/* vi: set sw=4 ts=4: */ /* * ash shell port for busybox * * This code is derived from software contributed to Berkeley by * Kenneth Almquist. * * Original BSD copyright notice is retained at the end of this file. * * Copyright (c) 1989, 1991, 1993, 1994 * The Regents of the University of California. All rights reserved. * * Copyright (c) 1997-2005 Herbert Xu * was re-ported from NetBSD and debianized. * * Licensed under GPLv2 or later, see file LICENSE in this source tree. */ //config:config ASH //config: bool "ash" //config: default y //config: depends on !NOMMU //config: help //config: Tha 'ash' shell adds about 60k in the default configuration and is //config: the most complete and most pedantically correct shell included with //config: busybox. This shell is actually a derivative of the Debian 'dash' //config: shell (by Herbert Xu), which was created by porting the 'ash' shell //config: (written by Kenneth Almquist) from NetBSD. //config: //config:# ash options //config:# note: Don't remove !NOMMU part in the next line; it would break //config:# menuconfig's indenting. //config:if !NOMMU && (ASH || SH_IS_ASH || BASH_IS_ASH) //config: //config:config ASH_OPTIMIZE_FOR_SIZE //config: bool "Optimize for size instead of speed" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: //config:config ASH_INTERNAL_GLOB //config: bool "Use internal glob() implementation" //config: default y # Y is bigger, but because of uclibc glob() bug, let Y be default for now //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: help //config: Do not use glob() function from libc, use internal implementation. //config: Use this if you are getting "glob.h: No such file or directory" //config: or similar build errors. //config: Note that as of now (2017-01), uclibc and musl glob() both have bugs //config: which would break ash if you select N here. //config: //config:config ASH_BASH_COMPAT //config: bool "bash-compatible extensions" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: //config:config ASH_JOB_CONTROL //config: bool "Job control" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: //config:config ASH_ALIAS //config: bool "Alias support" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: //config:config ASH_RANDOM_SUPPORT //config: bool "Pseudorandom generator and $RANDOM variable" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: help //config: Enable pseudorandom generator and dynamic variable "$RANDOM". //config: Each read of "$RANDOM" will generate a new pseudorandom value. //config: You can reset the generator by using a specified start value. //config: After "unset RANDOM" the generator will switch off and this //config: variable will no longer have special treatment. //config: //config:config ASH_EXPAND_PRMT //config: bool "Expand prompt string" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: help //config: $PS# may contain volatile content, such as backquote commands. //config: This option recreates the prompt string from the environment //config: variable each time it is displayed. //config: //config:config ASH_IDLE_TIMEOUT //config: bool "Idle timeout variable $TMOUT" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: help //config: Enable bash-like auto-logout after $TMOUT seconds of idle time. //config: //config:