}
len_single_ch = 0; /* it can't be ${#C} op */
}
o_addchr(dest, SPECIAL_VAR_SYMBOL);
break;
}
#if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
case '(': {
unsigned pos;
ch = i_getch(input);
nommu_addchr(as_string, ch);
# if ENABLE_FEATURE_SH_MATH
if (i_peek_and_eat_bkslash_nl(input) == '(') {
ch = i_getch(input);
nommu_addchr(as_string, ch);
o_addchr(dest, SPECIAL_VAR_SYMBOL);
o_addchr(dest, /*quote_mask |*/ '+');
if (!BB_MMU)
pos = dest->length;
if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
return 0; /* error */
if (as_string) {
o_addstr(as_string, dest->data + pos);
o_addchr(as_string, ')');
o_addchr(as_string, ')');
}
o_addchr(dest, SPECIAL_VAR_SYMBOL);
break;
}
# endif
# if ENABLE_HUSH_TICK
o_addchr(dest, SPECIAL_VAR_SYMBOL);
o_addchr(dest, quote_mask | '`');
if (!BB_MMU)
pos = dest->length;
if (!add_till_closing_bracket(dest, input, ')'))
return 0; /* error */
if (as_string) {
o_addstr(as_string, dest->data + pos);
o_addchr(as_string, ')');
}
o_addchr(dest, SPECIAL_VAR_SYMBOL);
# endif
break;
}
#endif
case '_':
goto make_var;
#if 0
/* TODO: $_ and $-: */
/* $_ Shell or shell script name; or last argument of last command
* (if last command wasn't a pipe; if it was, bash sets $_ to "");
* but in command's env, set to full pathname used to invoke it */
/* $- Option flags set by set builtin or shell options (-i etc) */
ch = i_getch(input);
nommu_addchr(as_string, ch);
ch = i_peek_and_eat_bkslash_nl(input);
if (isalnum(ch)) { /* it's $_name or $_123 */
ch = '_';
goto make_var1;
}
/* else: it's $_ */
#endif
default:
o_addQchr(dest, '$');
}
debug_printf_parse("parse_dollar return 1 (ok)\n");
return 1;
#undef as_string
}
#if BB_MMU
#define encode_string(as_string, dest, input, dquote_end) \
encode_string(dest, input, dquote_end)
#define as_string NULL
#endif
static int encode_string(o_string *as_string,
o_string *dest,
struct in_str *input,
int dquote_end)
{
int ch;
int next;
again:
ch = i_getch(input);
if (ch != EOF)
nommu_addchr(as_string, ch);
if (ch == dquote_end) { /* may be only '"' or EOF */
debug_printf_parse("encode_string return 1 (ok)\n");
return 1;
}
/* note: can't move it above ch == dquote_end check! */
if (ch == EOF) {
syntax_error_unterm_ch('"');
return 0; /* error */
}
next = '\0';
if (ch != '\n') {
next = i_peek(input);
}
debug_printf_parse("\" ch=%c (%d) escape=%d\n",
ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
if (ch == '\\') {
if (next == EOF) {
/* Testcase: in interactive shell a file with
* echo "unterminated string\<eof>
* is sourced.
*/
syntax_error_unterm_ch('"');
return 0; /* error */
}
/* bash:
* "The backslash retains its special meaning [in "..."]
* only when followed by one of the following characters:
* $, `, ", \, or <newline>. A double quote may be quoted
* within double quotes by preceding it with a backslash."
* NB: in (unquoted) heredoc, above does not apply to ",
* therefore we check for it by "next == dquote_end" cond.
*/
if (next == dquote_end || strchr("$`\\\n", next)) {
ch = i_getch(input); /* eat next */
if (ch == '\n')
goto again; /* skip \<newline> */
} /* else: ch remains == '\\', and we double it below: */
o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
nommu_addchr(as_string, ch);
goto again;
}
if (ch == '$') {
if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
debug_printf_parse("encode_string return 0: "
"parse_dollar returned 0 (error)\n");
return 0;
}
goto again;
}
#if ENABLE_HUSH_TICK
if (ch == '`') {
//unsigned pos = dest->length;
o_addchr(dest, SPECIAL_VAR_SYMBOL);
o_addchr(dest, 0x80 | '`');
if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
return 0; /* error */
o_addchr(dest, SPECIAL_VAR_SYMBOL);
//debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
goto again;
}
#endif
o_addQchr(dest, ch);
goto again;
#undef as_string
}
/*
* Scan input until EOF or end_trigger char.
* Return a list of pipes to execute, or NULL on EOF
* or if end_trigger character is met.
* On syntax error, exit if shell is not interactive,
* reset parsing machinery and start parsing anew,
* or return ERR_PTR.
*/
static struct pipe *parse_stream(char **pstring,
int *heredoc_cnt_ptr,
struct in_str *input,
int end_trigger)
{
struct parse_context ctx;
int heredoc_cnt;
/* Single-quote triggers a bypass of the main loop until its mate is
* found. When recursing, quote state is passed in via ctx.word.o_expflags.
*/
debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
end_trigger ? end_trigger : 'X');
debug_enter();
initialize_context(&ctx);
/* If very first arg is "" or '', ctx.word.data may end up NULL.
* Preventing this:
*/
ctx.word.data = xzalloc(1); /* start as "", not as NULL */
/* We used to separate words on $IFS here. This was wrong.
* $IFS is used only for word splitting when $var is expanded,
* here we should use blank chars as separators, not $IFS
*/
heredoc_cnt = 0;
while (1) {
const char *is_blank;
const char *is_special;
int ch;
int next;
int redir_fd;
redir_type redir_style;
ch = i_getch(input);
debug_printf_parse(": ch=%c (%d) escape=%d\n",
ch, ch, !!(ctx.word.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
if (ch == EOF) {
struct pipe *pi;
if (heredoc_cnt) {
syntax_error_unterm_str("here document");
goto parse_error;
}
if (end_trigger == ')') {
syntax_error_unterm_ch('(');
goto parse_error;
}
if (end_trigger == '}') {
syntax_error_unterm_ch('{');
goto parse_error;
}
if (done_word(&ctx)) {
goto parse_error;
}
o_free_and_set_NULL(&ctx.word);
done_pipe(&ctx, PIPE_SEQ);
pi = ctx.list_head;
/* If we got nothing... */
/* (this makes bare "&" cmd a no-op.
* bash says: "syntax error near unexpected token '&'") */
if (pi->num_cmds == 0
IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
) {
free_pipe_list(pi);
pi = NULL;
}
#if !BB_MMU
debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
if (pstring)
*pstring = ctx.as_string.data;
else
o_free(&ctx.as_string);
#endif
// heredoc_cnt must be 0 here anyway
//if (heredoc_cnt_ptr)
// *heredoc_cnt_ptr = heredoc_cnt;
debug_leave();
debug_printf_heredoc("parse_stream return heredoc_cnt:%d\n", heredoc_cnt);
debug_printf_parse("parse_stream return %p\n", pi);
return pi;
}
/* Handle "'" and "\" first, as they won't play nice with
* i_peek_and_eat_bkslash_nl() anyway:
* echo z\\
* and
* echo '\
* '
* would break.
*/
if (ch == '\\') {
ch = i_getch(input);
if (ch == '\n')
continue; /* drop \<newline>, get next char */
nommu_addchr(&ctx.as_string, '\\');
o_addchr(&ctx.word, '\\');
if (ch == EOF) {
/* Testcase: eval 'echo Ok\' */
/* bash-4.3.43 was removing backslash,
* but 4.4.19 retains it, most other shells too
*/
continue; /* get next char */
}
/* Example: echo Hello \2>file
* we need to know that word 2 is quoted
*/
ctx.word.has_quoted_part = 1;
nommu_addchr(&ctx.as_string, ch);
o_addchr(&ctx.word, ch);
continue; /* get next char */
}
nommu_addchr(&ctx.as_string, ch);
if (ch == '\'') {
ctx.word.has_quoted_part = 1;
next = i_getch(input);
if (next == '\'' && !ctx.pending_redirect)
goto insert_empty_quoted_str_marker;
ch = next;
while (1) {
if (ch == EOF) {
syntax_error_unterm_ch('\'');
goto parse_error;
}
nommu_addchr(&ctx.as_string, ch);
if (ch == '\'')
break;
if (ch == SPECIAL_VAR_SYMBOL) {
/* Convert raw ^C to corresponding special variable reference */
o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL);
o_addchr(&ctx.word, SPECIAL_VAR_QUOTED_SVS);
}
o_addqchr(&ctx.word, ch);
ch = i_getch(input);
}
continue; /* get next char */
}
next = '\0';
if (ch != '\n')
next = i_peek_and_eat_bkslash_nl(input);
is_special = "{}<>;&|()#" /* special outside of "str" */
"$\"" IF_HUSH_TICK("`") /* always special */
SPECIAL_VAR_SYMBOL_STR;
/* Are { and } special here? */
if (ctx.command->argv /* word [word]{... - non-special */
|| ctx.word.length /* word{... - non-special */
|| ctx.word.has_quoted_part /* ""{... - non-special */
|| (next != ';' /* }; - special */
&& next != ')' /* }) - special */
&& next != '(' /* {( - special */
&& next != '&' /* }& and }&& ... - special */
&& next != '|' /* }|| ... - special */
&& !strchr(defifs, next) /* {word - non-special */
)
) {
/* They are not special, skip "{}" */
is_special += 2;
}
is_special = strchr(is_special, ch);
is_blank = strchr(defifs, ch);
if (!is_special && !is_blank) { /* ordinary char */
ordinary_char:
o_addQchr(&ctx.word, ch);
if ((ctx.is_assignment == MAYBE_ASSIGNMENT
|| ctx.is_assignment == WORD_IS_KEYWORD)
&& ch == '='
&& endofname(ctx.word.data)[0] == '='
) {
ctx.is_assignment = DEFINITELY_ASSIGNMENT;
debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]);
}
continue;
}
if (is_blank) {
#if ENABLE_HUSH_LINENO_VAR
/* Case:
* "while ...; do<whitespace><newline>
* cmd ..."
* would think that "cmd" starts in <whitespace> -
* i.e., at the previous line.
* We need to skip all whitespace before newlines.
*/
while (ch != '\n') {
next = i_peek(input);
if (next != ' ' && next != '\t' && next != '\n')
break; /* next char is not ws */
ch = i_getch(input);
}
/* ch == last eaten whitespace char */
#endif
if (done_word(&ctx)) {
goto parse_error;
}
if (ch == '\n') {
/* Is this a case when newline is simply ignored?
* Some examples:
* "cmd | <newline> cmd ..."
* "case ... in <newline> word) ..."
*/
if (IS_NULL_CMD(ctx.command)
&& ctx.word.length == 0
&& !ctx.word.has_quoted_part
&& heredoc_cnt == 0
) {
/* This newline can be ignored. But...
* Without check #1, interactive shell
* ignores even bare <newline>,
* and shows the continuation prompt:
* ps1_prompt$ <enter>
* ps2> _ <=== wrong, should be ps1
* Without check #2, "cmd & <newline>"
* is similarly mistreated.
* (BTW, this makes "cmd & cmd"
* and "cmd && cmd" non-orthogonal.
* Really, ask yourself, why
* "cmd && <newline>" doesn't start
* cmd but waits for more input?
* The only reason is that it might be
* a "cmd1 && <nl> cmd2 &" construct,
* cmd1 may need to run in BG).
*/
struct pipe *pi = ctx.list_head;
if (pi->num_cmds != 0 /* check #1 */
&& pi->followup != PIPE_BG /* check #2 */
) {
continue;
}
}
/* Treat newline as a command separator. */
done_pipe(&ctx, PIPE_SEQ);
debug_printf_heredoc("heredoc_cnt:%d\n", heredoc_cnt);
if (heredoc_cnt) {
heredoc_cnt = fetch_heredocs(&ctx.as_string, ctx.list_head, heredoc_cnt, input);
if (heredoc_cnt != 0)
goto parse_error;
}
ctx.is_assignment = MAYBE_ASSIGNMENT;
debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]);
ch = ';';
/* note: if (is_blank) continue;
* will still trigger for us */
}
}
/* "cmd}" or "cmd }..." without semicolon or &:
* } is an ordinary char in this case, even inside { cmd; }
* Pathological example: { ""}; } should exec "}" cmd
*/
if (ch == '}') {
if (ctx.word.length != 0 /* word} */
|| ctx.word.has_quoted_part /* ""} */
) {
goto ordinary_char;
}
if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
/* Generally, there should be semicolon: "cmd; }"
* However, bash allows to omit it if "cmd" is
* a group. Examples:
* { { echo 1; } }
* {(echo 1)}
* { echo 0 >&2 | { echo 1; } }
* { while false; do :; done }
* { case a in b) ;; esac }
*/
if (ctx.command->group)
goto term_group;
goto ordinary_char;
}
if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
/* Can't be an end of {cmd}, skip the check */
goto skip_end_trigger;
/* else: } does terminate a group */
}
term_group:
if (end_trigger && end_trigger == ch
&& (ch != ';' || heredoc_cnt == 0)
#if ENABLE_HUSH_CASE
&& (ch != ')'
|| ctx.ctx_res_w != RES_MATCH
|| (!ctx.word.has_quoted_part && strcmp(ctx.word.data, "esac") == 0)
)
#endif
) {
if (done_word(&ctx)) {
goto parse_error;
}
done_pipe(&ctx, PIPE_SEQ);
ctx.is_assignment = MAYBE_ASSIGNMENT;
debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]);
/* Do we sit outside of any if's, loops or case's? */
if (!HAS_KEYWORDS
IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
) {
o_free_and_set_NULL(&ctx.word);
#if !BB_MMU
debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
if (pstring)
*pstring = ctx.as_string.data;
else
o_free(&ctx.as_string);
#endif
if (ch != ';' && IS_NULL_PIPE(ctx.list_head)) {
/* Example: bare "{ }", "()" */
G.last_exitcode = 2; /* bash compat */
syntax_error_unexpected_ch(ch);
goto parse_error2;
}
if (heredoc_cnt_ptr)
*heredoc_cnt_ptr = heredoc_cnt;
debug_printf_heredoc("parse_stream return heredoc_cnt:%d\n", heredoc_cnt);
debug_printf_parse("parse_stream return %p: "
"end_trigger char found\n",
ctx.list_head);
debug_leave();
return ctx.list_head;
}
}
if (is_blank)
continue;
/* Catch <, > before deciding whether this word is
* an assignment. a=1 2>z b=2: b=2 is still assignment */
switch (ch) {
case '>':
redir_fd = redirect_opt_num(&ctx.word);
if (done_word(&ctx)) {
goto parse_error;
}
redir_style = REDIRECT_OVERWRITE;
if (next == '>') {
redir_style = REDIRECT_APPEND;
ch = i_getch(input);
nommu_addchr(&ctx.as_string, ch);
}
#if 0
else if (next == '(') {
syntax_error(">(process) not supported");
goto parse_error;
}
#endif
if (parse_redirect(&ctx, redir_fd, redir_style, input))
goto parse_error;
continue; /* get next char */
case '<':
redir_fd = redirect_opt_num(&ctx.word);
if (done_word(&ctx)) {
goto parse_error;
}
redir_style = REDIRECT_INPUT;
if (next == '<') {
redir_style = REDIRECT_HEREDOC;
heredoc_cnt++;
debug_printf_heredoc("++heredoc_cnt=%d\n", heredoc_cnt);
ch = i_getch(input);
nommu_addchr(&ctx.as_string, ch);
} else if (next == '>') {
redir_style = REDIRECT_IO;
ch = i_getch(input);
nommu_addchr(&ctx.as_string, ch);
}
#if 0
else if (next == '(') {
syntax_error("<(process) not supported");
goto parse_error;
}
#endif
if (parse_redirect(&ctx, redir_fd, redir_style, input))
goto parse_error;
continue; /* get next char */
case '#':
if (ctx.word.length == 0 && !ctx.word.has_quoted_part) {
/* skip "#comment" */
/* note: we do not add it to &ctx.as_string */
/* TODO: in bash:
* comment inside $() goes to the next \n, even inside quoted string (!):
* cmd "$(cmd2 #comment)" - syntax error
* cmd "`cmd2 #comment`" - ok
* We accept both (comment ends where command subst ends, in both cases).
*/
while (1) {
ch = i_peek(input);
if (ch == '\n') {
nommu_addchr(&ctx.as_string, '\n');
break;
}
ch = i_getch(input);
if (ch == EOF)
break;
}
continue; /* get next char */
}
break;
}
skip_end_trigger:
if (ctx.is_assignment == MAYBE_ASSIGNMENT
/* check that we are not in word in "a=1 2>word b=1": */
&& !ctx.pending_redirect
) {
/* ch is a special char and thus this word
* cannot be an assignment */
ctx.is_assignment = NOT_ASSIGNMENT;
debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]);
}
/* Note: nommu_addchr(&ctx.as_string, ch) is already done */
switch (ch) {
case SPECIAL_VAR_SYMBOL:
/* Convert raw ^C to corresponding special variable reference */
o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL);
o_addchr(&ctx.word, SPECIAL_VAR_QUOTED_SVS);
/* fall through */
case '#':
/* non-comment #: "echo a#b" etc */
o_addchr(&ctx.word, ch);
continue; /* get next char */
case '$':
if (!parse_dollar(&ctx.as_string, &ctx.word, input, /*quote_mask:*/ 0)) {
debug_printf_parse("parse_stream parse error: "
"parse_dollar returned 0 (error)\n");
goto parse_error;
}
continue; /* get next char */
case '"':
ctx.word.has_quoted_part = 1;
if (next == '"' && !ctx.pending_redirect) {
i_getch(input); /* eat second " */
insert_empty_quoted_str_marker:
nommu_addchr(&ctx.as_string, next);
o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL);
o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL);
continue; /* get next char */
}
if (ctx.is_assignment == NOT_ASSIGNMENT)
ctx.word.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
if (!encode_string(&ctx.as_string, &ctx.word, input, '"'))
goto parse_error;
ctx.word.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
continue; /* get next char */
#if ENABLE_HUSH_TICK
case '`': {
USE_FOR_NOMMU(unsigned pos;)
o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL);
o_addchr(&ctx.word, '`');
USE_FOR_NOMMU(pos = ctx.word.length;)
if (!add_till_backquote(&ctx.word, input, /*in_dquote:*/ 0))
goto parse_error;
# if !BB_MMU
o_addstr(&ctx.as_string, ctx.word.data + pos);
o_addchr(&ctx.as_string, '`');
# endif
o_addchr(&ctx.word, SPECIAL_VAR_SYMBOL);
//debug_printf_subst("SUBST RES3 '%s'\n", ctx.word.data + pos);
continue; /* get next char */
}
#endif
case ';':
#if ENABLE_HUSH_CASE
case_semi:
#endif
if (done_word(&ctx)) {
goto parse_error;
}
done_pipe(&ctx, PIPE_SEQ);
#if ENABLE_HUSH_CASE
/* Eat multiple semicolons, detect
* whether it means something special */
while (1) {
ch = i_peek_and_eat_bkslash_nl(input);
if (ch != ';')
break;
ch = i_getch(input);
nommu_addchr(&ctx.as_string, ch);
if (ctx.ctx_res_w == RES_CASE_BODY) {
ctx.ctx_dsemicolon = 1;
ctx.ctx_res_w = RES_MATCH;
break;
}
}
#endif
new_cmd:
/* We just finished a cmd. New one may start
* with an assignment */
ctx.is_assignment = MAYBE_ASSIGNMENT;
debug_printf_parse("ctx.is_assignment='%s'\n", assignment_flag[ctx.is_assignment]);
continue; /* get next char */
case '&':
if (done_word(&ctx)) {
goto parse_error;
}
if (next == '&') {
ch = i_getch(input);
nommu_addchr(&ctx.as_string, ch);
done_pipe(&ctx, PIPE_AND);
} else {
done_pipe(&ctx, PIPE_BG);
}
goto new_cmd;
case '|':
if (done_word(&ctx)) {
goto parse_error;
}
#if ENABLE_HUSH_CASE
if (ctx.ctx_res_w == RES_MATCH)
break; /* we are in case's "word | word)" */
#endif
if (next == '|') { /* || */
ch = i_getch(input);
nommu_addchr(&ctx.as_string, ch);
done_pipe(&ctx, PIPE_OR);
} else {
/* we could pick up a file descriptor choice here
* with redirect_opt_num(), but bash doesn't do it.
* "echo foo 2| cat" yields "foo 2". */
done_command(&ctx);
}
goto new_cmd;
case '(':
#if ENABLE_HUSH_CASE
/* "case... in [(]word)..." - skip '(' */
if (ctx.ctx_res_w == RES_MATCH
&& ctx.command->argv == NULL /* not (word|(... */
&& ctx.word.length == 0 /* not word(... */
&& ctx.word.has_quoted_part == 0 /* not ""(... */
) {
continue; /* get next char */
}
#endif
/* fall through */
case '{': {
int n = parse_group(&ctx, input, ch);
if (n < 0) {
goto parse_error;
}
debug_printf_heredoc("parse_group done, needs heredocs:%d\n", n);
heredoc_cnt += n;
goto new_cmd;
}
case ')':
#if ENABLE_HUSH_CASE
if (ctx.ctx_res_w == RES_MATCH)
goto case_semi;
#endif
case '}':
/* proper use of this character is caught by end_trigger:
* if we see {, we call parse_group(..., end_trigger='}')
* and it will match } earlier (not here). */
G.last_exitcode = 2;
syntax_error_unexpected_ch(ch);
goto parse_error2;
default:
if (HUSH_DEBUG)
bb_error_msg_and_die("BUG: unexpected %c", ch);
}
} /* while (1) */
parse_error:
G.last_exitcode = 1;
parse_error2:
{
struct parse_context *pctx;
IF_HAS_KEYWORDS(struct parse_context *p2;)
/* Clean up allocated tree.
* Sample for finding leaks on syntax error recovery path.
* Run it from interactive shell, watch pmap `pidof hush`.
* while if false; then false; fi; do break; fi
* Samples to catch leaks at execution:
* while if (true | { true;}); then echo ok; fi; do break; done
* while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
*/
pctx = &ctx;
do {
/* Update pipe/command counts,
* otherwise freeing may miss some */
done_pipe(pctx, PIPE_SEQ);
debug_printf_clean("freeing list %p from ctx %p\n",
pctx->list_head, pctx);
debug_print_tree(pctx->list_head, 0);
free_pipe_list(pctx->list_head);
debug_printf_clean("freed list %p\n", pctx->list_head);
#if !BB_MMU
o_free(&pctx->as_string);
#endif
IF_HAS_KEYWORDS(p2 = pctx->stack;)
if (pctx != &ctx) {
free(pctx);
}
IF_HAS_KEYWORDS(pctx = p2;)
} while (HAS_KEYWORDS && pctx);
o_free(&ctx.word);
#if !BB_MMU
if (pstring)
*pstring = NULL;
#endif
debug_leave();
return ERR_PTR;
}
}
/*** Execution routines ***/
/* Expansion can recurse, need forward decls: */
#if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
#define expand_string_to_string(str, EXP_flags, do_unbackslash) \
expand_string_to_string(str)
#endif
static char *expand_string_to_string(const char *str, int EXP_flags, int do_unbackslash);
#if ENABLE_HUSH_TICK
static int process_command_subs(o_string *dest, const char *s);
#endif
static int expand_vars_to_list(o_string *output, int n, char *arg);
/* expand_strvec_to_strvec() takes a list of strings, expands
* all variable references within and returns a pointer to
* a list of expanded strings, possibly with larger number
* of strings. (Think VAR="a b"; echo $VAR).
* This new list is allocated as a single malloc block.
* NULL-terminated list of char* pointers is at the beginning of it,
* followed by strings themselves.
* Caller can deallocate entire list by single free(list). */
/* A horde of its helpers come first: */
static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
{
while (--len >= 0) {
char c = *str++;
#if ENABLE_HUSH_BRACE_EXPANSION
if (c == '{' || c == '}') {
/* { -> \{, } -> \} */
o_addchr(o, '\\');
/* And now we want to add { or } and continue:
* o_addchr(o, c);
* continue;
* luckily, just falling through achieves this.
*/
}
#endif
o_addchr(o, c);
if (c == '\\') {
/* \z -> \\\z; \<eol> -> \\<eol> */
o_addchr(o, '\\');
if (len) {
len--;
o_addchr(o, '\\');
o_addchr(o, *str++);
}
}
}
}
/* Store given string, finalizing the word and starting new one whenever
* we encounter IFS char(s). This is used for expanding variable values.
* End-of-string does NOT finalize word: think about 'echo -$VAR-'.
* Return in output->ended_in_ifs:
* 1 - ended with IFS char, else 0 (this includes case of empty str).
*/
static int expand_on_ifs(o_string *output, int n, const char *str)
{
int last_is_ifs = 0;
while (1) {
int word_len;
if (!*str) /* EOL - do not finalize word */
break;
word_len = strcspn(str, G.ifs);
if (word_len) {
/* We have WORD_LEN leading non-IFS chars */
if (!(output->o_expflags & EXP_FLAG_GLOB)) {
o_addblock(output, str, word_len);
} else {
/* Protect backslashes against globbing up :)
* Example: "v='\*'; echo b$v" prints "b\*"
* (and does not try to glob on "*")
*/
o_addblock_duplicate_backslash(output, str, word_len);
/*/ Why can't we do it easier? */
/*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
/*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
}
last_is_ifs = 0;
str += word_len;
if (!*str) /* EOL - do not finalize word */
break;
}
/* We know str here points to at least one IFS char */
last_is_ifs = 1;
str += strspn(str, G.ifs_whitespace); /* skip IFS whitespace chars */
if (!*str) /* EOL - do not finalize word */
break;
if (G.ifs_whitespace != G.ifs /* usually false ($IFS is usually all whitespace), */
&& strchr(G.ifs, *str) /* the second check would fail */
) {
/* This is a non-whitespace $IFS char */
/* Skip it and IFS whitespace chars, start new word */
str++;
str += strspn(str, G.ifs_whitespace);
goto new_word;
}
/* Start new word... but not always! */
/* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
if (output->has_quoted_part
/*
* Case "v=' a'; echo $v":
* here nothing precedes the space in $v expansion,
* therefore we should not finish the word
* (IOW: if there *is* word to finalize, only then do it):
* It's okay if this accesses the byte before first argv[]:
* past call to o_save_ptr() cleared it to zero byte
* (grep for -prev-ifs-check-).
*/
|| output->data[output->length - 1]
) {
new_word:
o_addchr(output, '\0');
debug_print_list("expand_on_ifs", output, n);
n = o_save_ptr(output, n);
}
}
output->ended_in_ifs = last_is_ifs;
debug_print_list("expand_on_ifs[1]", output, n);
return n;
}
/* Helper to expand $((...)) and heredoc body. These act as if
* they are in double quotes, with the exception that they are not :).
* Just the rules are similar: "expand only $var and `cmd`"
*
* Returns malloced string.
* As an optimization, we return NULL if expansion is not needed.
*/
static char *encode_then_expand_string(const char *str)
{
char *exp_str;
struct in_str input;
o_string dest = NULL_O_STRING;
const char *cp;
cp = str;
for (;;) {
if (!*cp) return NULL; /* string has no special chars */
if (*cp == '$') break;
if (*cp == '\\') break;
#if ENABLE_HUSH_TICK
if (*cp == '`') break;
#endif
cp++;
}
/* We need to expand. Example:
* echo $(($a + `echo 1`)) $((1 + $((2)) ))
*/
setup_string_in_str(&input, str);
encode_string(NULL, &dest, &input, EOF);
//TODO: error check (encode_string returns 0 on error)?
//bb_error_msg("'%s' -> '%s'", str, dest.data);
exp_str = expand_string_to_string(dest.data,
EXP_FLAG_ESC_GLOB_CHARS,
/*unbackslash:*/ 1
);
//bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
o_free(&dest);
return exp_str;
}
static const char *first_special_char_in_vararg(const char *cp)
{
for (;;) {
if (!*cp) return NULL; /* string has no special chars */
if (*cp == '$') return cp;
if (*cp == '\\') return cp;
if (*cp == '\'') return cp;
if (*cp == '"') return cp;
#if ENABLE_HUSH_TICK
if (*cp == '`') return cp;
#endif
/* dquoted "${x:+ARG}" should not glob, therefore
* '*' et al require some non-literal processing: */
if (*cp == '*') return cp;
if (*cp == '?') return cp;
if (*cp == '[') return cp;
cp++;
}
}
/* Expanding ARG in ${var#ARG}, ${var%ARG}, or ${var/ARG/ARG}.
* These can contain single- and double-quoted strings,
* and treated as if the ARG string is initially unquoted. IOW:
* ${var#ARG} and "${var#ARG}" treat ARG the same (ARG can even be
* a dquoted string: "${var#"zz"}"), the difference only comes later
* (word splitting and globbing of the ${var...} result).
*/
#if !BASH_PATTERN_SUBST
#define encode_then_expand_vararg(str, handle_squotes, do_unbackslash) \
encode_then_expand_vararg(str, handle_squotes)
#endif
static char *encode_then_expand_vararg(const char *str, int handle_squotes, int do_unbackslash)
{
#if !BASH_PATTERN_SUBST && ENABLE_HUSH_CASE
const int do_unbackslash = 0;
#endif
char *exp_str;
struct in_str input;
o_string dest = NULL_O_STRING;
if (!first_special_char_in_vararg(str)) {
/* string has no special chars */
return NULL;
}
setup_string_in_str(&input, str);
dest.data = xzalloc(1); /* start as "", not as NULL */
exp_str = NULL;
for (;;) {
int ch;
ch = i_getch(&input);
debug_printf_parse("%s: ch=%c (%d) escape=%d\n",
__func__, ch, ch, !!dest.o_expflags);
if (!dest.o_expflags) {
if (ch == EOF)
break;
if (handle_squotes && ch == '\'') {
if (!add_till_single_quote_dquoted(&dest, &input))
goto ret; /* error */
continue;
}
}
if (ch == EOF) {
syntax_error_unterm_ch('"');
goto ret; /* error */
}
if (ch == '"') {
dest.o_expflags ^= EXP_FLAG_ESC_GLOB_CHARS;
continue;
}
if (ch == '\\') {
ch = i_getch(&input);
if (ch == EOF) {
//example? error message? syntax_error_unterm_ch('"');
debug_printf_parse("%s: error: \\<eof>\n", __func__);
goto ret;
}
o_addqchr(&dest, ch);
continue;
}
if (ch == '$') {
if (!parse_dollar(NULL, &dest, &input, /*quote_mask:*/ 0x80)) {
debug_printf_parse("%s: error: parse_dollar returned 0 (error)\n", __func__);
goto ret;
}
continue;
}
#if ENABLE_HUSH_TICK
if (ch == '`') {
//unsigned pos = dest->length;
o_addchr(&dest, SPECIAL_VAR_SYMBOL);
o_addchr(&dest, 0x80 | '`');
if (!add_till_backquote(&dest, &input,
/*in_dquote:*/ dest.o_expflags /* nonzero if EXP_FLAG_ESC_GLOB_CHARS set */
)
) {
goto ret; /* error */
}
o_addchr(&dest, SPECIAL_VAR_SYMBOL);
//debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
continue;
}
#endif
o_addQchr(&dest, ch);
} /* for (;;) */
debug_printf_parse("encode: '%s' -> '%s'\n", str, dest.data);
exp_str = expand_string_to_string(dest.data,
do_unbackslash ? EXP_FLAG_ESC_GLOB_CHARS : 0,
do_unbackslash
);
ret:
debug_printf_parse("expand: '%s' -> '%s'\n", dest.data, exp_str);
o_free(&dest);
return exp_str;
}
/* Expanding ARG in ${var+ARG}, ${var-ARG}
*/
static int encode_then_append_var_plusminus(o_string *output, int n,
char *str, int dquoted)
{
struct in_str input;
o_string dest = NULL_O_STRING;
if (!first_special_char_in_vararg(str)
&& '\0' == str[strcspn(str, G.ifs)]
) {
/* string has no special chars
* && string has no $IFS chars
*/
if (dquoted) {
/* Prints 1 (quoted expansion is a "" word, not nothing):
* set -- "${notexist-}"; echo $#
*/
output->has_quoted_part = 1;
}
return expand_vars_to_list(output, n, str);
}
setup_string_in_str(&input, str);
for (;;) {
int ch;
ch = i_getch(&input);
debug_printf_parse("%s: ch=%c (%d) escape=%x\n",
__func__, ch, ch, dest.o_expflags);
if (!dest.o_expflags) {
if (ch == EOF)
break;
if (!dquoted && strchr(G.ifs, ch)) {
/* PREFIX${x:d${e}f ...} and we met space: expand "d${e}f" and start new word.
* do not assume we are at the start of the word (PREFIX above).
*/
if (dest.data) {
n = expand_vars_to_list(output, n, dest.data);
o_free_and_set_NULL(&dest);
o_addchr(output, '\0');
n = o_save_ptr(output, n); /* create next word */
} else
if (output->length != o_get_last_ptr(output, n)
|| output->has_quoted_part
) {
/* For these cases:
* f() { for i; do echo "|$i|"; done; }; x=x
* f a${x:+ }b # 1st condition
* |a|
* |b|
* f ""${x:+ }b # 2nd condition
* ||
* |b|
*/
o_addchr(output, '\0');
n = o_save_ptr(output, n); /* create next word */
}
continue;
}
if (!dquoted && ch == '\'') {
if (!add_till_single_quote_dquoted(&dest, &input))
goto ret; /* error */
o_addchr(&dest, SPECIAL_VAR_SYMBOL);
o_addchr(&dest, SPECIAL_VAR_SYMBOL);
continue;
}
}
if (ch == EOF) {
syntax_error_unterm_ch('"');
goto ret; /* error */
}
if (ch == '"') {
dest.o_expflags ^= EXP_FLAG_ESC_GLOB_CHARS;
if (dest.o_expflags) {
o_addchr(&dest, SPECIAL_VAR_SYMBOL);
o_addchr(&dest, SPECIAL_VAR_SYMBOL);
}
continue;
}
if (ch == '\\') {
ch = i_getch(&input);
if (ch == EOF) {
//example? error message? syntax_error_unterm_ch('"');
debug_printf_parse("%s: error: \\<eof>\n", __func__);
goto ret;
}
o_addqchr(&dest, ch);
continue;
}
if (ch == '$') {
if (!parse_dollar(NULL, &dest, &input, /*quote_mask:*/ (dest.o_expflags || dquoted) ? 0x80 : 0)) {
debug_printf_parse("%s: error: parse_dollar returned 0 (error)\n", __func__);
goto ret;
}
continue;
}
#if ENABLE_HUSH_TICK
if (ch == '`') {
//unsigned pos = dest->length;
o_addchr(&dest, SPECIAL_VAR_SYMBOL);
o_addchr(&dest, (dest.o_expflags || dquoted) ? 0x80 | '`' : '`');
if (!add_till_backquote(&dest, &input,
/*in_dquote:*/ dest.o_expflags /* nonzero if EXP_FLAG_ESC_GLOB_CHARS set */
)
) {
goto ret; /* error */
}
o_addchr(&dest, SPECIAL_VAR_SYMBOL);
//debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
continue;
}
#endif
if (dquoted) {
/* Always glob-protect if in dquotes:
* x=x; echo "${x:+/bin/c*}" - prints: /bin/c*
* x=x; echo "${x:+"/bin/c*"}" - prints: /bin/c*
*/
o_addqchr(&dest, ch);
} else {
/* Glob-protect only if char is quoted:
* x=x; echo ${x:+/bin/c*} - prints many filenames
* x=x; echo ${x:+"/bin/c*"} - prints: /bin/c*
*/
o_addQchr(&dest, ch);
}
} /* for (;;) */
if (dest.data) {
n = expand_vars_to_list(output, n, dest.data);
}
ret:
o_free(&dest);
return n;
}
#if ENABLE_FEATURE_SH_MATH
static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
{
arith_state_t math_state;
arith_t res;
char *exp_str;
math_state.lookupvar = get_local_var_value;
math_state.setvar = set_local_var_from_halves;
//math_state.endofname = endofname;
exp_str = encode_then_expand_string(arg);
res = arith(&math_state, exp_str ? exp_str : arg);
free(exp_str);
if (errmsg_p)
*errmsg_p = math_state.errmsg;
if (math_state.errmsg)
msg_and_die_if_script(math_state.errmsg);
return res;
}
#endif
#if BASH_PATTERN_SUBST
/* ${var/[/]pattern[/repl]} helpers */
static char *strstr_pattern(char *val, const char *pattern, int *size)
{
while (1) {
char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
if (end) {
*size = end - val;
return val;
}
if (*val == '\0')
return NULL;
/* Optimization: if "*pat" did not match the start of "string",
* we know that "tring", "ring" etc will not match too:
*/
if (pattern[0] == '*')
return NULL;
val++;
}
}
static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
{
char *result = NULL;
unsigned res_len = 0;
unsigned repl_len = strlen(repl);
/* Null pattern never matches, including if "var" is empty */
if (!pattern[0])
return result; /* NULL, no replaces happened */
while (1) {
int size;
char *s = strstr_pattern(val, pattern, &size);
if (!s)
break;
result = xrealloc(result, res_len + (s - val) + repl_len + 1);
strcpy(mempcpy(result + res_len, val, s - val), repl);
res_len += (s - val) + repl_len;
debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
val = s + size;
if (exp_op == '/')
break;
}
if (*val && result) {
result = xrealloc(result, res_len + strlen(val) + 1);
strcpy(result + res_len, val);
debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
}
debug_printf_varexp("result:'%s'\n", result);
return result;
}
#endif /* BASH_PATTERN_SUBST */
static int append_str_maybe_ifs_split(o_string *output, int n,
int first_ch, const char *val)
{
if (!(first_ch & 0x80)) { /* unquoted $VAR */
debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
!!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
if (val && val[0])
n = expand_on_ifs(output, n, val);
} else { /* quoted "$VAR" */
output->has_quoted_part = 1;
debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
!!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
if (val && val[0])
o_addQstr(output, val);
}
return n;
}
/* Handle <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
*/
static NOINLINE int expand_one_var(o_string *output, int n,
int first_ch, char *arg, char **pp)
{
const char *val;
char *to_be_freed;
char *p;
char *var;
char exp_op;
char exp_save = exp_save; /* for compiler */
char *exp_saveptr; /* points to expansion operator */
char *exp_word = exp_word; /* for compiler */
char arg0;
val = NULL;
to_be_freed = NULL;
p = *pp;
*p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
var = arg;
exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
arg0 = arg[0];
arg[0] = (arg0 & 0x7f);
exp_op = 0;
if (arg[0] == '#' && arg[1] /* ${#...} but not ${#} */
&& (!exp_saveptr /* and ( not(${#<op_char>...}) */
|| (arg[2] == '\0' && strchr(SPECIAL_VARS_STR, arg[1])) /* or ${#C} "len of $C" ) */
) /* NB: skipping ^^^specvar check mishandles ${#::2} */
) {
/* It must be length operator: ${#var} */
var++;
exp_op = 'L';
} else {
/* Maybe handle parameter expansion */
if (exp_saveptr /* if 2nd char is one of expansion operators */
&& strchr(NUMERIC_SPECVARS_STR, arg[0]) /* 1st char is special variable */
) {
/* ${?:0}, ${#[:]%0} etc */
exp_saveptr = var + 1;
} else {
/* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
}
exp_op = exp_save = *exp_saveptr;
if (exp_op) {
exp_word = exp_saveptr + 1;
if (exp_op == ':') {
exp_op = *exp_word++;
//TODO: try ${var:} and ${var:bogus} in non-bash config
if (BASH_SUBSTR
&& (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
) {
/* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
exp_op = ':';
exp_word--;
}
}
*exp_saveptr = '\0';
} /* else: it's not an expansion op, but bare ${var} */
}
/* Look up the variable in question */
if (isdigit(var[0])) {
/* parse_dollar should have vetted var for us */
int nn = xatoi_positive(var);
if (nn < G.global_argc)
val = G.global_argv[nn];
/* else val remains NULL: $N with too big N */
} else {
switch (var[0]) {
case '$': /* pid */
val = utoa(G.root_pid);
break;
case '!': /* bg pid */
val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
break;
case '?': /* exitcode */
val = utoa(G.last_exitcode);
break;
case '#': /* argc */
val = utoa(G.global_argc ? G.global_argc-1 : 0);
break;
default:
val = get_local_var_value(var);
}
}
/* Handle any expansions */
if (exp_op == 'L') {
reinit_unicode_for_hush();
debug_printf_expand("expand: length(%s)=", val);
val = utoa(val ? unicode_strlen(val) : 0);
debug_printf_expand("%s\n", val);
} else if (exp_op) {
if (exp_op == '%' || exp_op == '#') {
/* Standard-mandated substring removal ops:
* ${parameter%word} - remove smallest suffix pattern
* ${parameter%%word} - remove largest suffix pattern
* ${parameter#word} - remove smallest prefix pattern
* ${parameter##word} - remove largest prefix pattern
*
* Word is expanded to produce a glob pattern.
* Then var's value is matched to it and matching part removed.
*/
//FIXME: ${x#...${...}...}
//should evaluate inner ${...} even if x is "" and no shrinking of it is possible -
//inner ${...} may have side effects!
if (val && val[0]) {
char *t;
char *exp_exp_word;
char *loc;
unsigned scan_flags = pick_scan(exp_op, *exp_word);
if (exp_op == *exp_word) /* ## or %% */
exp_word++;
debug_printf_expand("expand: exp_word:'%s'\n", exp_word);
exp_exp_word = encode_then_expand_vararg(exp_word, /*handle_squotes:*/ 1, /*unbackslash:*/ 0);
if (exp_exp_word)
exp_word = exp_exp_word;
debug_printf_expand("expand: exp_word:'%s'\n", exp_word);
/*
* HACK ALERT. We depend here on the fact that
* G.global_argv and results of utoa and get_local_var_value
* are actually in writable memory:
* scan_and_match momentarily stores NULs there.
*/
t = (char*)val;
loc = scan_and_match(t, exp_word, scan_flags);
debug_printf_expand("op:%c str:'%s' pat:'%s' res:'%s'\n", exp_op, t, exp_word, loc);
free(exp_exp_word);
if (loc) { /* match was found */
if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
val = loc; /* take right part */
else /* %[%] */
val = to_be_freed = xstrndup(val, loc - val); /* left */
}
}
}
#if BASH_PATTERN_SUBST
else if (exp_op == '/' || exp_op == '\\') {
/* It's ${var/[/]pattern[/repl]} thing.
* Note that in encoded form it has TWO parts:
* var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
* and if // is used, it is encoded as \:
* var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
*/
if (val && val[0]) {
/* pattern uses non-standard expansion.
* repl should be unbackslashed and globbed
* by the usual expansion rules:
* >az >bz
* v='a bz'; echo "${v/a*z/a*z}" #prints "a*z"
* v='a bz'; echo "${v/a*z/\z}" #prints "z"
* v='a bz'; echo ${v/a*z/a*z} #prints "az"
* v='a bz'; echo ${v/a*z/\z} #prints "z"
* (note that a*z _pattern_ is never globbed!)
*/
char *pattern, *repl, *t;
pattern = encode_then_expand_vararg(exp_word, /*handle_squotes:*/ 1, /*unbackslash:*/ 0);
if (!pattern)
pattern = xstrdup(exp_word);
debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
*p++ = SPECIAL_VAR_SYMBOL;
exp_word = p;
p = strchr(p, SPECIAL_VAR_SYMBOL);
*p = '\0';
repl = encode_then_expand_vararg(exp_word, /*handle_squotes:*/ 1, /*unbackslash:*/ 1);
debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
/* HACK ALERT. We depend here on the fact that
* G.global_argv and results of utoa and get_local_var_value
* are actually in writable memory:
* replace_pattern momentarily stores NULs there. */
t = (char*)val;
to_be_freed = replace_pattern(t,
pattern,
(repl ? repl : exp_word),
exp_op);
if (to_be_freed) /* at least one replace happened */
val = to_be_freed;
free(pattern);
free(repl);
} else {
/* Empty variable always gives nothing */
// "v=''; echo ${v/*/w}" prints "", not "w"
/* Just skip "replace" part */
*p++ = SPECIAL_VAR_SYMBOL;
p = strchr(p, SPECIAL_VAR_SYMBOL);
*p = '\0';
}
}
#endif /* BASH_PATTERN_SUBST */
else if (exp_op == ':') {
#if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
/* It's ${var:N[:M]} bashism.
* Note that in encoded form it has TWO parts:
* var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
*/
arith_t beg, len;
const char *errmsg;
beg = expand_and_evaluate_arith(exp_word, &errmsg);
if (errmsg)
goto arith_err;
debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
*p++ = SPECIAL_VAR_SYMBOL;
exp_word = p;
p = strchr(p, SPECIAL_VAR_SYMBOL);
*p = '\0';
len = expand_and_evaluate_arith(exp_word, &errmsg);
if (errmsg)
goto arith_err;
debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
if (beg < 0) {
/* negative beg counts from the end */
beg = (arith_t)strlen(val) + beg;
if (beg < 0) /* ${v: -999999} is "" */
beg = len = 0;
}
debug_printf_varexp("from val:'%s'\n", val);
if (len < 0) {
/* in bash, len=-n means strlen()-n */
len = (arith_t)strlen(val) - beg + len;
if (len < 0) /* bash compat */
msg_and_die_if_script("%s: substring expression < 0", var);
}
if (len <= 0 || !val || beg >= strlen(val)) {
arith_err:
val = NULL;
} else {
/* Paranoia. What if user entered 9999999999999
* which fits in arith_t but not int? */
if (len >= INT_MAX)
len = INT_MAX;
val = to_be_freed = xstrndup(val + beg, len);
}
debug_printf_varexp("val:'%s'\n", val);
#else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
msg_and_die_if_script("malformed ${%s:...}", var);
val = NULL;
#endif
} else { /* one of "-=+?" */
/* Standard-mandated substitution ops:
* ${var?word} - indicate error if unset
* If var is unset, word (or a message indicating it is unset
* if word is null) is written to standard error
* and the shell exits with a non-zero exit status.
* Otherwise, the value of var is substituted.
* ${var-word} - use default value
* If var is unset, word is substituted.
* ${var=word} - assign and use default value
* If var is unset, word is assigned to var.
* In all cases, final value of var is substituted.
* ${var+word} - use alternative value
* If var is unset, null is substituted.
* Otherwise, word is substituted.
*
* Word is subjected to tilde expansion, parameter expansion,
* command substitution, and arithmetic expansion.
* If word is not needed, it is not expanded.
*
* Colon forms (${var:-word}, ${var:=word} etc) do the same,
* but also treat null var as if it is unset.
*
* Word-splitting and single quote behavior:
*
* $ f() { for i; do echo "|$i|"; done; };
*
* $ x=; f ${x:?'x y' z}
* bash: x: x y z #BUG: does not abort, ${} results in empty expansion
* $ x=; f "${x:?'x y' z}"
* bash: x: x y z # dash prints: dash: x: 'x y' z #BUG: does not abort, ${} results in ""
*
* $ x=; f ${x:='x y' z}
* |x|
* |y|
* |z|
* $ x=; f "${x:='x y' z}"
* |'x y' z|
*
* $ x=x; f ${x:+'x y' z}
* |x y|
* |z|
* $ x=x; f "${x:+'x y' z}"
* |'x y' z|
*
* $ x=; f ${x:-'x y' z}
* |x y|
* |z|
* $ x=; f "${x:-'x y' z}"
* |'x y' z|
*/
int use_word = (!val || ((exp_save == ':') && !val[0]));
if (exp_op == '+')
use_word = !use_word;
debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
(exp_save == ':') ? "true" : "false", use_word);
if (use_word) {
if (exp_op == '+' || exp_op == '-') {
/* ${var+word} - use alternative value */
/* ${var-word} - use default value */
n = encode_then_append_var_plusminus(output, n, exp_word,
/*dquoted:*/ (arg0 & 0x80)
);
val = NULL;
} else {
/* ${var?word} - indicate error if unset */
/* ${var=word} - assign and use default value */
to_be_freed = encode_then_expand_vararg(exp_word,
/*handle_squotes:*/ !(arg0 & 0x80),
/*unbackslash:*/ 0
);
if (to_be_freed)
exp_word = to_be_freed;
if (exp_op == '?') {
/* mimic bash message */
msg_and_die_if_script("%s: %s",
var,
exp_word[0]
? exp_word
: "parameter null or not set"
/* ash has more specific messages, a-la: */
/*: (exp_save == ':' ? "parameter null or not set" : "parameter not set")*/
);
//TODO: how interactive bash aborts expansion mid-command?
//It aborts the entire line, returns to prompt:
// $ f() { for i; do echo "|$i|"; done; }; x=; f "${x:?'x y' z}"; echo YO
// bash: x: x y z
// $
// ("echo YO" is not executed, neither the f function call)
} else {
val = exp_word;
}
if (exp_op == '=') {
/* ${var=[word]} or ${var:=[word]} */
if (isdigit(var[0]) || var[0] == '#') {
/* mimic bash message */
msg_and_die_if_script("$%s: cannot assign in this way", var);
val = NULL;
} else {
char *new_var = xasprintf("%s=%s", var, val);
set_local_var(new_var, /*flag:*/ 0);
}
}
}
}
} /* one of "-=+?" */
*exp_saveptr = exp_save;
} /* if (exp_op) */
arg[0] = arg0;
*pp = p;
n = append_str_maybe_ifs_split(output, n, first_ch, val);
free(to_be_freed);
return n;
}
/* Expand all variable references in given string, adding words to list[]
* at n, n+1,... positions. Return updated n (so that list[n] is next one
* to be filled). This routine is extremely tricky: has to deal with
* variables/parameters with whitespace, $* and $@, and constructs like
* 'echo -$*-'. If you play here, you must run testsuite afterwards! */
static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
{
/* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
* expansion of right-hand side of assignment == 1-element expand.
*/
char cant_be_null = 0; /* only bit 0x80 matters */
char *p;
debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
!!(output->o_expflags & EXP_FLAG_SINGLEWORD));
debug_print_list("expand_vars_to_list[0]", output, n);
while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
char first_ch;
#if ENABLE_FEATURE_SH_MATH
char arith_buf[sizeof(arith_t)*3 + 2];
#endif
if (output->ended_in_ifs) {
o_addchr(output, '\0');
n = o_save_ptr(output, n);
output->ended_in_ifs = 0;
}
o_addblock(output, arg, p - arg);
debug_print_list("expand_vars_to_list[1]", output, n);
arg = ++p;
p = strchr(p, SPECIAL_VAR_SYMBOL);
/* Fetch special var name (if it is indeed one of them)
* and quote bit, force the bit on if singleword expansion -
* important for not getting v=$@ expand to many words. */
first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
/* Is this variable quoted and thus expansion can't be null?
* "$@" is special. Even if quoted, it can still
* expand to nothing (not even an empty string),
* thus it is excluded. */
if ((first_ch & 0x7f) != '@')
cant_be_null |= first_ch;
switch (first_ch & 0x7f) {
/* Highest bit in first_ch indicates that var is double-quoted */
case '*':
case '@': {
int i;
if (!G.global_argv[1])
break;
i = 1;
cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
while (G.global_argv[i]) {
n = expand_on_ifs(output, n, G.global_argv[i]);
debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
if (G.global_argv[i++][0] && G.global_argv[i]) {
/* this argv[] is not empty and not last:
* put terminating NUL, start new word */
o_addchr(output, '\0');
debug_print_list("expand_vars_to_list[2]", output, n);
n = o_save_ptr(output, n);
debug_print_list("expand_vars_to_list[3]", output, n);
}
}
} else
/* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
* and in this case should treat it like '$*' - see 'else...' below */
if (first_ch == (char)('@'|0x80) /* quoted $@ */
&& !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
) {
while (1) {
o_addQstr(output, G.global_argv[i]);
if (++i >= G.global_argc)
break;
o_addchr(output, '\0');
debug_print_list("expand_vars_to_list[4]", output, n);
n = o_save_ptr(output, n);
}
} else { /* quoted $* (or v="$@" case): add as one word */
while (1) {
o_addQstr(output, G.global_argv[i]);
if (!G.global_argv[++i])
break;
if (G.ifs[0])
o_addchr(output, G.ifs[0]);
}
output->has_quoted_part = 1;
}
break;
}
case SPECIAL_VAR_SYMBOL: {
/* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
/* "Empty variable", used to make "" etc to not disappear */
output->has_quoted_part = 1;
cant_be_null = 0x80;
arg++;
break;
}
case SPECIAL_VAR_QUOTED_SVS:
/* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_QUOTED_SVS><SPECIAL_VAR_SYMBOL> */
/* "^C variable", represents literal ^C char (possible in scripts) */
o_addchr(output, SPECIAL_VAR_SYMBOL);
arg++;
break;
#if ENABLE_HUSH_TICK
case '`': {
/* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
o_string subst_result = NULL_O_STRING;
*p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
arg++;
/* Can't just stuff it into output o_string,
* expanded result may need to be globbed
* and $IFS-split */
debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
G.last_exitcode = process_command_subs(&subst_result, arg);
G.expand_exitcode = G.last_exitcode;
debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
n = append_str_maybe_ifs_split(output, n, first_ch, subst_result.data);
o_free(&subst_result);
break;
}
#endif
#if ENABLE_FEATURE_SH_MATH
case '+': {
/* <SPECIAL_VAR_SYMBOL>+arith<SPECIAL_VAR_SYMBOL> */
arith_t res;
arg++; /* skip '+' */
*p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
res = expand_and_evaluate_arith(arg, NULL);
debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
sprintf(arith_buf, ARITH_FMT, res);
o_addstr(output, arith_buf);
break;
}
#endif
default:
/* <SPECIAL_VAR_SYMBOL>varname[ops]<SPECIAL_VAR_SYMBOL> */
n = expand_one_var(output, n, first_ch, arg, &p);
break;
} /* switch (char after <SPECIAL_VAR_SYMBOL>) */
/* Restore NULL'ed SPECIAL_VAR_SYMBOL.
* Do the check to avoid writing to a const string. */
if (*p != SPECIAL_VAR_SYMBOL)
*p = SPECIAL_VAR_SYMBOL;
arg = ++p;
} /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
if (*arg) {
/* handle trailing string */
if (output->ended_in_ifs) {
o_addchr(output, '\0');
n = o_save_ptr(output, n);
}
debug_print_list("expand_vars_to_list[a]", output, n);
/* this part is literal, and it was already pre-quoted
* if needed (much earlier), do not use o_addQstr here!
*/
o_addstr(output, arg);
debug_print_list("expand_vars_to_list[b]", output, n);
} else
if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
&& !(cant_be_null & 0x80) /* and all vars were not quoted */
&& !output->has_quoted_part
) {
n--;
/* allow to reuse list[n] later without re-growth */
output->has_empty_slot = 1;
}
return n;
}
static char **expand_variables(char **argv, unsigned expflags)
{
int n;
char **list;
o_string output = NULL_O_STRING;
output.o_expflags = expflags;
n = 0;
for (;;) {
/* go to next list[n] */
output.ended_in_ifs = 0;
n = o_save_ptr(&output, n);
if (!*argv)
break;
/* expand argv[i] */
n = expand_vars_to_list(&output, n, *argv++);
/* if (!output->has_empty_slot) -- need this?? */
o_addchr(&output, '\0');
}
debug_print_list("expand_variables", &output, n);
/* output.data (malloced in one block) gets returned in "list" */
list = o_finalize_list(&output, n);
debug_print_strings("expand_variables[1]", list);
return list;
}
static char **expand_strvec_to_strvec(char **argv)
{
return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
}
#if defined(CMD_SINGLEWORD_NOGLOB)
static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
{
return expand_variables(argv, EXP_FLAG_SINGLEWORD);
}
#endif
/* Used for expansion of right hand of assignments,
* $((...)), heredocs, variable expansion parts.
*
* NB: should NOT do globbing!
* "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
*/
static char *expand_string_to_string(const char *str, int EXP_flags, int do_unbackslash)
{
#if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
const int do_unbackslash = 1;
const int EXP_flags = EXP_FLAG_ESC_GLOB_CHARS;
#endif
char *argv[2], **list;
debug_printf_expand("string_to_string<='%s'\n", str);
/* This is generally an optimization, but it also
* handles "", which otherwise trips over !list[0] check below.
* (is this ever happens that we actually get str="" here?)
*/
if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
//TODO: Can use on strings with \ too, just unbackslash() them?
debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
return xstrdup(str);
}
argv[0] = (char*)str;
argv[1] = NULL;
list = expand_variables(argv, EXP_flags | EXP_FLAG_SINGLEWORD);
if (!list[0]) {
/* Example where it happens:
* x=; echo ${x:-"$@"}
*/
((char*)list)[0] = '\0';
} else {
if (HUSH_DEBUG)
if (list[1])
bb_error_msg_and_die("BUG in varexp2");
/* actually, just move string 2*sizeof(char*) bytes back */
overlapping_strcpy((char*)list, list[0]);
if (do_unbackslash)
unbackslash((char*)list);
}
debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
return (char*)list;
}
#if 0
static char* expand_strvec_to_string(char **argv)
{
char **list;
list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
/* Convert all NULs to spaces */
if (list[0]) {
int n = 1;
while (list[n]) {
if (HUSH_DEBUG)
if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
bb_error_msg_and_die("BUG in varexp3");
/* bash uses ' ' regardless of $IFS contents */
list[n][-1] = ' ';
n++;
}
}
overlapping_strcpy((char*)list, list[0] ? list[0] : "");
debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
return (char*)list;
}
#endif
static char **expand_assignments(char **argv, int count)
{
int i;
char **p;
G.expanded_assignments = p = NULL;
/* Expand assignments into one string each */
for (i = 0; i < count; i++) {
p = add_string_to_strings(p,
expand_string_to_string(argv[i],
EXP_FLAG_ESC_GLOB_CHARS,
/*unbackslash:*/ 1
)
);
G.expanded_assignments = p;
}
G.expanded_assignments = NULL;
return p;
}
static void switch_off_special_sigs(unsigned mask)
{
unsigned sig = 0;
while ((mask >>= 1) != 0) {
sig++;
if (!(mask & 1))
continue;
#if ENABLE_HUSH_TRAP
if (G_traps) {
if (G_traps[sig] && !G_traps[sig][0])
/* trap is '', has to remain SIG_IGN */
continue;
free(G_traps[sig]);
G_traps[sig] = NULL;
}
#endif
/* We are here only if no trap or trap was not '' */
install_sighandler(sig, SIG_DFL);
}
}
#if BB_MMU
/* never called */
void re_execute_shell(char ***to_free, const char *s,
char *g_argv0, char **g_argv,
char **builtin_argv) NORETURN;
static void reset_traps_to_defaults(void)
{
/* This function is always called in a child shell
* after fork (not vfork, NOMMU doesn't use this function).
*/
IF_HUSH_TRAP(unsigned sig;)
unsigned mask;
/* Child shells are not interactive.
* SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
* Testcase: (while :; do :; done) + ^Z should background.
* Same goes for SIGTERM, SIGHUP, SIGINT.
*/
mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
if (!G_traps && !mask)
return; /* already no traps and no special sigs */
/* Switch off special sigs */
switch_off_special_sigs(mask);
# if ENABLE_HUSH_JOB
G_fatal_sig_mask = 0;
# endif
G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
/* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
* remain set in G.special_sig_mask */
# if ENABLE_HUSH_TRAP
if (!G_traps)
return;
/* Reset all sigs to default except ones with empty traps */
for (sig = 0; sig < NSIG; sig++) {
if (!G_traps[sig])
continue; /* no trap: nothing to do */
if (!G_traps[sig][0])
continue; /* empty trap: has to remain SIG_IGN */
/* sig has non-empty trap, reset it: */
free(G_traps[sig]);
G_traps[sig] = NULL;
/* There is no signal for trap 0 (EXIT) */
if (sig == 0)
continue;
install_sighandler(sig, pick_sighandler(sig));
}
# endif
}
#else /* !BB_MMU */
static void re_execute_shell(char ***to_free, const char *s,
char *g_argv0, char **g_argv,
char **builtin_argv) NORETURN;
static void re_execute_shell(char ***to_free, const char *s,
char *g_argv0, char **g_argv,
char **builtin_argv)
{
# define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
/* delims + 2 * (number of bytes in printed hex numbers) */
char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
char *heredoc_argv[4];
struct variable *cur;
# if ENABLE_HUSH_FUNCTIONS
struct function *funcp;
# endif
char **argv, **pp;
unsigned cnt;
unsigned long long empty_trap_mask;
if (!g_argv0) { /* heredoc */
argv = heredoc_argv;
argv[0] = (char *) G.argv0_for_re_execing;
argv[1] = (char *) "-<";
argv[2] = (char *) s;
argv[3] = NULL;
pp = &argv[3]; /* used as pointer to empty environment */
goto do_exec;
}
cnt = 0;
pp = builtin_argv;
if (pp) while (*pp++)
cnt++;
empty_trap_mask = 0;
if (G_traps) {
int sig;
for (sig = 1; sig < NSIG; sig++) {
if (G_traps[sig] && !G_traps[sig][0])
empty_trap_mask |= 1LL << sig;
}
}
sprintf(param_buf, NOMMU_HACK_FMT
, (unsigned) G.root_pid
, (unsigned) G.root_ppid
, (unsigned) G.last_bg_pid
, (unsigned) G.last_exitcode
, cnt
, empty_trap_mask
IF_HUSH_LOOPS(, G.depth_of_loop)
);
# undef NOMMU_HACK_FMT
/* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
* 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
*/
cnt += 6;
for (cur = G.top_var; cur; cur = cur->next) {
if (!cur->flg_export || cur->flg_read_only)
cnt += 2;
}
# if ENABLE_HUSH_FUNCTIONS
for (funcp = G.top_func; funcp; funcp = funcp->next)
cnt += 3;
# endif
pp = g_argv;
while (*pp++)
cnt++;
*to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
*pp++ = (char *) G.argv0_for_re_execing;
*pp++ = param_buf;
for (cur = G.top_var; cur; cur = cur->next) {
if (strcmp(cur->varstr, hush_version_str) == 0)
continue;
if (cur->flg_read_only) {
*pp++ = (char *) "-R";
*pp++ = cur->varstr;
} else if (!cur->flg_export) {
*pp++ = (char *) "-V";
*pp++ = cur->varstr;
}
}
# if ENABLE_HUSH_FUNCTIONS
for (funcp = G.top_func; funcp; funcp = funcp->next) {
*pp++ = (char *) "-F";
*pp++ = funcp->name;
*pp++ = funcp->body_as_string;
}
# endif
/* We can pass activated traps here. Say, -Tnn:trap_string
*
* However, POSIX says that subshells reset signals with traps
* to SIG_DFL.
* I tested bash-3.2 and it not only does that with true subshells
* of the form ( list ), but with any forked children shells.
* I set trap "echo W" WINCH; and then tried:
*
* { echo 1; sleep 20; echo 2; } &
* while true; do echo 1; sleep 20; echo 2; break; done &
* true | { echo 1; sleep 20; echo 2; } | cat
*
* In all these cases sending SIGWINCH to the child shell
* did not run the trap. If I add trap "echo V" WINCH;
* _inside_ group (just before echo 1), it works.
*
* I conclude it means we don't need to pass active traps here.
*/
*pp++ = (char *) "-c";
*pp++ = (char *) s;
if (builtin_argv) {
while (*++builtin_argv)
*pp++ = *builtin_argv;
*pp++ = (char *) "";
}
*pp++ = g_argv0;
while (*g_argv)
*pp++ = *g_argv++;
/* *pp = NULL; - is already there */
pp = environ;
do_exec:
debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
/* Don't propagate SIG_IGN to the child */
if (SPECIAL_JOBSTOP_SIGS != 0)
switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
execve(bb_busybox_exec_path, argv, pp);
/* Fallback. Useful for init=/bin/hush usage etc */
if (argv[0][0] == '/')
execve(argv[0], argv, pp);
xfunc_error_retval = 127;
bb_error_msg_and_die("can't re-execute the shell");
}
#endif /* !BB_MMU */
static int run_and_free_list(struct pipe *pi);
/* Executing from string: eval, sh -c '...'
* or from file: /etc/profile, . file, sh <script>, sh (intereactive)
* end_trigger controls how often we stop parsing
* NUL: parse all, execute, return
* ';': parse till ';' or newline, execute, repeat till EOF
*/
static void parse_and_run_stream(struct in_str *inp, int end_trigger)
{
/* Why we need empty flag?
* An obscure corner case "false; ``; echo $?":
* empty command in `` should still set $? to 0.
* But we can't just set $? to 0 at the start,
* this breaks "false; echo `echo $?`" case.
*/
bool empty = 1;
while (1) {
struct pipe *pipe_list;
#if ENABLE_HUSH_INTERACTIVE
if (end_trigger == ';') {
G.promptmode = 0; /* PS1 */
debug_printf_prompt("%s promptmode=%d\n", __func__, G.promptmode);
}
#endif
pipe_list = parse_stream(NULL, NULL, inp, end_trigger);
if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
/* If we are in "big" script
* (not in `cmd` or something similar)...
*/
if (pipe_list == ERR_PTR && end_trigger == ';') {
/* Discard cached input (rest of line) */
int ch = inp->last_char;
while (ch != EOF && ch != '\n') {
//bb_error_msg("Discarded:'%c'", ch);
ch = i_getch(inp);
}
/* Force prompt */
inp->p = NULL;
/* This stream isn't empty */
empty = 0;
continue;
}
if (!pipe_list && empty)
G.last_exitcode = 0;
break;
}
debug_print_tree(pipe_list, 0);
debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
run_and_free_list(pipe_list);
empty = 0;
if (G_flag_return_in_progress == 1)
break;
}
}
static void parse_and_run_string(const char *s)
{
struct in_str input;
//IF_HUSH_LINENO_VAR(unsigned sv = G.lineno;)
setup_string_in_str(&input, s);
parse_and_run_stream(&input, '\0');
//IF_HUSH_LINENO_VAR(G.lineno = sv;)
}
static void parse_and_run_file(HFILE *fp)
{
struct in_str input;
IF_HUSH_LINENO_VAR(unsigned sv = G.lineno;)
IF_HUSH_LINENO_VAR(G.lineno = 1;)
setup_file_in_str(&input, fp);
parse_and_run_stream(&input, ';');
IF_HUSH_LINENO_VAR(G.lineno = sv;)
}
#if ENABLE_HUSH_TICK
static int generate_stream_from_string(const char *s, pid_t *pid_p)
{
pid_t pid;
int channel[2];
# if !BB_MMU
char **to_free = NULL;
# endif
xpipe(channel);
pid = BB_MMU ? xfork() : xvfork();
if (pid == 0) { /* child */
disable_restore_tty_pgrp_on_exit();
/* Process substitution is not considered to be usual
* 'command execution'.
* SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
*/
bb_signals(0
+ (1 << SIGTSTP)
+ (1 << SIGTTIN)
+ (1 << SIGTTOU)
, SIG_IGN);
close(channel[0]); /* NB: close _first_, then move fd! */
xmove_fd(channel[1], 1);
# if ENABLE_HUSH_TRAP
/* Awful hack for `trap` or $(trap).
*
* http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
* contains an example where "trap" is executed in a subshell:
*
* save_traps=$(trap)
* ...
* eval "$save_traps"
*
* Standard does not say that "trap" in subshell shall print
* parent shell's traps. It only says that its output
* must have suitable form, but then, in the above example
* (which is not supposed to be normative), it implies that.
*
* bash (and probably other shell) does implement it
* (traps are reset to defaults, but "trap" still shows them),
* but as a result, "trap" logic is hopelessly messed up:
*
* # trap
* trap -- 'echo Ho' SIGWINCH <--- we have a handler
* # (trap) <--- trap is in subshell - no output (correct, traps are reset)
* # true | trap <--- trap is in subshell - no output (ditto)
* # echo `true | trap` <--- in subshell - output (but traps are reset!)
* trap -- 'echo Ho' SIGWINCH
* # echo `(trap)` <--- in subshell in subshell - output
* trap -- 'echo Ho' SIGWINCH
* # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
* trap -- 'echo Ho' SIGWINCH
*
* The rules when to forget and when to not forget traps
* get really complex and nonsensical.
*
* Our solution: ONLY bare $(trap) or `trap` is special.
*/
s = skip_whitespace(s);
if (is_prefixed_with(s, "trap")
&& skip_whitespace(s + 4)[0] == '\0'
) {
static const char *const argv[] = { NULL, NULL };
builtin_trap((char**)argv);
fflush_all(); /* important */
_exit(0);
}
# endif
# if BB_MMU
/* Prevent it from trying to handle ctrl-z etc */
IF_HUSH_JOB(G.run_list_level = 1;)
CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
reset_traps_to_defaults();
IF_HUSH_MODE_X(G.x_mode_depth++;)
//bb_error_msg("%s: ++x_mode_depth=%d", __func__, G.x_mode_depth);
parse_and_run_string(s);
_exit(G.last_exitcode);
# else
/* We re-execute after vfork on NOMMU. This makes this script safe:
* yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
* huge=`cat BIG` # was blocking here forever
* echo OK
*/
re_execute_shell(&to_free,
s,
G.global_argv[0],
G.global_argv + 1,
NULL);
# endif
}
/* parent */
*pid_p = pid;
# if ENABLE_HUSH_FAST
G.count_SIGCHLD++;
//bb_error_msg("[%d] fork in generate_stream_from_string:"
// " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
// getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
# endif
enable_restore_tty_pgrp_on_exit();
# if !BB_MMU
free(to_free);
# endif
close(channel[1]);
return channel[0];
}
/* Return code is exit status of the process that is run. */
static int process_command_subs(o_string *dest, const char *s)
{
FILE *fp;
pid_t pid;
int status, ch, eol_cnt;
fp = xfdopen_for_read(generate_stream_from_string(s, &pid));
/* Now send results of command back into original context */
eol_cnt = 0;
while ((ch = getc(fp)) != EOF) {
if (ch == '\0')
continue;
if (ch == '\n') {
eol_cnt++;
continue;
}
while (eol_cnt) {
o_addchr(dest, '\n');
eol_cnt--;
}
o_addQchr(dest, ch);
}
debug_printf("done reading from `cmd` pipe, closing it\n");
fclose(fp);
/* We need to extract exitcode. Test case
* "true; echo `sleep 1; false` $?"
* should print 1 */
safe_waitpid(pid, &status, 0);
debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
return WEXITSTATUS(status);
}
#endif /* ENABLE_HUSH_TICK */
static void setup_heredoc(struct redir_struct *redir)
{
struct fd_pair pair;
pid_t pid;
int len, written;
/* the _body_ of heredoc (misleading field name) */
const char *heredoc = redir->rd_filename;
char *expanded;
#if !BB_MMU
char **to_free;
#endif
expanded = NULL;
if (!(redir->rd_dup & HEREDOC_QUOTED)) {
expanded = encode_then_expand_string(heredoc);
if (expanded)
heredoc = expanded;
}
len = strlen(heredoc);
close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
xpiped_pair(pair);
xmove_fd(pair.rd, redir->rd_fd);
/* Try writing without forking. Newer kernels have
* dynamically growing pipes. Must use non-blocking write! */
ndelay_on(pair.wr);
while (1) {
written = write(pair.wr, heredoc, len);
if (written <= 0)
break;
len -= written;
if (len == 0) {
close(pair.wr);
free(expanded);
return;
}
heredoc += written;
}
ndelay_off(pair.wr);
/* Okay, pipe buffer was not big enough */
/* Note: we must not create a stray child (bastard? :)
* for the unsuspecting parent process. Child creates a grandchild
* and exits before parent execs the process which consumes heredoc
* (that exec happens after we return from this function) */
#if !BB_MMU
to_free = NULL;
#endif
pid = xvfork();
if (pid == 0) {
/* child */
disable_restore_tty_pgrp_on_exit();
pid = BB_MMU ? xfork() : xvfork();
if (pid != 0)
_exit(0);
/* grandchild */
close(redir->rd_fd); /* read side of the pipe */
#if BB_MMU
full_write(pair.wr, heredoc, len); /* may loop or block */
_exit(0);
#else
/* Delegate blocking writes to another process */
xmove_fd(pair.wr, STDOUT_FILENO);
re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
#endif
}
/* parent */
#if ENABLE_HUSH_FAST
G.count_SIGCHLD++;
//bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
#endif
enable_restore_tty_pgrp_on_exit();
#if !BB_MMU
free(to_free);
#endif
close(pair.wr);
free(expanded);
wait(NULL); /* wait till child has died */
}
struct squirrel {
int orig_fd;
int moved_to;
/* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
/* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
};
static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved)
{
sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
sq[i].orig_fd = orig;
sq[i].moved_to = moved;
sq[i+1].orig_fd = -1; /* end marker */
return sq;
}
static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
{
int moved_to;
int i;
i = 0;
if (sq) for (; sq[i].orig_fd >= 0; i++) {
/* If we collide with an already moved fd... */
if (fd == sq[i].moved_to) {
sq[i].moved_to = dup_CLOEXEC(sq[i].moved_to, avoid_fd);
debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
if (sq[i].moved_to < 0) /* what? */
xfunc_die();
return sq;
}
if (fd == sq[i].orig_fd) {
/* Example: echo Hello >/dev/null 1>&2 */
debug_printf_redir("redirect_fd %d: already moved\n", fd);
return sq;
}
}
/* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
moved_to = dup_CLOEXEC(fd, avoid_fd);
debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
if (moved_to < 0 && errno != EBADF)
xfunc_die();
return append_squirrel(sq, i, fd, moved_to);
}
static struct squirrel *add_squirrel_closed(struct squirrel *sq, int fd)
{
int i;
i = 0;
if (sq) for (; sq[i].orig_fd >= 0; i++) {
/* If we collide with an already moved fd... */
if (fd == sq[i].orig_fd) {
/* Examples:
* "echo 3>FILE 3>&- 3>FILE"
* "echo 3>&- 3>FILE"
* No need for last redirect to insert
* another "need to close 3" indicator.
*/
debug_printf_redir("redirect_fd %d: already moved or closed\n", fd);
return sq;
}
}
debug_printf_redir("redirect_fd %d: previous fd was closed\n", fd);
return append_squirrel(sq, i, fd, -1);
}
/* fd: redirect wants this fd to be used (e.g. 3>file).
* Move all conflicting internally used fds,
* and remember them so that we can restore them later.
*/
static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
{
if (avoid_fd < 9) /* the important case here is that it can be -1 */
avoid_fd = 9;
#if ENABLE_HUSH_INTERACTIVE
if (fd == G_interactive_fd) {
/* Testcase: "ls -l /proc/$$/fd 255>&-" should work */
G_interactive_fd = xdup_CLOEXEC_and_close(G_interactive_fd, avoid_fd);
debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G_interactive_fd);
return 1; /* "we closed fd" */
}
#endif
/* Are we called from setup_redirects(squirrel==NULL)
* in redirect in a [v]forked child?
*/
if (sqp == NULL) {
/* No need to move script fds.
* For NOMMU case, it's actively wrong: we'd change ->fd
* fields in memory for the parent, but parent's fds
* aren't be moved, it would use wrong fd!
* Reproducer: "cmd 3>FILE" in script.
* If we would call move_HFILEs_on_redirect(), child would:
* fcntl64(3, F_DUPFD_CLOEXEC, 10) = 10
* close(3) = 0
* and change ->fd to 10 if fd#3 is a script fd. WRONG.
*/
//bb_error_msg("sqp == NULL: [v]forked child");
return 0;
}
/* If this one of script's fds? */
if (move_HFILEs_on_redirect(fd, avoid_fd))
return 1; /* yes. "we closed fd" (actually moved it) */
/* Are we called for "exec 3>FILE"? Came through
* redirect_and_varexp_helper(squirrel=ERR_PTR) -> setup_redirects(ERR_PTR)
* This case used to fail for this script:
* exec 3>FILE
* echo Ok
* ...100000 more lines...
* echo Ok
* as follows:
* read(3, "exec 3>FILE\necho Ok\necho Ok"..., 1024) = 1024
* open("FILE", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE, 0666) = 4
* dup2(4, 3) = 3
* ^^^^^^^^ oops, we lost fd#3 opened to our script!
* close(4) = 0
* write(1, "Ok\n", 3) = 3
* ... = 3
* write(1, "Ok\n", 3) = 3
* read(3, 0x94fbc08, 1024) = -1 EBADF (Bad file descriptor)
* ^^^^^^^^ oops, wrong fd!!!
* With this case separate from sqp == NULL and *after* move_HFILEs,
* it now works:
*/
if (sqp == ERR_PTR) {
/* Don't preserve redirected fds: exec is _meant_ to change these */
//bb_error_msg("sqp == ERR_PTR: exec >FILE");
return 0;
}
/* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
*sqp = add_squirrel(*sqp, fd, avoid_fd);
return 0; /* "we did not close fd" */
}
static void restore_redirects(struct squirrel *sq)
{
if (sq) {
int i;
for (i = 0; sq[i].orig_fd >= 0; i++) {
if (sq[i].moved_to >= 0) {
/* We simply die on error */
debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
xmove_fd(sq[i].moved_to, sq[i].orig_fd);
} else {
/* cmd1 9>FILE; cmd2_should_see_fd9_closed */
debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
close(sq[i].orig_fd);
}
}
free(sq);
}
/* If moved, G_interactive_fd stays on new fd, not restoring it */
}
#if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
static void close_saved_fds_and_FILE_fds(void)
{
if (G_interactive_fd)
close(G_interactive_fd);
close_all_HFILE_list();
}
#endif
static int internally_opened_fd(int fd, struct squirrel *sq)
{
int i;
#if ENABLE_HUSH_INTERACTIVE
if (fd == G_interactive_fd)
return 1;
#endif
/* If this one of script's fds? */
if (fd_in_HFILEs(fd))
return 1;
if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
if (fd == sq[i].moved_to)
return 1;
}
return 0;
}
/* squirrel != NULL means we squirrel away copies of stdin, stdout,
* and stderr if they are redirected. */
static int setup_redirects(struct command *prog, struct squirrel **sqp)
{
struct redir_struct *redir;
for (redir = prog->redirects; redir; redir = redir->next) {
int newfd;
int closed;
if (redir->rd_type == REDIRECT_HEREDOC2) {
/* "rd_fd<<HERE" case */
save_fd_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
/* for REDIRECT_HEREDOC2, rd_filename holds _contents_
* of the heredoc */
debug_printf_redir("set heredoc '%s'\n",
redir->rd_filename);
setup_heredoc(redir);
continue;
}
if (redir->rd_dup == REDIRFD_TO_FILE) {
/* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
char *p;
int mode;
if (redir->rd_filename == NULL) {
/* Examples:
* "cmd >" (no filename)
* "cmd > <file" (2nd redirect starts too early)
*/
syntax_error("invalid redirect");
continue;
}
mode = redir_table[redir->rd_type].mode;
p = expand_string_to_string(redir->rd_filename,
EXP_FLAG_ESC_GLOB_CHARS, /*unbackslash:*/ 1);
newfd = open_or_warn(p, mode);
free(p);
if (newfd < 0) {
/* Error message from open_or_warn can be lost
* if stderr has been redirected, but bash
* and ash both lose it as well
* (though zsh doesn't!)
*/
return 1;
}
if (newfd == redir->rd_fd && sqp) {
/* open() gave us precisely the fd we wanted.
* This means that this fd was not busy
* (not opened to anywhere).
* Remember to close it on restore:
*/
*sqp = add_squirrel_closed(*sqp, newfd);
debug_printf_redir("redir to previously closed fd %d\n", newfd);
}
} else {
/* "rd_fd>&rd_dup" or "rd_fd>&-" case */
newfd = redir->rd_dup;
}
if (newfd == redir->rd_fd)
continue;
/* if "N>FILE": move newfd to redir->rd_fd */
/* if "N>&M": dup newfd to redir->rd_fd */
/* if "N>&-": close redir->rd_fd (newfd is REDIRFD_CLOSE) */
closed = save_fd_on_redirect(redir->rd_fd, /*avoid:*/ newfd, sqp);
if (newfd == REDIRFD_CLOSE) {
/* "N>&-" means "close me" */
if (!closed) {
/* ^^^ optimization: saving may already
* have closed it. If not... */
close(redir->rd_fd);
}
/* Sometimes we do another close on restore, getting EBADF.
* Consider "echo 3>FILE 3>&-"
* first redirect remembers "need to close 3",
* and second redirect closes 3! Restore code then closes 3 again.
*/
} else {
/* if newfd is a script fd or saved fd, simulate EBADF */
if (internally_opened_fd(newfd, sqp && sqp != ERR_PTR ? *sqp : NULL)) {
//errno = EBADF;
//bb_perror_msg_and_die("can't duplicate file descriptor");
newfd = -1; /* same effect as code above */
}
xdup2(newfd, redir->rd_fd);
if (redir->rd_dup == REDIRFD_TO_FILE)
/* "rd_fd > FILE" */
close(newfd);
/* else: "rd_fd > rd_dup" */
}
}
return 0;
}
static char *find_in_path(const char *arg)
{
char *ret = NULL;
const char *PATH = get_local_var_value("PATH");
if (!PATH)
return NULL;
while (1) {
const char *end = strchrnul(PATH, ':');
int sz = end - PATH; /* must be int! */
free(ret);
if (sz != 0) {
ret = xasprintf("%.*s/%s", sz, PATH, arg);
} else {
/* We have xxx::yyyy in $PATH,
* it means "use current dir" */
ret = xstrdup(arg);
}
if (access(ret, F_OK) == 0)
break;
if (*end == '\0') {
free(ret);
return NULL;
}
PATH = end + 1;
}
return ret;
}
static const struct built_in_command *find_builtin_helper(const char *name,
const struct built_in_command *x,
const struct built_in_command *end)
{
while (x != end) {
if (strcmp(name, x->b_cmd) != 0) {
x++;
continue;
}
debug_printf_exec("found builtin '%s'\n", name);
return x;
}
return NULL;
}
static const struct built_in_command *find_builtin1(const char *name)
{
return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
}
static const struct built_in_command *find_builtin(const char *name)
{
const struct built_in_command *x = find_builtin1(name);
if (x)
return x;
return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
}
static void remove_nested_vars(void)
{
struct variable *cur;
struct variable **cur_pp;
cur_pp = &G.top_var;
while ((cur = *cur_pp) != NULL) {
if (cur->var_nest_level <= G.var_nest_level) {
cur_pp = &cur->next;
continue;
}
/* Unexport */
if (cur->flg_export) {
debug_printf_env("unexporting nested '%s'/%u\n", cur->varstr, cur->var_nest_level);
bb_unsetenv(cur->varstr);
}
/* Remove from global list */
*cur_pp = cur->next;
/* Free */
if (!cur->max_len) {
/* Testcase (interactive):
* f() { local PS1='\w \$ '; }; f
* we should forget local PS1:
*/
handle_changed_special_names(cur->varstr, endofname(cur->varstr) - cur->varstr);
debug_printf_env("freeing nested '%s'/%u\n", cur->varstr, cur->var_nest_level);
free(cur->varstr);
}
free(cur);
}
}
static void enter_var_nest_level(void)
{
G.var_nest_level++;
debug_printf_env("var_nest_level++ %u\n", G.var_nest_level);
/* Try: f() { echo -n .; f; }; f
* struct variable::var_nest_level is uint16_t,
* thus limiting recursion to < 2^16.
* In any case, with 8 Mbyte stack SEGV happens
* not too long after 2^16 recursions anyway.
*/
if (G.var_nest_level > 0xff00)
bb_error_msg_and_die("fatal recursion (depth %u)", G.var_nest_level);
}
static void leave_var_nest_level(void)
{
G.var_nest_level--;
debug_printf_env("var_nest_level-- %u\n", G.var_nest_level);
if (HUSH_DEBUG && (int)G.var_nest_level < 0)
bb_error_msg_and_die("BUG: nesting underflow");
remove_nested_vars();
}
#if ENABLE_HUSH_FUNCTIONS
static struct function **find_function_slot(const char *name)
{
struct function *funcp;
struct function **funcpp = &G.top_func;
while ((funcp = *funcpp) != NULL) {
if (strcmp(name, funcp->name) == 0) {
debug_printf_exec("found function '%s'\n", name);
break;
}
funcpp = &funcp->next;
}
return funcpp;
}
static ALWAYS_INLINE const struct function *find_function(const char *name)
{
const struct function *funcp = *find_function_slot(name);
return funcp;
}
/* Note: takes ownership on name ptr */
static struct function *new_function(char *name)
{
struct function **funcpp = find_function_slot(name);
struct function *funcp = *funcpp;
if (funcp != NULL) {
struct command *cmd = funcp->parent_cmd;
debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
if (!cmd) {
debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
free(funcp->name);
/* Note: if !funcp->body, do not free body_as_string!
* This is a special case of "-F name body" function:
* body_as_string was not malloced! */
if (funcp->body) {
free_pipe_list(funcp->body);
# if !BB_MMU
free(funcp->body_as_string);
# endif
}
} else {
debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
cmd->argv[0] = funcp->name;
cmd->group = funcp->body;
# if !BB_MMU
cmd->group_as_string = funcp->body_as_string;
# endif
}
} else {
debug_printf_exec("remembering new function '%s'\n", name);
funcp = *funcpp = xzalloc(sizeof(*funcp));
/*funcp->next = NULL;*/
}
funcp->name = name;
return funcp;
}
# if ENABLE_HUSH_UNSET
static void unset_func(const char *name)
{
struct function **funcpp = find_function_slot(name);
struct function *funcp = *funcpp;
if (funcp != NULL) {
debug_printf_exec("freeing function '%s'\n", funcp->name);
*funcpp = funcp->next;
/* funcp is unlinked now, deleting it.
* Note: if !funcp->body, the function was created by
* "-F name body", do not free ->body_as_string
* and ->name as they were not malloced. */
if (funcp->body) {
free_pipe_list(funcp->body);
free(funcp->name);
# if !BB_MMU
free(funcp->body_as_string);
# endif
}
free(funcp);
}
}
# endif
# if BB_MMU
#define exec_function(to_free, funcp, argv) \
exec_function(funcp, argv)
# endif
static void exec_function(char ***to_free,
const struct function *funcp,
char **argv) NORETURN;
static void exec_function(char ***to_free,
const struct function *funcp,
char **argv)
{
# if BB_MMU
int n;
argv[0] = G.global_argv[0];
G.global_argv = argv;
G.global_argc = n = 1 + string_array_len(argv + 1);
// Example when we are here: "cmd | func"
// func will run with saved-redirect fds open.
// $ f() { echo /proc/self/fd/*; }
// $ true | f
// /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3
// stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ DIR fd for glob
// Same in script:
// $ . ./SCRIPT
// /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3 /proc/self/fd/4
// stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ opened ./SCRIPT DIR fd for glob
// They are CLOEXEC so external programs won't see them, but
// for "more correctness" we might want to close those extra fds here:
//? close_saved_fds_and_FILE_fds();
/* "we are in a function, ok to use return" */
G_flag_return_in_progress = -1;
enter_var_nest_level();
IF_HUSH_LOCAL(G.func_nest_level++;)
/* On MMU, funcp->body is always non-NULL */
n = run_list(funcp->body);
fflush_all();
_exit(n);
# else
//? close_saved_fds_and_FILE_fds();
//TODO: check whether "true | func_with_return" works
re_execute_shell(to_free,
funcp->body_as_string,
G.global_argv[0],
argv + 1,
NULL);
# endif
}
static int run_function(const struct function *funcp, char **argv)
{
int rc;
save_arg_t sv;
smallint sv_flg;
save_and_replace_G_args(&sv, argv);
/* "We are in function, ok to use return" */
sv_flg = G_flag_return_in_progress;
G_flag_return_in_progress = -1;
/* Make "local" variables properly shadow previous ones */
IF_HUSH_LOCAL(enter_var_nest_level();)
IF_HUSH_LOCAL(G.func_nest_level++;)
/* On MMU, funcp->body is always non-NULL */
# if !BB_MMU
if (!funcp->body) {
/* Function defined by -F */
parse_and_run_string(funcp->body_as_string);
rc = G.last_exitcode;
} else
# endif
{
rc = run_list(funcp->body);
}
IF_HUSH_LOCAL(G.func_nest_level--;)
IF_HUSH_LOCAL(leave_var_nest_level();)
G_flag_return_in_progress = sv_flg;
restore_G_args(&sv, argv);
return rc;
}
#endif /* ENABLE_HUSH_FUNCTIONS */
#if BB_MMU
#define exec_builtin(to_free, x, argv) \
exec_builtin(x, argv)
#else
#define exec_builtin(to_free, x, argv) \
exec_builtin(to_free, argv)
#endif
static void exec_builtin(char ***to_free,
const struct built_in_command *x,
char **argv) NORETURN;
static void exec_builtin(char ***to_free,
const struct built_in_command *x,
char **argv)
{
#if BB_MMU
int rcode;
fflush_all();
//? close_saved_fds_and_FILE_fds();
rcode = x->b_function(argv);
fflush_all();
_exit(rcode);
#else
fflush_all();
/* On NOMMU, we must never block!
* Example: { sleep 99 | read line; } & echo Ok
*/
re_execute_shell(to_free,
argv[0],
G.global_argv[0],
G.global_argv + 1,
argv);
#endif
}
static void execvp_or_die(char **argv) NORETURN;
static void execvp_or_die(char **argv)
{
int e;
debug_printf_exec("execing '%s'\n", argv[0]);
/* Don't propagate SIG_IGN to the child */
if (SPECIAL_JOBSTOP_SIGS != 0)
switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
execvp(argv[0], argv);
e = 2;
if (errno == EACCES) e = 126;
if (errno == ENOENT) e = 127;
bb_perror_msg("can't execute '%s'", argv[0]);
_exit(e);
}
#if ENABLE_HUSH_MODE_X
static void x_mode_print_optionally_squoted(const char *str)
{
unsigned len;
const char *cp;
cp = str;
/* the set of chars which-cause-string-to-be-squoted mimics bash */
/* test a char with: bash -c 'set -x; echo "CH"' */
if (str[strcspn(str, "\\\"'`$(){}[]<>;#&|~*?!^"
" " "\001\002\003\004\005\006\007"
"\010\011\012\013\014\015\016\017"
"\020\021\022\023\024\025\026\027"
"\030\031\032\033\034\035\036\037"
)
] == '\0'
) {
/* string has no special chars */
x_mode_addstr(str);
return;
}
cp = str;
for (;;) {
/* print '....' up to EOL or first squote */
len = (int)(strchrnul(cp, '\'') - cp);
if (len != 0) {
x_mode_addchr('\'');
x_mode_addblock(cp, len);
x_mode_addchr('\'');
cp += len;
}
if (*cp == '\0')
break;
/* string contains squote(s), print them as \' */
x_mode_addchr('\\');
x_mode_addchr('\'');
cp++;
}
}
static void dump_cmd_in_x_mode(char **argv)
{
if (G_x_mode && argv) {
unsigned n;
/* "+[+++...][ cmd...]\n\0" */
x_mode_prefix();
n = 0;
while (argv[n]) {
x_mode_addchr(' ');
if (argv[n][0] == '\0') {
x_mode_addchr('\'');
x_mode_addchr('\'');
} else {
x_mode_print_optionally_squoted(argv[n]);
}
n++;
}
x_mode_flush();
}
}
#else
# define dump_cmd_in_x_mode(argv) ((void)0)
#endif
#if ENABLE_HUSH_COMMAND
static void if_command_vV_print_and_exit(char opt_vV, char *cmd, const char *explanation)
{
char *to_free;
if (!opt_vV)
return;
to_free = NULL;
if (!explanation) {
char *path = getenv("PATH");
explanation = to_free = find_executable(cmd, &path); /* path == NULL is ok */
if (!explanation)
_exit(1); /* PROG was not found */
if (opt_vV != 'V')
cmd = to_free; /* -v PROG prints "/path/to/PROG" */
}
printf((opt_vV == 'V') ? "%s is %s\n" : "%s\n", cmd, explanation);
free(to_free);
fflush_all();
_exit(0);
}
#else
# define if_command_vV_print_and_exit(a,b,c) ((void)0)
#endif
#if BB_MMU
#define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
#define pseudo_exec(nommu_save, command, argv_expanded) \
pseudo_exec(command, argv_expanded)
#endif
/* Called after [v]fork() in run_pipe, or from builtin_exec.
* Never returns.
* Don't exit() here. If you don't exec, use _exit instead.
* The at_exit handlers apparently confuse the calling process,
* in particular stdin handling. Not sure why? -- because of vfork! (vda)
*/
static void pseudo_exec_argv(nommu_save_t *nommu_save,
char **argv, int assignment_cnt,
char **argv_expanded) NORETURN;
static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
char **argv, int assignment_cnt,
char **argv_expanded)
{
const struct built_in_command *x;
struct variable **sv_shadowed;
char **new_env;
IF_HUSH_COMMAND(char opt_vV = 0;)
IF_HUSH_FUNCTIONS(const struct function *funcp;)
new_env = expand_assignments(argv, assignment_cnt);
dump_cmd_in_x_mode(new_env);
if (!argv[assignment_cnt]) {
/* Case when we are here: ... | var=val | ...
* (note that we do not exit early, i.e., do not optimize out
* expand_assignments(): think about ... | var=`sleep 1` | ...
*/
free_strings(new_env);
_exit(EXIT_SUCCESS);
}
sv_shadowed = G.shadowed_vars_pp;
#if BB_MMU
G.shadowed_vars_pp = NULL; /* "don't save, free them instead" */
#else
G.shadowed_vars_pp = &nommu_save->old_vars;
G.var_nest_level++;
#endif
set_vars_and_save_old(new_env);
G.shadowed_vars_pp = sv_shadowed;
if (argv_expanded) {
argv = argv_expanded;
} else {
argv = expand_strvec_to_strvec(argv + assignment_cnt);
#if !BB_MMU
nommu_save->argv = argv;
#endif
}
dump_cmd_in_x_mode(argv);
#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
if (strchr(argv[0], '/') != NULL)
goto skip;
#endif
#if ENABLE_HUSH_FUNCTIONS
/* Check if the command matches any functions (this goes before bltins) */
funcp = find_function(argv[0]);
if (funcp)
exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
#endif
#if ENABLE_HUSH_COMMAND
/* "command BAR": run BAR without looking it up among functions
* "command -v BAR": print "BAR" or "/path/to/BAR"; or exit 1
* "command -V BAR": print "BAR is {a function,a shell builtin,/path/to/BAR}"
*/
while (strcmp(argv[0], "command") == 0 && argv[1]) {
char *p;
argv++;
p = *argv;
if (p[0] != '-' || !p[1])
continue; /* bash allows "command command command [-OPT] BAR" */
for (;;) {
p++;
switch (*p) {
case '\0':
argv++;
p = *argv;
if (p[0] != '-' || !p[1])
goto after_opts;
continue; /* next arg is also -opts, process it too */
case 'v':
case 'V':
opt_vV = *p;
continue;
default:
bb_error_msg_and_die("%s: %s: invalid option", "command", argv[0]);
}
}
}
after_opts:
# if ENABLE_HUSH_FUNCTIONS
if (opt_vV && find_function(argv[0]))
if_command_vV_print_and_exit(opt_vV, argv[0], "a function");
# endif
#endif
/* Check if the command matches any of the builtins.
* Depending on context, this might be redundant. But it's
* easier to waste a few CPU cycles than it is to figure out
* if this is one of those cases.
*/
/* Why "BB_MMU ? :" difference in logic? -
* On NOMMU, it is more expensive to re-execute shell
* just in order to run echo or test builtin.
* It's better to skip it here and run corresponding
* non-builtin later. */
x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
if (x) {
if_command_vV_print_and_exit(opt_vV, argv[0], "a shell builtin");
exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
}
#if ENABLE_FEATURE_SH_STANDALONE
/* Check if the command matches any busybox applets */
{
int a = find_applet_by_name(argv[0]);
if (a >= 0) {
if_command_vV_print_and_exit(opt_vV, argv[0], "an applet");
# if BB_MMU /* see above why on NOMMU it is not allowed */
if (APPLET_IS_NOEXEC(a)) {
/* Do not leak open fds from opened script files etc.
* Testcase: interactive "ls -l /proc/self/fd"
* should not show tty fd open.
*/
close_saved_fds_and_FILE_fds();
//FIXME: should also close saved redir fds
//This casuses test failures in
//redir_children_should_not_see_saved_fd_2.tests
//redir_children_should_not_see_saved_fd_3.tests
//if you replace "busybox find" with just "find" in them
/* Without this, "rm -i FILE" can't be ^C'ed: */
switch_off_special_sigs(G.special_sig_mask);
debug_printf_exec("running applet '%s'\n", argv[0]);
run_noexec_applet_and_exit(a, argv[0], argv);
}
# endif
/* Re-exec ourselves */
debug_printf_exec("re-execing applet '%s'\n", argv[0]);
/* Don't propagate SIG_IGN to the child */
if (SPECIAL_JOBSTOP_SIGS != 0)
switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
execv(bb_busybox_exec_path, argv);
/* If they called chroot or otherwise made the binary no longer
* executable, fall through */
}
}
#endif
#if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
skip:
#endif
if_command_vV_print_and_exit(opt_vV, argv[0], NULL);
execvp_or_die(argv);
}
/* Called after [v]fork() in run_pipe
*/
static void pseudo_exec(nommu_save_t *nommu_save,
struct command *command,
char **argv_expanded) NORETURN;
static void pseudo_exec(nommu_save_t *nommu_save,
struct command *command,
char **argv_expanded)
{
#if ENABLE_HUSH_FUNCTIONS
if (command->cmd_type == CMD_FUNCDEF) {
/* Ignore funcdefs in pipes:
* true | f() { cmd }
*/
_exit(0);
}
#endif
if (command->argv) {
pseudo_exec_argv(nommu_save, command->argv,
command->assignment_cnt, argv_expanded);
}
if (command->group) {
/* Cases when we are here:
* ( list )
* { list } &
* ... | ( list ) | ...
* ... | { list } | ...
*/
#if BB_MMU
int rcode;
debug_printf_exec("pseudo_exec: run_list\n");
reset_traps_to_defaults();
rcode = run_list(command->group);
/* OK to leak memory by not calling free_pipe_list,
* since this process is about to exit */
_exit(rcode);
#else
re_execute_shell(&nommu_save->argv_from_re_execing,
command->group_as_string,
G.global_argv[0],
G.global_argv + 1,
NULL);
#endif
}
/* Case when we are here: ... | >file */
debug_printf_exec("pseudo_exec'ed null command\n");
_exit(EXIT_SUCCESS);
}
#if ENABLE_HUSH_JOB
static const char *get_cmdtext(struct pipe *pi)
{
char **argv;
char *p;
int len;
/* This is subtle. ->cmdtext is created only on first backgrounding.
* (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
* On subsequent bg argv is trashed, but we won't use it */
if (pi->cmdtext)
return pi->cmdtext;
argv = pi->cmds[0].argv;
if (!argv) {
pi->cmdtext = xzalloc(1);
return pi->cmdtext;
}
len = 0;
do {
len += strlen(*argv) + 1;
} while (*++argv);
p = xmalloc(len);
pi->cmdtext = p;
argv = pi->cmds[0].argv;
do {
p = stpcpy(p, *argv);
*p++ = ' ';
} while (*++argv);
p[-1] = '\0';
return pi->cmdtext;
}
static void remove_job_from_table(struct pipe *pi)
{
struct pipe *prev_pipe;
if (pi == G.job_list) {
G.job_list = pi->next;
} else {
prev_pipe = G.job_list;
while (prev_pipe->next != pi)
prev_pipe = prev_pipe->next;
prev_pipe->next = pi->next;
}
G.last_jobid = 0;
if (G.job_list)
G.last_jobid = G.job_list->jobid;
}
static void delete_finished_job(struct pipe *pi)
{
remove_job_from_table(pi);
free_pipe(pi);
}
static void clean_up_last_dead_job(void)
{
if (G.job_list && !G.job_list->alive_cmds)
delete_finished_job(G.job_list);
}
static void insert_job_into_table(struct pipe *pi)
{
struct pipe *job, **jobp;
int i;
clean_up_last_dead_job();
/* Find the end of the list, and find next job ID to use */
i = 0;
jobp = &G.job_list;
while ((job = *jobp) != NULL) {
if (job->jobid > i)
i = job->jobid;
jobp = &job->next;
}
pi->jobid = i + 1;
/* Create a new job struct at the end */
job = *jobp = xmemdup(pi, sizeof(*pi));
job->next = NULL;
job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
/* Cannot copy entire pi->cmds[] vector! This causes double frees */
for (i = 0; i < pi->num_cmds; i++) {
job->cmds[i].pid = pi->cmds[i].pid;
/* all other fields are not used and stay zero */
}
job->cmdtext = xstrdup(get_cmdtext(pi));
if (G_interactive_fd)
printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
G.last_jobid = job->jobid;
}
#endif /* JOB */
static int job_exited_or_stopped(struct pipe *pi)
{
int rcode, i;
if (pi->alive_cmds != pi->stopped_cmds)
return -1;
/* All processes in fg pipe have exited or stopped */
rcode = 0;
i = pi->num_cmds;
while (--i >= 0) {
rcode = pi->cmds[i].cmd_exitcode;
/* usually last process gives overall exitstatus,
* but with "set -o pipefail", last *failed* process does */
if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
break;
}
IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
return rcode;
}
static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
{
#if ENABLE_HUSH_JOB
struct pipe *pi;
#endif
int i, dead;
dead = WIFEXITED(status) || WIFSIGNALED(status);
#if DEBUG_JOBS
if (WIFSTOPPED(status))
debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
childpid, WSTOPSIG(status), WEXITSTATUS(status));
if (WIFSIGNALED(status))
debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
childpid, WTERMSIG(status), WEXITSTATUS(status));
if (WIFEXITED(status))
debug_printf_jobs("pid %d exited, exitcode %d\n",
childpid, WEXITSTATUS(status));
#endif
/* Were we asked to wait for a fg pipe? */
if (fg_pipe) {
i = fg_pipe->num_cmds;
while (--i >= 0) {
int rcode;
debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
if (fg_pipe->cmds[i].pid != childpid)
continue;
if (dead) {
int ex;
fg_pipe->cmds[i].pid = 0;
fg_pipe->alive_cmds--;
ex = WEXITSTATUS(status);
/* bash prints killer signal's name for *last*
* process in pipe (prints just newline for SIGINT/SIGPIPE).
* Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
*/
if (WIFSIGNALED(status)) {
int sig = WTERMSIG(status);
if (i == fg_pipe->num_cmds-1)
/* TODO: use strsignal() instead for bash compat? but that's bloat... */
puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
/* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
/* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
* Maybe we need to use sig | 128? */
ex = sig + 128;
}
fg_pipe->cmds[i].cmd_exitcode = ex;
} else {
fg_pipe->stopped_cmds++;
}
debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
rcode = job_exited_or_stopped(fg_pipe);
if (rcode >= 0) {
/* Note: *non-interactive* bash does not continue if all processes in fg pipe
* are stopped. Testcase: "cat | cat" in a script (not on command line!)
* and "killall -STOP cat" */
if (G_interactive_fd) {
#if ENABLE_HUSH_JOB
if (fg_pipe->alive_cmds != 0)
insert_job_into_table(fg_pipe);
#endif
return rcode;
}
if (fg_pipe->alive_cmds == 0)
return rcode;
}
/* There are still running processes in the fg_pipe */
return -1;
}
/* It wasn't in fg_pipe, look for process in bg pipes */
}
#if ENABLE_HUSH_JOB
/* We were asked to wait for bg or orphaned children */
/* No need to remember exitcode in this case */
for (pi = G.job_list; pi; pi = pi->next) {
for (i = 0; i < pi->num_cmds; i++) {
if (pi->cmds[i].pid == childpid)
goto found_pi_and_prognum;
}
}
/* Happens when shell is used as init process (init=/bin/sh) */
debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
return -1; /* this wasn't a process from fg_pipe */
found_pi_and_prognum:
if (dead) {
/* child exited */
int rcode = WEXITSTATUS(status);
if (WIFSIGNALED(status))
rcode = 128 + WTERMSIG(status);
pi->cmds[i].cmd_exitcode = rcode;
if (G.last_bg_pid == pi->cmds[i].pid)
G.last_bg_pid_exitcode = rcode;
pi->cmds[i].pid = 0;
pi->alive_cmds--;
if (!pi->alive_cmds) {
#if ENABLE_HUSH_BASH_COMPAT
G.dead_job_exitcode = job_exited_or_stopped(pi);
#endif
if (G_interactive_fd) {
printf(JOB_STATUS_FORMAT, pi->jobid,
"Done", pi->cmdtext);
delete_finished_job(pi);
} else {
/*
* bash deletes finished jobs from job table only in interactive mode,
* after "jobs" cmd, or if pid of a new process matches one of the old ones
* (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
* Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
* We only retain one "dead" job, if it's the single job on the list.
* This covers most of real-world scenarios where this is useful.
*/
if (pi != G.job_list)
delete_finished_job(pi);
}
}
} else {
/* child stopped */
pi->stopped_cmds++;
}
#endif
return -1; /* this wasn't a process from fg_pipe */
}
/* Check to see if any processes have exited -- if they have,
* figure out why and see if a job has completed.
*
* If non-NULL fg_pipe: wait for its completion or stop.
* Return its exitcode or zero if stopped.
*
* Alternatively (fg_pipe == NULL, waitfor_pid != 0):
* waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
* else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
* or 0 if no children changed status.
*
* Alternatively (fg_pipe == NULL, waitfor_pid == 0),
* return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
* or 0 if no children changed status.
*/
static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
{
int attributes;
int status;
int rcode = 0;
debug_printf_jobs("checkjobs %p\n", fg_pipe);
attributes = WUNTRACED;
if (fg_pipe == NULL)
attributes |= WNOHANG;
errno = 0;
#if ENABLE_HUSH_FAST
if (G.handled_SIGCHLD == G.count_SIGCHLD) {
//bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
//getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
/* There was neither fork nor SIGCHLD since last waitpid */
/* Avoid doing waitpid syscall if possible */
if (!G.we_have_children) {
errno = ECHILD;
return -1;
}
if (fg_pipe == NULL) { /* is WNOHANG set? */
/* We have children, but they did not exit
* or stop yet (we saw no SIGCHLD) */
return 0;
}
/* else: !WNOHANG, waitpid will block, can't short-circuit */
}
#endif
/* Do we do this right?
* bash-3.00# sleep 20 | false
* <ctrl-Z pressed>
* [3]+ Stopped sleep 20 | false
* bash-3.00# echo $?
* 1 <========== bg pipe is not fully done, but exitcode is already known!
* [hush 1.14.0: yes we do it right]
*/
while (1) {
pid_t childpid;
#if ENABLE_HUSH_FAST
int i;
i = G.count_SIGCHLD;
#endif
childpid = waitpid(-1, &status, attributes);
if (childpid <= 0) {
if (childpid && errno != ECHILD)
bb_perror_msg("waitpid");
#if ENABLE_HUSH_FAST
else { /* Until next SIGCHLD, waitpid's are useless */
G.we_have_children = (childpid == 0);
G.handled_SIGCHLD = i;
//bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
}
#endif
/* ECHILD (no children), or 0 (no change in children status) */
rcode = childpid;
break;
}
rcode = process_wait_result(fg_pipe, childpid, status);
if (rcode >= 0) {
/* fg_pipe exited or stopped */
break;
}
if (childpid == waitfor_pid) { /* "wait PID" */
debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
rcode = WEXITSTATUS(status);
if (WIFSIGNALED(status))
rcode = 128 + WTERMSIG(status);
if (WIFSTOPPED(status))
/* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
rcode = 128 + WSTOPSIG(status);
rcode++;
break; /* "wait PID" called us, give it exitcode+1 */
}
#if ENABLE_HUSH_BASH_COMPAT
if (-1 == waitfor_pid /* "wait -n" (wait for any one job) */
&& G.dead_job_exitcode >= 0 /* some job did finish */
) {
debug_printf_exec("waitfor_pid:-1\n");
rcode = G.dead_job_exitcode + 1;
break;
}
#endif
/* This wasn't one of our processes, or */
/* fg_pipe still has running processes, do waitpid again */
} /* while (waitpid succeeds)... */
return rcode;
}
#if ENABLE_HUSH_JOB
static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
{
pid_t p;
int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
if (G_saved_tty_pgrp) {
/* Job finished, move the shell to the foreground */
p = getpgrp(); /* our process group id */
debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
tcsetpgrp(G_interactive_fd, p);
}
return rcode;
}
#endif
/* Start all the jobs, but don't wait for anything to finish.
* See checkjobs().
*
* Return code is normally -1, when the caller has to wait for children
* to finish to determine the exit status of the pipe. If the pipe
* is a simple builtin command, however, the action is done by the
* time run_pipe returns, and the exit code is provided as the
* return value.
*
* Returns -1 only if started some children. IOW: we have to
* mask out retvals of builtins etc with 0xff!
*
* The only case when we do not need to [v]fork is when the pipe
* is single, non-backgrounded, non-subshell command. Examples:
* cmd ; ... { list } ; ...
* cmd && ... { list } && ...
* cmd || ... { list } || ...
* If it is, then we can run cmd as a builtin, NOFORK,
* or (if SH_STANDALONE) an applet, and we can run the { list }
* with run_list. If it isn't one of these, we fork and exec cmd.
*
* Cases when we must fork:
* non-single: cmd | cmd
* backgrounded: cmd & { list } &
* subshell: ( list ) [&]
*/
#if !ENABLE_HUSH_MODE_X
#define redirect_and_varexp_helper(command, sqp, argv_expanded) \
redirect_and_varexp_helper(command, sqp)
#endif
static int redirect_and_varexp_helper(
struct command *command,
struct squirrel **sqp,
char **argv_expanded)
{
/* Assignments occur before redirects. Try:
* a=`sleep 1` sleep 2 3>/qwe/rty
*/
char **new_env = expand_assignments(command->argv, command->assignment_cnt);
dump_cmd_in_x_mode(new_env);
dump_cmd_in_x_mode(argv_expanded);
/* this takes ownership of new_env[i] elements, and frees new_env: */
set_vars_and_save_old(new_env);
return setup_redirects(command, sqp);
}
static NOINLINE int run_pipe(struct pipe *pi)
{
static const char *const null_ptr = NULL;
int cmd_no;
int next_infd;
struct command *command;
char **argv_expanded;
char **argv;
struct squirrel *squirrel = NULL;
int rcode;
debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
debug_enter();
/* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
* Result should be 3 lines: q w e, qwe, q w e
*/
if (G.ifs_whitespace != G.ifs)
free(G.ifs_whitespace);
G.ifs = get_local_var_value("IFS");
if (G.ifs) {
char *p;
G.ifs_whitespace = (char*)G.ifs;
p = skip_whitespace(G.ifs);
if (*p) {
/* Not all $IFS is whitespace */
char *d;
int len = p - G.ifs;
p = skip_non_whitespace(p);
G.ifs_whitespace = xmalloc(len + strlen(p) + 1); /* can overestimate */
d = mempcpy(G.ifs_whitespace, G.ifs, len);
while (*p) {
if (isspace(*p))
*d++ = *p;
p++;
}
*d = '\0';
}
} else {
G.ifs = defifs;
G.ifs_whitespace = (char*)G.ifs;
}
IF_HUSH_JOB(pi->pgrp = -1;)
pi->stopped_cmds = 0;
command = &pi->cmds[0];
argv_expanded = NULL;
if (pi->num_cmds != 1
|| pi->followup == PIPE_BG
|| command->cmd_type == CMD_SUBSHELL
) {
goto must_fork;
}
pi->alive_cmds = 1;
debug_printf_exec(": group:%p argv:'%s'\n",
command->group, command->argv ? command->argv[0] : "NONE");
if (command->group) {
#if ENABLE_HUSH_FUNCTIONS
if (command->cmd_type == CMD_FUNCDEF) {
/* "executing" func () { list } */
struct function *funcp;
funcp = new_function(command->argv[0]);
/* funcp->name is already set to argv[0] */
funcp->body = command->group;
# if !BB_MMU
funcp->body_as_string = command->group_as_string;
command->group_as_string = NULL;
# endif
command->group = NULL;
command->argv[0] = NULL;
debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
funcp->parent_cmd = command;
command->child_func = funcp;
debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
debug_leave();
return EXIT_SUCCESS;
}
#endif
/* { list } */
debug_printf_exec("non-subshell group\n");
rcode = 1; /* exitcode if redir failed */
if (setup_redirects(command, &squirrel) == 0) {
debug_printf_exec(": run_list\n");
//FIXME: we need to pass squirrel down into run_list()
//for SH_STANDALONE case, or else this construct:
// { find /proc/self/fd; true; } >FILE; cmd2
//has no way of closing saved fd#1 for "find",
//and in SH_STANDALONE mode, "find" is not execed,
//therefore CLOEXEC on saved fd does not help.
rcode = run_list(command->group) & 0xff;
}
restore_redirects(squirrel);
IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
debug_leave();
debug_printf_exec("run_pipe: return %d\n", rcode);
return rcode;
}
argv = command->argv ? command->argv : (char **) &null_ptr;
{
const struct built_in_command *x;
IF_HUSH_FUNCTIONS(const struct function *funcp;)
IF_NOT_HUSH_FUNCTIONS(enum { funcp = 0 };)
struct variable **sv_shadowed;
struct variable *old_vars;
#if ENABLE_HUSH_LINENO_VAR
if (G.lineno_var)
strcpy(G.lineno_var + sizeof("LINENO=")-1, utoa(command->lineno));
#endif
if (argv[command->assignment_cnt] == NULL) {
/* Assignments, but no command.
* Ensure redirects take effect (that is, create files).
* Try "a=t >file"
*/
unsigned i;
G.expand_exitcode = 0;
only_assignments:
rcode = setup_redirects(command, &squirrel);
restore_redirects(squirrel);
/* Set shell variables */
i = 0;
while (i < command->assignment_cnt) {
char *p = expand_string_to_string(argv[i],
EXP_FLAG_ESC_GLOB_CHARS,
/*unbackslash:*/ 1
);
#if ENABLE_HUSH_MODE_X
if (G_x_mode) {
char *eq;
if (i == 0)
x_mode_prefix();
x_mode_addchr(' ');
eq = strchrnul(p, '=');
if (*eq) eq++;
x_mode_addblock(p, (eq - p));
x_mode_print_optionally_squoted(eq);
x_mode_flush();
}
#endif
debug_printf_env("set shell var:'%s'->'%s'\n", *argv, p);
if (set_local_var(p, /*flag:*/ 0)) {
/* assignment to readonly var / putenv error? */
rcode = 1;
}
i++;
}
/* Redirect error sets $? to 1. Otherwise,
* if evaluating assignment value set $?, retain it.
* Else, clear $?:
* false; q=`exit 2`; echo $? - should print 2
* false; x=1; echo $? - should print 0
* Because of the 2nd case, we can't just use G.last_exitcode.
*/
if (rcode == 0)
rcode = G.expand_exitcode;
IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
debug_leave();
debug_printf_exec("run_pipe: return %d\n", rcode);
return rcode;
}
/* Expand the rest into (possibly) many strings each */
#if defined(CMD_SINGLEWORD_NOGLOB)
if (command->cmd_type == CMD_SINGLEWORD_NOGLOB)
argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
else
#endif
argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
/* If someone gives us an empty string: `cmd with empty output` */
if (!argv_expanded[0]) {
free(argv_expanded);
/* `false` still has to set exitcode 1 */
G.expand_exitcode = G.last_exitcode;
goto only_assignments;
}
old_vars = NULL;
sv_shadowed = G.shadowed_vars_pp;
/* Check if argv[0] matches any functions (this goes before bltins) */
IF_HUSH_FUNCTIONS(funcp = find_function(argv_expanded[0]);)
IF_HUSH_FUNCTIONS(x = NULL;)
IF_HUSH_FUNCTIONS(if (!funcp))
x = find_builtin(argv_expanded[0]);
if (x || funcp) {
if (x && x->b_function == builtin_exec && argv_expanded[1] == NULL) {
debug_printf("exec with redirects only\n");
/*
* Variable assignments are executed, but then "forgotten":
* a=`sleep 1;echo A` exec 3>&-; echo $a
* sleeps, but prints nothing.
*/
enter_var_nest_level();
G.shadowed_vars_pp = &old_vars;
rcode = redirect_and_varexp_helper(command,
/*squirrel:*/ ERR_PTR,
argv_expanded
);
G.shadowed_vars_pp = sv_shadowed;
/* rcode=1 can be if redir file can't be opened */
goto clean_up_and_ret1;
}
/* Bump var nesting, or this will leak exported $a:
* a=b true; env | grep ^a=
*/
enter_var_nest_level();
/* Collect all variables "shadowed" by helper
* (IOW: old vars overridden by "var1=val1 var2=val2 cmd..." syntax)
* into old_vars list:
*/
G.shadowed_vars_pp = &old_vars;
rcode = redirect_and_varexp_helper(command, &squirrel, argv_expanded);
if (rcode == 0) {
if (!funcp) {
/* Do not collect *to old_vars list* vars shadowed
* by e.g. "local VAR" builtin (collect them
* in the previously nested list instead):
* don't want them to be restored immediately
* after "local" completes.
*/
G.shadowed_vars_pp = sv_shadowed;
debug_printf_exec(": builtin '%s' '%s'...\n",
x->b_cmd, argv_expanded[1]);
fflush_all();
rcode = x->b_function(argv_expanded) & 0xff;
fflush_all();
}
#if ENABLE_HUSH_FUNCTIONS
else {
debug_printf_exec(": function '%s' '%s'...\n",
funcp->name, argv_expanded[1]);
rcode = run_function(funcp, argv_expanded) & 0xff;
/*
* But do collect *to old_vars list* vars shadowed
* within function execution. To that end, restore
* this pointer _after_ function run:
*/
G.shadowed_vars_pp = sv_shadowed;
}
#endif
}
} else
if (ENABLE_FEATURE_SH_NOFORK && NUM_APPLETS > 1) {
int n = find_applet_by_name(argv_expanded[0]);
if (n < 0 || !APPLET_IS_NOFORK(n))
goto must_fork;
enter_var_nest_level();
/* Collect all variables "shadowed" by helper into old_vars list */
G.shadowed_vars_pp = &old_vars;
rcode = redirect_and_varexp_helper(command, &squirrel, argv_expanded);
G.shadowed_vars_pp = sv_shadowed;
if (rcode == 0) {
debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
argv_expanded[0], argv_expanded[1]);
/*
* Note: signals (^C) can't interrupt here.
* We remember them and they will be acted upon
* after applet returns.
* This makes applets which can run for a long time
* and/or wait for user input ineligible for NOFORK:
* for example, "yes" or "rm" (rm -i waits for input).
*/
rcode = run_nofork_applet(n, argv_expanded);
}
} else
goto must_fork;
restore_redirects(squirrel);
clean_up_and_ret1:
leave_var_nest_level();
add_vars(old_vars);
/*
* Try "usleep 99999999" + ^C + "echo $?"
* with FEATURE_SH_NOFORK=y.
*/
if (!funcp) {
/* It was builtin or nofork.
* if this would be a real fork/execed program,
* it should have died if a fatal sig was received.
* But OTOH, there was no separate process,
* the sig was sent to _shell_, not to non-existing
* child.
* Let's just handle ^C only, this one is obvious:
* we aren't ok with exitcode 0 when ^C was pressed
* during builtin/nofork.
*/
if (sigismember(&G.pending_set, SIGINT))
rcode = 128 + SIGINT;
}
free(argv_expanded);
IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
debug_leave();
debug_printf_exec("run_pipe return %d\n", rcode);
return rcode;
}
must_fork:
/* NB: argv_expanded may already be created, and that
* might include `cmd` runs! Do not rerun it! We *must*
* use argv_expanded if it's non-NULL */
/* Going to fork a child per each pipe member */
pi->alive_cmds = 0;
next_infd = 0;
cmd_no = 0;
while (cmd_no < pi->num_cmds) {
struct fd_pair pipefds;
#if !BB_MMU
int sv_var_nest_level = G.var_nest_level;
volatile nommu_save_t nommu_save;
nommu_save.old_vars = NULL;
nommu_save.argv = NULL;
nommu_save.argv_from_re_execing = NULL;
#endif
command = &pi->cmds[cmd_no];
cmd_no++;
if (command->argv) {
debug_printf_exec(": pipe member '%s' '%s'...\n",
command->argv[0], command->argv[1]);
} else {
debug_printf_exec(": pipe member with no argv\n");
}
/* pipes are inserted between pairs of commands */
pipefds.rd = 0;
pipefds.wr = 1;
if (cmd_no < pi->num_cmds)
xpiped_pair(pipefds);
#if ENABLE_HUSH_LINENO_VAR
if (G.lineno_var)
strcpy(G.lineno_var + sizeof("LINENO=")-1, utoa(command->lineno));
#endif
command->pid = BB_MMU ? fork() : vfork();
if (!command->pid) { /* child */
#if ENABLE_HUSH_JOB
disable_restore_tty_pgrp_on_exit();
CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
/* Every child adds itself to new process group
* with pgid == pid_of_first_child_in_pipe */
if (G.run_list_level == 1 && G_interactive_fd) {
pid_t pgrp;
pgrp = pi->pgrp;
if (pgrp < 0) /* true for 1st process only */
pgrp = getpid();
if (setpgid(0, pgrp) == 0
&& pi->followup != PIPE_BG
&& G_saved_tty_pgrp /* we have ctty */
) {
/* We do it in *every* child, not just first,
* to avoid races */
tcsetpgrp(G_interactive_fd, pgrp);
}
}
#endif
if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
/* 1st cmd in backgrounded pipe
* should have its stdin /dev/null'ed */
close(0);
if (open(bb_dev_null, O_RDONLY))
xopen("/", O_RDONLY);
} else {
xmove_fd(next_infd, 0);
}
xmove_fd(pipefds.wr, 1);
if (pipefds.rd > 1)
close(pipefds.rd);
/* Like bash, explicit redirects override pipes,
* and the pipe fd (fd#1) is available for dup'ing:
* "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
* of cmd1 goes into pipe.
*/
if (setup_redirects(command, NULL)) {
/* Happens when redir file can't be opened:
* $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
* FOO
* hush: can't open '/qwe/rty': No such file or directory
* BAZ
* (echo BAR is not executed, it hits _exit(1) below)
*/
_exit(1);
}
/* Stores to nommu_save list of env vars putenv'ed
* (NOMMU, on MMU we don't need that) */
/* cast away volatility... */
pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
/* pseudo_exec() does not return */
}
/* parent or error */
#if ENABLE_HUSH_FAST
G.count_SIGCHLD++;
//bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
#endif
enable_restore_tty_pgrp_on_exit();
#if !BB_MMU
/* Clean up after vforked child */
free(nommu_save.argv);
free(nommu_save.argv_from_re_execing);
G.var_nest_level = sv_var_nest_level;
remove_nested_vars();
add_vars(nommu_save.old_vars);
#endif
free(argv_expanded);
argv_expanded = NULL;
if (command->pid < 0) { /* [v]fork failed */
/* Clearly indicate, was it fork or vfork */
bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
} else {
pi->alive_cmds++;
#if ENABLE_HUSH_JOB
/* Second and next children need to know pid of first one */
if (pi->pgrp < 0)
pi->pgrp = command->pid;
#endif
}
if (cmd_no > 1)
close(next_infd);
if (cmd_no < pi->num_cmds)
close(pipefds.wr);
/* Pass read (output) pipe end to next iteration */
next_infd = pipefds.rd;
}
if (!pi->alive_cmds) {
debug_leave();
debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
return 1;
}
debug_leave();
debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
return -1;
}
/* NB: called by pseudo_exec, and therefore must not modify any
* global data until exec/_exit (we can be a child after vfork!) */
static int run_list(struct pipe *pi)
{
#if ENABLE_HUSH_CASE
char *case_word = NULL;
#endif
#if ENABLE_HUSH_LOOPS
struct pipe *loop_top = NULL;
char **for_lcur = NULL;
char **for_list = NULL;
#endif
smallint last_followup;
smalluint rcode;
#if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
smalluint cond_code = 0;
#else
enum { cond_code = 0 };
#endif
#if HAS_KEYWORDS
smallint rword; /* RES_foo */
smallint last_rword; /* ditto */
#endif
debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
debug_enter();
#if ENABLE_HUSH_LOOPS
/* Check syntax for "for" */
{
struct pipe *cpipe;
for (cpipe = pi; cpipe; cpipe = cpipe->next) {
if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
continue;
/* current word is FOR or IN (BOLD in comments below) */
if (cpipe->next == NULL) {
syntax_error("malformed for");
debug_leave();
debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
return 1;
}
/* "FOR v; do ..." and "for v IN a b; do..." are ok */
if (cpipe->next->res_word == RES_DO)
continue;
/* next word is not "do". It must be "in" then ("FOR v in ...") */
if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
|| cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
) {
syntax_error("malformed for");
debug_leave();
debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
return 1;
}
}
}
#endif
/* Past this point, all code paths should jump to ret: label
* in order to return, no direct "return" statements please.
* This helps to ensure that no memory is leaked. */
#if ENABLE_HUSH_JOB
G.run_list_level++;
#endif
#if HAS_KEYWORDS
rword = RES_NONE;
last_rword = RES_XXXX;
#endif
last_followup = PIPE_SEQ;
rcode = G.last_exitcode;
/* Go through list of pipes, (maybe) executing them. */
for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
int r;
int sv_errexit_depth;
if (G.flag_SIGINT)
break;
if (G_flag_return_in_progress == 1)
break;
IF_HAS_KEYWORDS(rword = pi->res_word;)
debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
rword, cond_code, last_rword);
sv_errexit_depth = G.errexit_depth;
if (
#if ENABLE_HUSH_IF
rword == RES_IF || rword == RES_ELIF ||
#endif
pi->followup != PIPE_SEQ
) {
G.errexit_depth++;
}
#if ENABLE_HUSH_LOOPS
if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
&& loop_top == NULL /* avoid bumping G.depth_of_loop twice */
) {
/* start of a loop: remember where loop starts */
loop_top = pi;
G.depth_of_loop++;
}
#endif
/* Still in the same "if...", "then..." or "do..." branch? */
if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
if ((rcode == 0 && last_followup == PIPE_OR)
|| (rcode != 0 && last_followup == PIPE_AND)
) {
/* It is "<true> || CMD" or "<false> && CMD"
* and we should not execute CMD */
debug_printf_exec("skipped cmd because of || or &&\n");
last_followup = pi->followup;
goto dont_check_jobs_but_continue;
}
}
last_followup = pi->followup;
IF_HAS_KEYWORDS(last_rword = rword;)
#if ENABLE_HUSH_IF
if (cond_code) {
if (rword == RES_THEN) {
/* if false; then ... fi has exitcode 0! */
G.last_exitcode = rcode = EXIT_SUCCESS;
/* "if <false> THEN cmd": skip cmd */
continue;
}
} else {
if (rword == RES_ELSE || rword == RES_ELIF) {
/* "if <true> then ... ELSE/ELIF cmd":
* skip cmd and all following ones */
break;
}
}
#endif
#if ENABLE_HUSH_LOOPS
if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
if (!for_lcur) {
/* first loop through for */
static const char encoded_dollar_at[] ALIGN1 = {
SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
}; /* encoded representation of "$@" */
static const char *const encoded_dollar_at_argv[] = {
encoded_dollar_at, NULL
}; /* argv list with one element: "$@" */
char **vals;
G.last_exitcode = rcode = EXIT_SUCCESS;
vals = (char**)encoded_dollar_at_argv;
if (pi->next->res_word == RES_IN) {
/* if no variable values after "in" we skip "for" */
if (!pi->next->cmds[0].argv) {
debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
break;
}
vals = pi->next->cmds[0].argv;
} /* else: "for var; do..." -> assume "$@" list */
/* create list of variable values */
debug_print_strings("for_list made from", vals);
for_list = expand_strvec_to_strvec(vals);
for_lcur = for_list;
debug_print_strings("for_list", for_list);
}
if (!*for_lcur) {
/* "for" loop is over, clean up */
free(for_list);
for_list = NULL;
for_lcur = NULL;
break;
}
/* Insert next value from for_lcur */
/* note: *for_lcur already has quotes removed, $var expanded, etc */
set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
continue;
}
if (rword == RES_IN) {
continue; /* "for v IN list;..." - "in" has no cmds anyway */
}
if (rword == RES_DONE) {
continue; /* "done" has no cmds too */
}
#endif
#if ENABLE_HUSH_CASE
if (rword == RES_CASE) {
debug_printf_exec("CASE cond_code:%d\n", cond_code);
case_word = expand_string_to_string(pi->cmds->argv[0],
EXP_FLAG_ESC_GLOB_CHARS, /*unbackslash:*/ 1);
debug_printf_exec("CASE word1:'%s'\n", case_word);
//unbackslash(case_word);
//debug_printf_exec("CASE word2:'%s'\n", case_word);
continue;
}
if (rword == RES_MATCH) {
char **argv;
debug_printf_exec("MATCH cond_code:%d\n", cond_code);
if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
break;
/* all prev words didn't match, does this one match? */
argv = pi->cmds->argv;
while (*argv) {
char *pattern;
debug_printf_exec("expand_string_to_string('%s')\n", *argv);
pattern = expand_string_to_string(*argv,
EXP_FLAG_ESC_GLOB_CHARS,
/*unbackslash:*/ 0
);
/* TODO: which FNM_xxx flags to use? */
cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n",
pattern, case_word, cond_code);
free(pattern);
if (cond_code == 0) {
/* match! we will execute this branch */
free(case_word);
case_word = NULL; /* make future "word)" stop */
break;
}
argv++;
}
continue;
}
if (rword == RES_CASE_BODY) { /* inside of a case branch */
debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
if (cond_code != 0)
continue; /* not matched yet, skip this pipe */
}
if (rword == RES_ESAC) {
debug_printf_exec("ESAC cond_code:%d\n", cond_code);
if (case_word) {
/* "case" did not match anything: still set $? (to 0) */
G.last_exitcode = rcode = EXIT_SUCCESS;
}
}
#endif
/* Just pressing <enter> in shell should check for jobs.
* OTOH, in non-interactive shell this is useless
* and only leads to extra job checks */
if (pi->num_cmds == 0) {
if (G_interactive_fd)
goto check_jobs_and_continue;
continue;
}
/* After analyzing all keywords and conditions, we decided
* to execute this pipe. NB: have to do checkjobs(NULL)
* after run_pipe to collect any background children,
* even if list execution is to be stopped. */
debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
#if ENABLE_HUSH_LOOPS
G.flag_break_continue = 0;
#endif
rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
if (r != -1) {
/* We ran a builtin, function, or group.
* rcode is already known
* and we don't need to wait for anything. */
debug_printf_exec(": builtin/func exitcode %d\n", rcode);
G.last_exitcode = rcode;
check_and_run_traps();
#if ENABLE_HUSH_LOOPS
/* Was it "break" or "continue"? */
if (G.flag_break_continue) {
smallint fbc = G.flag_break_continue;
/* We might fall into outer *loop*,
* don't want to break it too */
if (loop_top) {
G.depth_break_continue--;
if (G.depth_break_continue == 0)
G.flag_break_continue = 0;
/* else: e.g. "continue 2" should *break* once, *then* continue */
} /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
checkjobs(NULL, 0 /*(no pid to wait for)*/);
break;
}
/* "continue": simulate end of loop */
rword = RES_DONE;
continue;
}
#endif
if (G_flag_return_in_progress == 1) {
checkjobs(NULL, 0 /*(no pid to wait for)*/);
break;
}
} else if (pi->followup == PIPE_BG) {
/* What does bash do with attempts to background builtins? */
/* even bash 3.2 doesn't do that well with nested bg:
* try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
* I'm NOT treating inner &'s as jobs */
#if ENABLE_HUSH_JOB
if (G.run_list_level == 1)
insert_job_into_table(pi);
#endif
/* Last command's pid goes to $! */
G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
G.last_bg_pid_exitcode = 0;
debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
/* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash say 0 */
rcode = EXIT_SUCCESS;
goto check_traps;
} else {
#if ENABLE_HUSH_JOB
if (G.run_list_level == 1 && G_interactive_fd) {
/* Waits for completion, then fg's main shell */
rcode = checkjobs_and_fg_shell(pi);
debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
goto check_traps;
}
#endif
/* This one just waits for completion */
rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
debug_printf_exec(": checkjobs exitcode %d\n", rcode);
check_traps:
G.last_exitcode = rcode;
check_and_run_traps();
}
/* Handle "set -e" */
if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
if (G.errexit_depth == 0)
hush_exit(rcode);
}
G.errexit_depth = sv_errexit_depth;
/* Analyze how result affects subsequent commands */
#if ENABLE_HUSH_IF
if (rword == RES_IF || rword == RES_ELIF)
cond_code = rcode;
#endif
check_jobs_and_continue:
checkjobs(NULL, 0 /*(no pid to wait for)*/);
dont_check_jobs_but_continue: ;
#if ENABLE_HUSH_LOOPS
/* Beware of "while false; true; do ..."! */
if (pi->next
&& (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
/* check for RES_DONE is needed for "while ...; do \n done" case */
) {
if (rword == RES_WHILE) {
if (rcode) {
/* "while false; do...done" - exitcode 0 */
G.last_exitcode = rcode = EXIT_SUCCESS;
debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
break;
}
}
if (rword == RES_UNTIL) {
if (!rcode) {
debug_printf_exec(": until expr is true: breaking\n");
break;
}
}
}
#endif
} /* for (pi) */
#if ENABLE_HUSH_JOB
G.run_list_level--;
#endif
#if ENABLE_HUSH_LOOPS
if (loop_top)
G.depth_of_loop--;
free(for_list);
#endif
#if ENABLE_HUSH_CASE
free(case_word);
#endif
debug_leave();
debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
return rcode;
}
/* Select which version we will use */
static int run_and_free_list(struct pipe *pi)
{
int rcode = 0;
debug_printf_exec("run_and_free_list entered\n");
if (!G.o_opt[OPT_O_NOEXEC]) {
debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
rcode = run_list(pi);
}
/* free_pipe_list has the side effect of clearing memory.
* In the long run that function can be merged with run_list,
* but doing that now would hobble the debugging effort. */
free_pipe_list(pi);
debug_printf_exec("run_and_free_list return %d\n", rcode);
return rcode;
}
static void install_sighandlers(unsigned mask)
{
sighandler_t old_handler;
unsigned sig = 0;
while ((mask >>= 1) != 0) {
sig++;
if (!(mask & 1))
continue;
old_handler = install_sighandler(sig, pick_sighandler(sig));
/* POSIX allows shell to re-enable SIGCHLD
* even if it was SIG_IGN on entry.
* Therefore we skip IGN check for it:
*/
if (sig == SIGCHLD)
continue;
/* bash re-enables SIGHUP which is SIG_IGNed on entry.
* Try: "trap '' HUP; bash; echo RET" and type "kill -HUP $$"
*/
//if (sig == SIGHUP) continue; - TODO?
if (old_handler == SIG_IGN) {
/* oops... restore back to IGN, and record this fact */
install_sighandler(sig, old_handler);
#if ENABLE_HUSH_TRAP
if (!G_traps)
G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
free(G_traps[sig]);
G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
#endif
}
}
}
/* Called a few times only (or even once if "sh -c") */
static void install_special_sighandlers(void)
{
unsigned mask;
/* Which signals are shell-special? */
mask = (1 << SIGQUIT) | (1 << SIGCHLD);
if (G_interactive_fd) {
mask |= SPECIAL_INTERACTIVE_SIGS;
if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
mask |= SPECIAL_JOBSTOP_SIGS;
}
/* Careful, do not re-install handlers we already installed */
if (G.special_sig_mask != mask) {
unsigned diff = mask & ~G.special_sig_mask;
G.special_sig_mask = mask;
install_sighandlers(diff);
}
}
#if ENABLE_HUSH_JOB
/* helper */
/* Set handlers to restore tty pgrp and exit */
static void install_fatal_sighandlers(void)
{
unsigned mask;
/* We will restore tty pgrp on these signals */
mask = 0
/*+ (1 << SIGILL ) * HUSH_DEBUG*/
/*+ (1 << SIGFPE ) * HUSH_DEBUG*/
+ (1 << SIGBUS ) * HUSH_DEBUG
+ (1 << SIGSEGV) * HUSH_DEBUG
/*+ (1 << SIGTRAP) * HUSH_DEBUG*/
+ (1 << SIGABRT)
/* bash 3.2 seems to handle these just like 'fatal' ones */
+ (1 << SIGPIPE)
+ (1 << SIGALRM)
/* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
* if we aren't interactive... but in this case
* we never want to restore pgrp on exit, and this fn is not called
*/
/*+ (1 << SIGHUP )*/
/*+ (1 << SIGTERM)*/
/*+ (1 << SIGINT )*/
;
G_fatal_sig_mask = mask;
install_sighandlers(mask);
}
#endif
static int set_mode(int state, char mode, const char *o_opt)
{
int idx;
switch (mode) {
case 'n':
G.o_opt[OPT_O_NOEXEC] = state;
break;
case 'x':
IF_HUSH_MODE_X(G_x_mode = state;)
IF_HUSH_MODE_X(if (G.x_mode_fd <= 0) G.x_mode_fd = dup_CLOEXEC(2, 10);)
break;
case 'o':
if (!o_opt) {
/* "set -+o" without parameter.
* in bash, set -o produces this output:
* pipefail off
* and set +o:
* set +o pipefail
* We always use the second form.
*/
const char *p = o_opt_strings;
idx = 0;
while (*p) {
printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
idx++;
p += strlen(p) + 1;
}
break;
}
idx = index_in_strings(o_opt_strings, o_opt);
if (idx >= 0) {
G.o_opt[idx] = state;
break;
}
case 'e':
G.o_opt[OPT_O_ERREXIT] = state;
break;
default:
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int hush_main(int argc, char **argv)
{
enum {
OPT_login = (1 << 0),
OPT_s = (1 << 1),
};
unsigned flags;
unsigned builtin_argc;
char **e;
struct variable *cur_var;
struct variable *shell_ver;
INIT_G();
if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
G.last_exitcode = EXIT_SUCCESS;
#if ENABLE_HUSH_FAST
G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
#endif
#if !BB_MMU
G.argv0_for_re_execing = argv[0];
#endif
/* Deal with HUSH_VERSION */
debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
shell_ver = xzalloc(sizeof(*shell_ver));
shell_ver->flg_export = 1;
shell_ver->flg_read_only = 1;
/* Code which handles ${var<op>...} needs writable values for all variables,
* therefore we xstrdup: */
shell_ver->varstr = xstrdup(hush_version_str);
/* Create shell local variables from the values
* currently living in the environment */
G.top_var = shell_ver;
cur_var = G.top_var;
e = environ;
if (e) while (*e) {
char *value = strchr(*e, '=');
if (value) { /* paranoia */
cur_var->next = xzalloc(sizeof(*cur_var));
cur_var = cur_var->next;
cur_var->varstr = *e;
cur_var->max_len = strlen(*e);
cur_var->flg_export = 1;
}
e++;
}
/* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
debug_printf_env("putenv '%s'\n", shell_ver->varstr);
putenv(shell_ver->varstr);
/* Export PWD */
set_pwd_var(SETFLAG_EXPORT);
#if ENABLE_HUSH_INTERACTIVE && ENABLE_FEATURE_EDITING_FANCY_PROMPT
/* Set (but not export) PS1/2 unless already set */
if (!get_local_var_value("PS1"))
set_local_var_from_halves("PS1", "\\w \\$ ");
if (!get_local_var_value("PS2"))
set_local_var_from_halves("PS2", "> ");
#endif
#if BASH_HOSTNAME_VAR
/* Set (but not export) HOSTNAME unless already set */
if (!get_local_var_value("HOSTNAME")) {
struct utsname uts;
uname(&uts);
set_local_var_from_halves("HOSTNAME", uts.nodename);
}
#endif
/* IFS is not inherited from the parent environment */
set_local_var_from_halves("IFS", defifs);
/* bash also exports SHLVL and _,
* and sets (but doesn't export) the following variables:
* BASH=/bin/bash
* BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
* BASH_VERSION='3.2.0(1)-release'
* HOSTTYPE=i386
* MACHTYPE=i386-pc-linux-gnu
* OSTYPE=linux-gnu
* PPID=<NNNNN> - we also do it elsewhere
* EUID=<NNNNN>
* UID=<NNNNN>
* GROUPS=()
* LINES=<NNN>
* COLUMNS=<NNN>
* BASH_ARGC=()
* BASH_ARGV=()
* BASH_LINENO=()
* BASH_SOURCE=()
* DIRSTACK=()
* PIPESTATUS=([0]="0")
* HISTFILE=/<xxx>/.bash_history
* HISTFILESIZE=500
* HISTSIZE=500
* MAILCHECK=60
* PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
* SHELL=/bin/bash
* SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
* TERM=dumb
* OPTERR=1
* OPTIND=1
* PS4='+ '
*/
#if ENABLE_HUSH_LINENO_VAR
if (ENABLE_HUSH_LINENO_VAR) {
char *p = xasprintf("LINENO=%*s", (int)(sizeof(int)*3), "");
set_local_var(p, /*flags*/ 0);
G.lineno_var = p; /* can't assign before set_local_var("LINENO=...") */
}
#endif
#if ENABLE_FEATURE_EDITING
G.line_input_state = new_line_input_t(FOR_SHELL);
#endif
/* Initialize some more globals to non-zero values */
cmdedit_update_prompt();
die_func = restore_ttypgrp_and__exit;
/* Shell is non-interactive at first. We need to call
* install_special_sighandlers() if we are going to execute "sh <script>",
* "sh -c <cmds>" or login shell's /etc/profile and friends.
* If we later decide that we are interactive, we run install_special_sighandlers()
* in order to intercept (more) signals.
*/
/* Parse options */
/* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
builtin_argc = 0;
#if NUM_SCRIPTS > 0
if (argc < 0) {
optarg = get_script_content(-argc - 1);
optind = 0;
argc = string_array_len(argv);
goto run_script;
}
#endif
while (1) {
int opt = getopt(argc, argv, "+c:exinsl"
#if !BB_MMU
"<:$:R:V:"
# if ENABLE_HUSH_FUNCTIONS
"F:"
# endif
#endif
);
if (opt <= 0)
break;
switch (opt) {
case 'c':
/* Possibilities:
* sh ... -c 'script'
* sh ... -c 'script' ARG0 [ARG1...]
* On NOMMU, if builtin_argc != 0,
* sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
* "" needs to be replaced with NULL
* and BARGV vector fed to builtin function.
* Note: the form without ARG0 never happens:
* sh ... -c 'builtin' BARGV... ""
*/
#if NUM_SCRIPTS > 0
run_script:
#endif
if (!G.root_pid) {
G.root_pid = getpid();
G.root_ppid = getppid();
}
G.global_argv = argv + optind;
G.global_argc = argc - optind;
if (builtin_argc) {
/* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
const struct built_in_command *x;
install_special_sighandlers();
x = find_builtin(optarg);
if (x) { /* paranoia */
G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
G.global_argv += builtin_argc;
G.global_argv[-1] = NULL; /* replace "" */
fflush_all();
G.last_exitcode = x->b_function(argv + optind - 1);
}
goto final_return;
}
if (!G.global_argv[0]) {
/* -c 'script' (no params): prevent empty $0 */
G.global_argv--; /* points to argv[i] of 'script' */
G.global_argv[0] = argv[0];
G.global_argc++;
} /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
install_special_sighandlers();
parse_and_run_string(optarg);
goto final_return;
case 'i':
/* Well, we cannot just declare interactiveness,
* we have to have some stuff (ctty, etc) */
/* G_interactive_fd++; */
break;
case 's':
flags |= OPT_s;
break;
case 'l':
flags |= OPT_login;
break;
#if !BB_MMU
case '<': /* "big heredoc" support */
full_write1_str(optarg);
_exit(0);
case '$': {
unsigned long long empty_trap_mask;
G.root_pid = bb_strtou(optarg, &optarg, 16);
optarg++;
G.root_ppid = bb_strtou(optarg, &optarg, 16);
optarg++;
G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
optarg++;
G.last_exitcode = bb_strtou(optarg, &optarg, 16);
optarg++;
builtin_argc = bb_strtou(optarg, &optarg, 16);
optarg++;
empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
if (empty_trap_mask != 0) {
IF_HUSH_TRAP(int sig;)
install_special_sighandlers();
# if ENABLE_HUSH_TRAP
G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
for (sig = 1; sig < NSIG; sig++) {
if (empty_trap_mask & (1LL << sig)) {
G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
install_sighandler(sig, SIG_IGN);
}
}
# endif
}
# if ENABLE_HUSH_LOOPS
optarg++;
G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
# endif
# if ENABLE_HUSH_FUNCTIONS
/* nommu uses re-exec trick for "... | func | ...",
* should allow "return".
* This accidentally allows returns in subshells.
*/
G_flag_return_in_progress = -1;
# endif
break;
}
case 'R':
case 'V':
set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
break;
# if ENABLE_HUSH_FUNCTIONS
case 'F': {
struct function *funcp = new_function(optarg);
/* funcp->name is already set to optarg */
/* funcp->body is set to NULL. It's a special case. */
funcp->body_as_string = argv[optind];
optind++;
break;
}
# endif
#endif
case 'n':
case 'x':
case 'e':
if (set_mode(1, opt, NULL) == 0) /* no error */
break;
default:
#ifndef BB_VER
fprintf(stderr, "Usage: sh [FILE]...\n"
" or: sh -c command [args]...\n\n");
exit(EXIT_FAILURE);
#else
bb_show_usage();
#endif
}
} /* option parsing loop */
/* Skip options. Try "hush -l": $1 should not be "-l"! */
G.global_argc = argc - (optind - 1);
G.global_argv = argv + (optind - 1);
G.global_argv[0] = argv[0];
if (!G.root_pid) {
G.root_pid = getpid();
G.root_ppid = getppid();
}
/* If we are login shell... */
if (flags & OPT_login) {
HFILE *input;
debug_printf("sourcing /etc/profile\n");
input = hfopen("/etc/profile");
if (input != NULL) {
install_special_sighandlers();
parse_and_run_file(input);
hfclose(input);
}
/* bash: after sourcing /etc/profile,
* tries to source (in the given order):
* ~/.bash_profile, ~/.bash_login, ~/.profile,
* stopping on first found. --noprofile turns this off.
* bash also sources ~/.bash_logout on exit.
* If called as sh, skips .bash_XXX files.
*/
}
/* -s is: hush -s ARGV1 ARGV2 (no SCRIPT) */
if (!(flags & OPT_s) && G.global_argv[1]) {
HFILE *input;
/*
* "bash <script>" (which is never interactive (unless -i?))
* sources $BASH_ENV here (without scanning $PATH).
* If called as sh, does the same but with $ENV.
* Also NB, per POSIX, $ENV should undergo parameter expansion.
*/
G.global_argc--;
G.global_argv++;
debug_printf("running script '%s'\n", G.global_argv[0]);
xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
input = hfopen(G.global_argv[0]);
if (!input) {
bb_simple_perror_msg_and_die(G.global_argv[0]);
}
xfunc_error_retval = 1;
install_special_sighandlers();
parse_and_run_file(input);
#if ENABLE_FEATURE_CLEAN_UP
hfclose(input);
#endif
goto final_return;
}
/* Up to here, shell was non-interactive. Now it may become one.
* NB: don't forget to (re)run install_special_sighandlers() as needed.
*/
/* A shell is interactive if the '-i' flag was given,
* or if all of the following conditions are met:
* no -c command
* no arguments remaining or the -s flag given
* standard input is a terminal
* standard output is a terminal
* Refer to Posix.2, the description of the 'sh' utility.
*/
#if ENABLE_HUSH_JOB
if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
if (G_saved_tty_pgrp < 0)
G_saved_tty_pgrp = 0;
/* try to dup stdin to high fd#, >= 255 */
G_interactive_fd = dup_CLOEXEC(STDIN_FILENO, 254);
if (G_interactive_fd < 0) {
/* try to dup to any fd */
G_interactive_fd = dup(STDIN_FILENO);
if (G_interactive_fd < 0) {
/* give up */
G_interactive_fd = 0;
G_saved_tty_pgrp = 0;
}
}
// TODO: track & disallow any attempts of user
// to (inadvertently) close/redirect G_interactive_fd
}
debug_printf("interactive_fd:%d\n", G_interactive_fd);
if (G_interactive_fd) {
close_on_exec_on(G_interactive_fd);
if (G_saved_tty_pgrp) {
/* If we were run as 'hush &', sleep until we are
* in the foreground (tty pgrp == our pgrp).
* If we get started under a job aware app (like bash),
* make sure we are now in charge so we don't fight over
* who gets the foreground */
while (1) {
pid_t shell_pgrp = getpgrp();
G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
if (G_saved_tty_pgrp == shell_pgrp)
break;
/* send TTIN to ourself (should stop us) */
kill(- shell_pgrp, SIGTTIN);
}
}
/* Install more signal handlers */
install_special_sighandlers();
if (G_saved_tty_pgrp) {
/* Set other signals to restore saved_tty_pgrp */
install_fatal_sighandlers();
/* Put ourselves in our own process group
* (bash, too, does this only if ctty is available) */
bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
/* Grab control of the terminal */
tcsetpgrp(G_interactive_fd, getpid());
}
enable_restore_tty_pgrp_on_exit();
# if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
{
const char *hp = get_local_var_value("HISTFILE");
if (!hp) {
hp = get_local_var_value("HOME");
if (hp)
hp = concat_path_file(hp, ".hush_history");
} else {
hp = xstrdup(hp);
}
if (hp) {
G.line_input_state->hist_file = hp;
//set_local_var(xasprintf("HISTFILE=%s", ...));
}
# if ENABLE_FEATURE_SH_HISTFILESIZE
hp = get_local_var_value("HISTFILESIZE");
G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
# endif
}
# endif
} else {
install_special_sighandlers();
}
#elif ENABLE_HUSH_INTERACTIVE
/* No job control compiled in, only prompt/line editing */
if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
G_interactive_fd = dup_CLOEXEC(STDIN_FILENO, 254);
if (G_interactive_fd < 0) {
/* try to dup to any fd */
G_interactive_fd = dup_CLOEXEC(STDIN_FILENO, -1);
if (G_interactive_fd < 0)
/* give up */
G_interactive_fd = 0;
}
}
if (G_interactive_fd) {
close_on_exec_on(G_interactive_fd);
}
install_special_sighandlers();
#else
/* We have interactiveness code disabled */
install_special_sighandlers();
#endif
/* bash:
* if interactive but not a login shell, sources ~/.bashrc
* (--norc turns this off, --rcfile <file> overrides)
*/
if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
/* note: ash and hush share this string */
printf("\n\n%s %s\n"
IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
"\n",
bb_banner,
"hush - the humble shell"
);
}
parse_and_run_file(hfopen(NULL)); /* stdin */
final_return:
hush_exit(G.last_exitcode);
}
/*
* Built-ins
*/
static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
{
return 0;
}
#if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
{
int argc = string_array_len(argv);
return applet_main_func(argc, argv);
}
#endif
#if ENABLE_HUSH_TEST || BASH_TEST2
static int FAST_FUNC builtin_test(char **argv)
{
return run_applet_main(argv, test_main);
}
#endif
#if ENABLE_HUSH_ECHO
static int FAST_FUNC builtin_echo(char **argv)
{
return run_applet_main(argv, echo_main);
}
#endif
#if ENABLE_HUSH_PRINTF
static int FAST_FUNC builtin_printf(char **argv)
{
return run_applet_main(argv, printf_main);
}
#endif
#if ENABLE_HUSH_HELP
static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
{
const struct built_in_command *x;
printf(
"Built-in commands:\n"
"------------------\n");
for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
if (x->b_descr)
printf("%-10s%s\n", x->b_cmd, x->b_descr);
}
return EXIT_SUCCESS;
}
#endif
#if MAX_HISTORY && ENABLE_FEATURE_EDITING
static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
{
show_history(G.line_input_state);
return EXIT_SUCCESS;
}
#endif
static char **skip_dash_dash(char **argv)
{
argv++;
if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
argv++;
return argv;
}
static int FAST_FUNC builtin_cd(char **argv)
{
const char *newdir;
argv = skip_dash_dash(argv);
newdir = argv[0];
if (newdir == NULL) {
/* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
* bash says "bash: cd: HOME not set" and does nothing
* (exitcode 1)
*/
const char *home = get_local_var_value("HOME");
newdir = home ? home : "/";
}
if (chdir(newdir)) {
/* Mimic bash message exactly */
bb_perror_msg("cd: %s", newdir);
return EXIT_FAILURE;
}
/* Read current dir (get_cwd(1) is inside) and set PWD.
* Note: do not enforce exporting. If PWD was unset or unexported,
* set it again, but do not export. bash does the same.
*/
set_pwd_var(/*flag:*/ 0);
return EXIT_SUCCESS;
}
static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
{
puts(get_cwd(0));
return EXIT_SUCCESS;
}
static int FAST_FUNC builtin_eval(char **argv)
{
argv = skip_dash_dash(argv);
if (!argv[0])
return EXIT_SUCCESS;
IF_HUSH_MODE_X(G.x_mode_depth++;)
//bb_error_msg("%s: ++x_mode_depth=%d", __func__, G.x_mode_depth);
if (!argv[1]) {
/* bash:
* eval "echo Hi; done" ("done" is syntax error):
* "echo Hi" will not execute too.
*/
parse_and_run_string(argv[0]);
} else {
/* "The eval utility shall construct a command by
* concatenating arguments together, separating
* each with a <space> character."
*/
char *str, *p;
unsigned len = 0;
char **pp = argv;
do
len += strlen(*pp) + 1;
while (*++pp);
str = p = xmalloc(len);
pp = argv;
for (;;) {
p = stpcpy(p, *pp);
pp++;
if (!*pp)
break;
*p++ = ' ';
}
parse_and_run_string(str);
free(str);
}
IF_HUSH_MODE_X(G.x_mode_depth--;)
//bb_error_msg("%s: --x_mode_depth=%d", __func__, G.x_mode_depth);
return G.last_exitcode;
}
static int FAST_FUNC builtin_exec(char **argv)
{
argv = skip_dash_dash(argv);
if (argv[0] == NULL)
return EXIT_SUCCESS; /* bash does this */
/* Careful: we can end up here after [v]fork. Do not restore
* tty pgrp then, only top-level shell process does that */
if (G_saved_tty_pgrp && getpid() == G.root_pid)
tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
/* Saved-redirect fds, script fds and G_interactive_fd are still
* open here. However, they are all CLOEXEC, and execv below
* closes them. Try interactive "exec ls -l /proc/self/fd",
* it should show no extra open fds in the "ls" process.
* If we'd try to run builtins/NOEXECs, this would need improving.
*/
//close_saved_fds_and_FILE_fds();
/* TODO: if exec fails, bash does NOT exit! We do.
* We'll need to undo trap cleanup (it's inside execvp_or_die)
* and tcsetpgrp, and this is inherently racy.
*/
execvp_or_die(argv);
}
static int FAST_FUNC builtin_exit(char **argv)
{
debug_printf_exec("%s()\n", __func__);
/* interactive bash:
* # trap "echo EEE" EXIT
* # exit
* exit
* There are stopped jobs.
* (if there are _stopped_ jobs, running ones don't count)
* # exit
* exit
* EEE (then bash exits)
*
* TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
*/
/* note: EXIT trap is run by hush_exit */
argv = skip_dash_dash(argv);
if (argv[0] == NULL)
hush_exit(G.last_exitcode);
/* mimic bash: exit 123abc == exit 255 + error msg */
xfunc_error_retval = 255;
/* bash: exit -2 == exit 254, no error msg */
hush_exit(xatoi(argv[0]) & 0xff);
}
#if ENABLE_HUSH_TYPE
/* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
static int FAST_FUNC builtin_type(char **argv)
{
int ret = EXIT_SUCCESS;
while (*++argv) {
const char *type;
char *path = NULL;
if (0) {} /* make conditional compile easier below */
/*else if (find_alias(*argv))
type = "an alias";*/
#if ENABLE_HUSH_FUNCTIONS
else if (find_function(*argv))
type = "a function";
#endif
else if (find_builtin(*argv))
type = "a shell builtin";
else if ((path = find_in_path(*argv)) != NULL)
type = path;
else {
bb_error_msg("type: %s: not found", *argv);
ret = EXIT_FAILURE;
continue;
}
printf("%s is %s\n", *argv, type);
free(path);
}
return ret;
}
#endif
#if ENABLE_HUSH_READ
/* Interruptibility of read builtin in bash
* (tested on bash-4.2.8 by sending signals (not by ^C)):
*
* Empty trap makes read ignore corresponding signal, for any signal.
*
* SIGINT:
* - terminates non-interactive shell;
* - interrupts read in interactive shell;
* if it has non-empty trap:
* - executes trap and returns to command prompt in interactive shell;
* - executes trap and returns to read in non-interactive shell;
* SIGTERM:
* - is ignored (does not interrupt) read in interactive shell;
* - terminates non-interactive shell;
* if it has non-empty trap:
* - executes trap and returns to read;
* SIGHUP:
* - terminates shell (regardless of interactivity);
* if it has non-empty trap:
* - executes trap and returns to read;
* SIGCHLD from children:
* - does not interrupt read regardless of interactivity:
* try: sleep 1 & read x; echo $x
*/
static int FAST_FUNC builtin_read(char **argv)
{
const char *r;
struct builtin_read_params params;
memset(&params, 0, sizeof(params));
/* "!": do not abort on errors.
* Option string must start with "sr" to match BUILTIN_READ_xxx
*/
params.read_flags = getopt32(argv,
#if BASH_READ_D
"!srn:p:t:u:d:", &params.opt_n, &params.opt_p, &params.opt_t, &params.opt_u, &params.opt_d
#else
"!srn:p:t:u:", &params.opt_n, &params.opt_p, &params.opt_t, &params.opt_u
#endif
);
if ((uint32_t)params.read_flags == (uint32_t)-1)
return EXIT_FAILURE;
argv += optind;
params.argv = argv;
params.setvar = set_local_var_from_halves;
params.ifs = get_local_var_value("IFS"); /* can be NULL */
again:
r = shell_builtin_read(&params);
if ((uintptr_t)r == 1 && errno == EINTR) {
unsigned sig = check_and_run_traps();
if (sig != SIGINT)
goto again;
}
if ((uintptr_t)r > 1) {
bb_error_msg("%s", r);
r = (char*)(uintptr_t)1;
}
return (uintptr_t)r;
}
#endif
#if ENABLE_HUSH_UMASK
static int FAST_FUNC builtin_umask(char **argv)
{
int rc;
mode_t mask;
rc = 1;
mask = umask(0);
argv = skip_dash_dash(argv);
if (argv[0]) {
mode_t old_mask = mask;
/* numeric umasks are taken as-is */
/* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
if (!isdigit(argv[0][0]))
mask ^= 0777;
mask = bb_parse_mode(argv[0], mask);
if (!isdigit(argv[0][0]))
mask ^= 0777;
if ((unsigned)mask > 0777) {
mask = old_mask;
/* bash messages:
* bash: umask: 'q': invalid symbolic mode operator
* bash: umask: 999: octal number out of range
*/
bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
rc = 0;
}
} else {
/* Mimic bash */
printf("%04o\n", (unsigned) mask);
/* fall through and restore mask which we set to 0 */
}
umask(mask);
return !rc; /* rc != 0 - success */
}
#endif
#if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
static void print_escaped(const char *s)
{
if (*s == '\'')
goto squote;
do {
const char *p = strchrnul(s, '\'');
/* print 'xxxx', possibly just '' */
printf("'%.*s'", (int)(p - s), s);
if (*p == '\0')
break;
s = p;
squote:
/* s points to '; print "'''...'''" */
putchar('"');
do putchar('\''); while (*++s == '\'');
putchar('"');
} while (*s);
}
#endif
#if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
static int helper_export_local(char **argv, unsigned flags)
{
do {
char *name = *argv;
const char *name_end = endofname(name);
if (*name_end == '\0') {
struct variable *var, **vpp;
vpp = get_ptr_to_local_var(name, name_end - name);
var = vpp ? *vpp : NULL;
if (flags & SETFLAG_UNEXPORT) {
/* export -n NAME (without =VALUE) */
if (var) {
var->flg_export = 0;
debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
unsetenv(name);
} /* else: export -n NOT_EXISTING_VAR: no-op */
continue;
}
if (flags & SETFLAG_EXPORT) {
/* export NAME (without =VALUE) */
if (var) {
var->flg_export = 1;
debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
putenv(var->varstr);
continue;
}
}
if (flags & SETFLAG_MAKE_RO) {
/* readonly NAME (without =VALUE) */
if (var) {
var->flg_read_only = 1;
continue;
}
}
# if ENABLE_HUSH_LOCAL
/* Is this "local" bltin? */
if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
unsigned lvl = flags >> SETFLAG_VARLVL_SHIFT;
if (var && var->var_nest_level == lvl) {
/* "local x=abc; ...; local x" - ignore second local decl */
continue;
}
}
# endif
/* Exporting non-existing variable.
* bash does not put it in environment,
* but remembers that it is exported,
* and does put it in env when it is set later.
* We just set it to "" and export.
*/
/* Or, it's "local NAME" (without =VALUE).
* bash sets the value to "".
*/
/* Or, it's "readonly NAME" (without =VALUE).
* bash remembers NAME and disallows its creation
* in the future.
*/
name = xasprintf("%s=", name);
} else {
if (*name_end != '=') {
bb_error_msg("'%s': bad variable name", name);
/* do not parse following argv[]s: */
return 1;
}
/* (Un)exporting/making local NAME=VALUE */
name = xstrdup(name);
/* Testcase: export PS1='\w \$ ' */
unbackslash(name);
}
debug_printf_env("%s: set_local_var('%s')\n", __func__, name);
if (set_local_var(name, flags))
return EXIT_FAILURE;
} while (*++argv);
return EXIT_SUCCESS;
}
#endif
#if ENABLE_HUSH_EXPORT
static int FAST_FUNC builtin_export(char **argv)
{
unsigned opt_unexport;
#if ENABLE_HUSH_EXPORT_N
/* "!": do not abort on errors */
opt_unexport = getopt32(argv, "!n");
if (opt_unexport == (uint32_t)-1)
return EXIT_FAILURE;
argv += optind;
#else
opt_unexport = 0;
argv++;
#endif
if (argv[0] == NULL) {
char **e = environ;
if (e) {
while (*e) {
#if 0
puts(*e++);
#else
/* ash emits: export VAR='VAL'
* bash: declare -x VAR="VAL"
* we follow ash example */
const char *s = *e++;
const char *p = strchr(s, '=');
if (!p) /* wtf? take next variable */
continue;
/* export var= */
printf("export %.*s", (int)(p - s) + 1, s);
print_escaped(p + 1);
putchar('\n');
#endif
}
/*fflush_all(); - done after each builtin anyway */
}
return EXIT_SUCCESS;
}
return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
}
#endif
#if ENABLE_HUSH_LOCAL
static int FAST_FUNC builtin_local(char **argv)
{
if (G.func_nest_level == 0) {
bb_error_msg("%s: not in a function", argv[0]);
return EXIT_FAILURE; /* bash compat */
}
argv++;
/* Since all builtins run in a nested variable level,
* need to use level - 1 here. Or else the variable will be removed at once
* after builtin returns.
*/
return helper_export_local(argv, (G.var_nest_level - 1) << SETFLAG_VARLVL_SHIFT);
}
#endif
#if ENABLE_HUSH_READONLY
static int FAST_FUNC builtin_readonly(char **argv)
{
argv++;
if (*argv == NULL) {
/* bash: readonly [-p]: list all readonly VARs
* (-p has no effect in bash)
*/
struct variable *e;
for (e = G.top_var; e; e = e->next) {
if (e->flg_read_only) {
//TODO: quote value: readonly VAR='VAL'
printf("readonly %s\n", e->varstr);
}
}
return EXIT_SUCCESS;
}
return helper_export_local(argv, SETFLAG_MAKE_RO);
}
#endif
#if ENABLE_HUSH_UNSET
/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
static int FAST_FUNC builtin_unset(char **argv)
{
int ret;
unsigned opts;
/* "!": do not abort on errors */
/* "+": stop at 1st non-option */
opts = getopt32(argv, "!+vf");
if (opts == (unsigned)-1)
return EXIT_FAILURE;
if (opts == 3) {
bb_error_msg("unset: -v and -f are exclusive");
return EXIT_FAILURE;
}
argv += optind;
ret = EXIT_SUCCESS;
while (*argv) {
if (!(opts & 2)) { /* not -f */
if (unset_local_var(*argv)) {
/* unset <nonexistent_var> doesn't fail.
* Error is when one tries to unset RO var.
* Message was printed by unset_local_var. */
ret = EXIT_FAILURE;
}
}
# if ENABLE_HUSH_FUNCTIONS
else {
unset_func(*argv);
}
# endif
argv++;
}
return ret;
}
#endif
#if ENABLE_HUSH_SET
/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
* built-in 'set' handler
* SUSv3 says:
* set [-abCefhmnuvx] [-o option] [argument...]
* set [+abCefhmnuvx] [+o option] [argument...]
* set -- [argument...]
* set -o
* set +o
* Implementations shall support the options in both their hyphen and
* plus-sign forms. These options can also be specified as options to sh.
* Examples:
* Write out all variables and their values: set
* Set $1, $2, and $3 and set "$#" to 3: set c a b
* Turn on the -x and -v options: set -xv
* Unset all positional parameters: set --
* Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
* Set the positional parameters to the expansion of x, even if x expands
* with a leading '-' or '+': set -- $x
*
* So far, we only support "set -- [argument...]" and some of the short names.
*/
static int FAST_FUNC builtin_set(char **argv)
{
int n;
char **pp, **g_argv;
char *arg = *++argv;
if (arg == NULL) {
struct variable *e;
for (e = G.top_var; e; e = e->next)
puts(e->varstr);
return EXIT_SUCCESS;
}
do {
if (strcmp(arg, "--") == 0) {
++argv;
goto set_argv;
}
if (arg[0] != '+' && arg[0] != '-')
break;
for (n = 1; arg[n]; ++n) {
if (set_mode((arg[0] == '-'), arg[n], argv[1]))
goto error;
if (arg[n] == 'o' && argv[1])
argv++;
}
} while ((arg = *++argv) != NULL);
/* Now argv[0] is 1st argument */
if (arg == NULL)
return EXIT_SUCCESS;
set_argv:
/* NB: G.global_argv[0] ($0) is never freed/changed */
g_argv = G.global_argv;
if (G.global_args_malloced) {
pp = g_argv;
while (*++pp)
free(*pp);
g_argv[1] = NULL;
} else {
G.global_args_malloced = 1;
pp = xzalloc(sizeof(pp[0]) * 2);
pp[0] = g_argv[0]; /* retain $0 */
g_argv = pp;
}
/* This realloc's G.global_argv */
G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
G.global_argc = 1 + string_array_len(pp + 1);
return EXIT_SUCCESS;
/* Nothing known, so abort */
error:
bb_error_msg("%s: %s: invalid option", "set", arg);
return EXIT_FAILURE;
}
#endif
static int FAST_FUNC builtin_shift(char **argv)
{
int n = 1;
argv = skip_dash_dash(argv);
if (argv[0]) {
n = bb_strtou(argv[0], NULL, 10);
if (errno || n < 0) {
/* shared string with ash.c */
bb_error_msg("Illegal number: %s", argv[0]);
/*
* ash aborts in this case.
* bash prints error message and set $? to 1.
* Interestingly, for "shift 99999" bash does not
* print error message, but does set $? to 1
* (and does no shifting at all).
*/
}
}
if (n >= 0 && n < G.global_argc) {
if (G_global_args_malloced) {
int m = 1;
while (m <= n)
free(G.global_argv[m++]);
}
G.global_argc -= n;
memmove(&G.global_argv[1], &G.global_argv[n+1],
G.global_argc * sizeof(G.global_argv[0]));
return EXIT_SUCCESS;
}
return EXIT_FAILURE;
}
#if ENABLE_HUSH_GETOPTS
static int FAST_FUNC builtin_getopts(char **argv)
{
/* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/getopts.html
TODO:
If a required argument is not found, and getopts is not silent,
a question mark (?) is placed in VAR, OPTARG is unset, and a
diagnostic message is printed. If getopts is silent, then a
colon (:) is placed in VAR and OPTARG is set to the option
character found.
Test that VAR is a valid variable name?
"Whenever the shell is invoked, OPTIND shall be initialized to 1"
*/
char cbuf[2];
const char *cp, *optstring, *var;
int c, n, exitcode, my_opterr;
unsigned count;
optstring = *++argv;
if (!optstring || !(var = *++argv)) {
bb_error_msg("usage: getopts OPTSTRING VAR [ARGS]");
return EXIT_FAILURE;
}
if (argv[1])
argv[0] = G.global_argv[0]; /* for error messages in getopt() */
else
argv = G.global_argv;
cbuf[1] = '\0';
my_opterr = 0;
if (optstring[0] != ':') {
cp = get_local_var_value("OPTERR");
/* 0 if "OPTERR=0", 1 otherwise */
my_opterr = (!cp || NOT_LONE_CHAR(cp, '0'));
}
/* getopts stops on first non-option. Add "+" to force that */
/*if (optstring[0] != '+')*/ {
char *s = alloca(strlen(optstring) + 2);
sprintf(s, "+%s", optstring);
optstring = s;
}
/* Naively, now we should just
* cp = get_local_var_value("OPTIND");
* optind = cp ? atoi(cp) : 0;
* optarg = NULL;
* opterr = my_opterr;
* c = getopt(string_array_len(argv), argv, optstring);
* and be done? Not so fast...
* Unlike normal getopt() usage in C programs, here
* each successive call will (usually) have the same argv[] CONTENTS,
* but not the ADDRESSES. Worse yet, it's possible that between
* invocations of "getopts", there will be calls to shell builtins
* which use getopt() internally. Example:
* while getopts "abc" RES -a -bc -abc de; do
* unset -ff func
* done
* This would not work correctly: getopt() call inside "unset"
* modifies internal libc state which is tracking position in
* multi-option strings ("-abc"). At best, it can skip options
* or return the same option infinitely. With glibc implementation
* of getopt(), it would use outright invalid pointers and return
* garbage even _without_ "unset" mangling internal state.
*
* We resort to resetting getopt() state and calling it N times,
* until we get Nth result (or failure).
* (N == G.getopt_count is reset to 0 whenever OPTIND is [un]set).
*/
GETOPT_RESET();
count = 0;
n = string_array_len(argv);
do {
optarg = NULL;
opterr = (count < G.getopt_count) ? 0 : my_opterr;
c = getopt(n, argv, optstring);
if (c < 0)
break;
count++;
} while (count <= G.getopt_count);
/* Set OPTIND. Prevent resetting of the magic counter! */
set_local_var_from_halves("OPTIND", utoa(optind));
G.getopt_count = count; /* "next time, give me N+1'th result" */
GETOPT_RESET(); /* just in case */
/* Set OPTARG */
/* Always set or unset, never left as-is, even on exit/error:
* "If no option was found, or if the option that was found
* does not have an option-argument, OPTARG shall be unset."
*/
cp = optarg;
if (c == '?') {
/* If ":optstring" and unknown option is seen,
* it is stored to OPTARG.
*/
if (optstring[1] == ':') {
cbuf[0] = optopt;
cp = cbuf;
}
}
if (cp)
set_local_var_from_halves("OPTARG", cp);
else
unset_local_var("OPTARG");
/* Convert -1 to "?" */
exitcode = EXIT_SUCCESS;
if (c < 0) { /* -1: end of options */
exitcode = EXIT_FAILURE;
c = '?';
}
/* Set VAR */
cbuf[0] = c;
set_local_var_from_halves(var, cbuf);
return exitcode;
}
#endif
static int FAST_FUNC builtin_source(char **argv)
{
char *arg_path, *filename;
HFILE *input;
save_arg_t sv;
char *args_need_save;
#if ENABLE_HUSH_FUNCTIONS
smallint sv_flg;
#endif
argv = skip_dash_dash(argv);
filename = argv[0];
if (!filename) {
/* bash says: "bash: .: filename argument required" */
return 2; /* bash compat */
}
arg_path = NULL;
if (!strchr(filename, '/')) {
arg_path = find_in_path(filename);
if (arg_path)
filename = arg_path;
else if (!ENABLE_HUSH_BASH_SOURCE_CURDIR) {
errno = ENOENT;
bb_simple_perror_msg(filename);
return EXIT_FAILURE;
}
}
input = hfopen(filename);
free(arg_path);
if (!input) {
bb_perror_msg("%s", filename);
/* POSIX: non-interactive shell should abort here,
* not merely fail. So far no one complained :)
*/
return EXIT_FAILURE;
}
#if ENABLE_HUSH_FUNCTIONS
sv_flg = G_flag_return_in_progress;
/* "we are inside sourced file, ok to use return" */
G_flag_return_in_progress = -1;
#endif
args_need_save = argv[1]; /* used as a boolean variable */
if (args_need_save)
save_and_replace_G_args(&sv, argv);
/* "false; . ./empty_line; echo Zero:$?" should print 0 */
G.last_exitcode = 0;
parse_and_run_file(input);
hfclose(input);
if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
restore_G_args(&sv, argv);
#if ENABLE_HUSH_FUNCTIONS
G_flag_return_in_progress = sv_flg;
#endif
return G.last_exitcode;
}
#if ENABLE_HUSH_TRAP
static int FAST_FUNC builtin_trap(char **argv)
{
int sig;
char *new_cmd;
if (!G_traps)
G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
argv++;
if (!*argv) {
int i;
/* No args: print all trapped */
for (i = 0; i < NSIG; ++i) {
if (G_traps[i]) {
printf("trap -- ");
print_escaped(G_traps[i]);
/* note: bash adds "SIG", but only if invoked
* as "bash". If called as "sh", or if set -o posix,
* then it prints short signal names.
* We are printing short names: */
printf(" %s\n", get_signame(i));
}
}
/*fflush_all(); - done after each builtin anyway */
return EXIT_SUCCESS;
}
new_cmd = NULL;
/* If first arg is a number: reset all specified signals */
sig = bb_strtou(*argv, NULL, 10);
if (errno == 0) {
int ret;
process_sig_list:
ret = EXIT_SUCCESS;
while (*argv) {
sighandler_t handler;
sig = get_signum(*argv++);
if (sig < 0) {
ret = EXIT_FAILURE;
/* Mimic bash message exactly */
bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
continue;
}
free(G_traps[sig]);
G_traps[sig] = xstrdup(new_cmd);
debug_printf("trap: setting SIG%s (%i) to '%s'\n",
get_signame(sig), sig, G_traps[sig]);
/* There is no signal for 0 (EXIT) */
if (sig == 0)
continue;
if (new_cmd)
handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
else
/* We are removing trap handler */
handler = pick_sighandler(sig);
install_sighandler(sig, handler);
}
return ret;
}
if (!argv[1]) { /* no second arg */
bb_error_msg("trap: invalid arguments");
return EXIT_FAILURE;
}
/* First arg is "-": reset all specified to default */
/* First arg is "--": skip it, the rest is "handler SIGs..." */
/* Everything else: set arg as signal handler
* (includes "" case, which ignores signal) */
if (argv[0][0] == '-') {
if (argv[0][1] == '\0') { /* "-" */
/* new_cmd remains NULL: "reset these sigs" */
goto reset_traps;
}
if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
argv++;
}
/* else: "-something", no special meaning */
}
new_cmd = *argv;
reset_traps:
argv++;
goto process_sig_list;
}
#endif
#if ENABLE_HUSH_JOB
static struct pipe *parse_jobspec(const char *str)
{
struct pipe *pi;
unsigned jobnum;
if (sscanf(str, "%%%u", &jobnum) != 1) {
if (str[0] != '%'
|| (str[1] != '%' && str[1] != '+' && str[1] != '\0')
) {
bb_error_msg("bad argument '%s'", str);
return NULL;
}
/* It is "%%", "%+" or "%" - current job */
jobnum = G.last_jobid;
if (jobnum == 0) {
bb_error_msg("no current job");
return NULL;
}
}
for (pi = G.job_list; pi; pi = pi->next) {
if (pi->jobid == jobnum) {
return pi;
}
}
bb_error_msg("%u: no such job", jobnum);
return NULL;
}
static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
{
struct pipe *job;
const char *status_string;
checkjobs(NULL, 0 /*(no pid to wait for)*/);
for (job = G.job_list; job; job = job->next) {
if (job->alive_cmds == job->stopped_cmds)
status_string = "Stopped";
else
status_string = "Running";
printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
}
clean_up_last_dead_job();
return EXIT_SUCCESS;
}
/* built-in 'fg' and 'bg' handler */
static int FAST_FUNC builtin_fg_bg(char **argv)
{
int i;
struct pipe *pi;
if (!G_interactive_fd)
return EXIT_FAILURE;
/* If they gave us no args, assume they want the last backgrounded task */
if (!argv[1]) {
for (pi = G.job_list; pi; pi = pi->next) {
if (pi->jobid == G.last_jobid) {
goto found;
}
}
bb_error_msg("%s: no current job", argv[0]);
return EXIT_FAILURE;
}
pi = parse_jobspec(argv[1]);
if (!pi)
return EXIT_FAILURE;
found:
/* TODO: bash prints a string representation
* of job being foregrounded (like "sleep 1 | cat") */
if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
/* Put the job into the foreground. */
tcsetpgrp(G_interactive_fd, pi->pgrp);
}
/* Restart the processes in the job */
debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
for (i = 0; i < pi->num_cmds; i++) {
debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
}
pi->stopped_cmds = 0;
i = kill(- pi->pgrp, SIGCONT);
if (i < 0) {
if (errno == ESRCH) {
delete_finished_job(pi);
return EXIT_SUCCESS;
}
bb_perror_msg("kill (SIGCONT)");
}
if (argv[0][0] == 'f') {
remove_job_from_table(pi); /* FG job shouldn't be in job table */
return checkjobs_and_fg_shell(pi);
}
return EXIT_SUCCESS;
}
#endif
#if ENABLE_HUSH_KILL
static int FAST_FUNC builtin_kill(char **argv)
{
int ret = 0;
# if ENABLE_HUSH_JOB
if (argv[1] && strcmp(argv[1], "-l") != 0) {
int i = 1;
do {
struct pipe *pi;
char *dst;
int j, n;
if (argv[i][0] != '%')
continue;
/*
* "kill %N" - job kill
* Converting to pgrp / pid kill
*/
pi = parse_jobspec(argv[i]);
if (!pi) {
/* Eat bad jobspec */
j = i;
do {
j++;
argv[j - 1] = argv[j];
} while (argv[j]);
ret = 1;
i--;
continue;
}
/*
* In jobs started under job control, we signal
* entire process group by kill -PGRP_ID.
* This happens, f.e., in interactive shell.
*
* Otherwise, we signal each child via
* kill PID1 PID2 PID3.
* Testcases:
* sh -c 'sleep 1|sleep 1 & kill %1'
* sh -c 'true|sleep 2 & sleep 1; kill %1'
* sh -c 'true|sleep 1 & sleep 2; kill %1'
*/
n = G_interactive_fd ? 1 : pi->num_cmds;
dst = alloca(n * sizeof(int)*4);
argv[i] = dst;
if (G_interactive_fd)
dst += sprintf(dst, " -%u", (int)pi->pgrp);
else for (j = 0; j < n; j++) {
struct command *cmd = &pi->cmds[j];
/* Skip exited members of the job */
if (cmd->pid == 0)
continue;
/*
* kill_main has matching code to expect
* leading space. Needed to not confuse
* negative pids with "kill -SIGNAL_NO" syntax
*/
dst += sprintf(dst, " %u", (int)cmd->pid);
}
*dst = '\0';
} while (argv[++i]);
}
# endif
if (argv[1] || ret == 0) {
ret = run_applet_main(argv, kill_main);
}
/* else: ret = 1, "kill %bad_jobspec" case */
return ret;
}
#endif
#if ENABLE_HUSH_WAIT
/* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
#if !ENABLE_HUSH_JOB
# define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
#endif
static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
{
int ret = 0;
for (;;) {
int sig;
sigset_t oldset;
if (!sigisemptyset(&G.pending_set))
goto check_sig;
/* waitpid is not interruptible by SA_RESTARTed
* signals which we use. Thus, this ugly dance:
*/
/* Make sure possible SIGCHLD is stored in kernel's
* pending signal mask before we call waitpid.
* Or else we may race with SIGCHLD, lose it,
* and get stuck in sigsuspend...
*/
sigfillset(&oldset); /* block all signals, remember old set */
sigprocmask2(SIG_SETMASK, &oldset);
if (!sigisemptyset(&G.pending_set)) {
/* Crap! we raced with some signal! */
goto restore;
}
/*errno = 0; - checkjobs does this */
/* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
debug_printf_exec("checkjobs:%d\n", ret);
#if ENABLE_HUSH_JOB
if (waitfor_pipe) {
int rcode = job_exited_or_stopped(waitfor_pipe);
debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
if (rcode >= 0) {
ret = rcode;
sigprocmask(SIG_SETMASK, &oldset, NULL);
break;
}
}
#endif
/* if ECHILD, there are no children (ret is -1 or 0) */
/* if ret == 0, no children changed state */
/* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
if (errno == ECHILD || ret) {
ret--;
if (ret < 0) /* if ECHILD, may need to fix "ret" */
ret = 0;
#if ENABLE_HUSH_BASH_COMPAT
if (waitfor_pid == -1 && errno == ECHILD) {
/* exitcode of "wait -n" with no children is 127, not 0 */
ret = 127;
}
#endif
sigprocmask(SIG_SETMASK, &oldset, NULL);
break;
}
/* Wait for SIGCHLD or any other signal */
/* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
/* Note: sigsuspend invokes signal handler */
sigsuspend(&oldset);
restore:
sigprocmask(SIG_SETMASK, &oldset, NULL);
check_sig:
/* So, did we get a signal? */
sig = check_and_run_traps();
if (sig /*&& sig != SIGCHLD - always true */) {
/* Do this for any (non-ignored) signal, not only for ^C */
ret = 128 + sig;
break;
}
/* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
}
return ret;
}
static int FAST_FUNC builtin_wait(char **argv)
{
int ret;
int status;
argv = skip_dash_dash(argv);
#if ENABLE_HUSH_BASH_COMPAT
if (argv[0] && strcmp(argv[0], "-n") == 0) {
/* wait -n */
/* (bash accepts "wait -n PID" too and ignores PID) */
G.dead_job_exitcode = -1;
return wait_for_child_or_signal(NULL, -1 /*no job, wait for one job*/);
}
#endif
if (argv[0] == NULL) {
/* Don't care about wait results */
/* Note 1: must wait until there are no more children */
/* Note 2: must be interruptible */
/* Examples:
* $ sleep 3 & sleep 6 & wait
* [1] 30934 sleep 3
* [2] 30935 sleep 6
* [1] Done sleep 3
* [2] Done sleep 6
* $ sleep 3 & sleep 6 & wait
* [1] 30936 sleep 3
* [2] 30937 sleep 6
* [1] Done sleep 3
* ^C <-- after ~4 sec from keyboard
* $
*/
return wait_for_child_or_signal(NULL, 0 /*no job and no pid to wait for*/);
}
do {
pid_t pid = bb_strtou(*argv, NULL, 10);
if (errno || pid <= 0) {
#if ENABLE_HUSH_JOB
if (argv[0][0] == '%') {
struct pipe *wait_pipe;
ret = 127; /* bash compat for bad jobspecs */
wait_pipe = parse_jobspec(*argv);
if (wait_pipe) {
ret = job_exited_or_stopped(wait_pipe);
if (ret < 0) {
ret = wait_for_child_or_signal(wait_pipe, 0);
} else {
/* waiting on "last dead job" removes it */
clean_up_last_dead_job();
}
}
/* else: parse_jobspec() already emitted error msg */
continue;
}
#endif
/* mimic bash message */
bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
ret = EXIT_FAILURE;
continue; /* bash checks all argv[] */
}
/* Do we have such child? */
ret = waitpid(pid, &status, WNOHANG);
if (ret < 0) {
/* No */
ret = 127;
if (errno == ECHILD) {
if (pid == G.last_bg_pid) {
/* "wait $!" but last bg task has already exited. Try:
* (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
* In bash it prints exitcode 0, then 3.
* In dash, it is 127.
*/
ret = G.last_bg_pid_exitcode;
} else {
/* Example: "wait 1". mimic bash message */
bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
}
} else {
/* ??? */
bb_perror_msg("wait %s", *argv);
}
continue; /* bash checks all argv[] */
}
if (ret == 0) {
/* Yes, and it still runs */
ret = wait_for_child_or_signal(NULL, pid);
} else {
/* Yes, and it just exited */
process_wait_result(NULL, pid, status);
ret = WEXITSTATUS(status);
if (WIFSIGNALED(status))
ret = 128 + WTERMSIG(status);
}
} while (*++argv);
return ret;
}
#endif
#if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
{
if (argv[1]) {
def = bb_strtou(argv[1], NULL, 10);
if (errno || def < def_min || argv[2]) {
bb_error_msg("%s: bad arguments", argv[0]);
def = UINT_MAX;
}
}
return def;
}
#endif
#if ENABLE_HUSH_LOOPS
static int FAST_FUNC builtin_break(char **argv)
{
unsigned depth;
if (G.depth_of_loop == 0) {
bb_error_msg("%s: only meaningful in a loop", argv[0]);
/* if we came from builtin_continue(), need to undo "= 1" */
G.flag_break_continue = 0;
return EXIT_SUCCESS; /* bash compat */
}
G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
if (depth == UINT_MAX)
G.flag_break_continue = BC_BREAK;
if (G.depth_of_loop < depth)
G.depth_break_continue = G.depth_of_loop;
return EXIT_SUCCESS;
}
static int FAST_FUNC builtin_continue(char **argv)
{
G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
return builtin_break(argv);
}
#endif
#if ENABLE_HUSH_FUNCTIONS
static int FAST_FUNC builtin_return(char **argv)
{
int rc;
if (G_flag_return_in_progress != -1) {
bb_error_msg("%s: not in a function or sourced script", argv[0]);
return EXIT_FAILURE; /* bash compat */
}
G_flag_return_in_progress = 1;
/* bash:
* out of range: wraps around at 256, does not error out
* non-numeric param:
* f() { false; return qwe; }; f; echo $?
* bash: return: qwe: numeric argument required <== we do this
* 255 <== we also do this
*/
rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
return rc;
}
#endif
#if ENABLE_HUSH_TIMES
static int FAST_FUNC builtin_times(char **argv UNUSED_PARAM)
{
static const uint8_t times_tbl[] ALIGN1 = {
' ', offsetof(struct tms, tms_utime),
'\n', offsetof(struct tms, tms_stime),
' ', offsetof(struct tms, tms_cutime),
'\n', offsetof(struct tms, tms_cstime),
0
};
const uint8_t *p;
unsigned clk_tck;
struct tms buf;
clk_tck = bb_clk_tck();
times(&buf);
p = times_tbl;
do {
unsigned sec, frac;
unsigned long t;
t = *(clock_t *)(((char *) &buf) + p[1]);
sec = t / clk_tck;
frac = t % clk_tck;
printf("%um%u.%03us%c",
sec / 60, sec % 60,
(frac * 1000) / clk_tck,
p[0]);
p += 2;
} while (*p);
return EXIT_SUCCESS;
}
#endif
#if ENABLE_HUSH_MEMLEAK
static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
{
void *p;
unsigned long l;
# ifdef M_TRIM_THRESHOLD
/* Optional. Reduces probability of false positives */
malloc_trim(0);
# endif
/* Crude attempt to find where "free memory" starts,
* sans fragmentation. */
p = malloc(240);
l = (unsigned long)p;
free(p);
p = malloc(3400);
if (l < (unsigned long)p) l = (unsigned long)p;
free(p);
# if 0 /* debug */
{
struct mallinfo mi = mallinfo();
printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
}
# endif
if (!G.memleak_value)
G.memleak_value = l;
l -= G.memleak_value;
if ((long)l < 0)
l = 0;
l /= 1024;
if (l > 127)
l = 127;
/* Exitcode is "how many kilobytes we leaked since 1st call" */
return l;
}
#endif
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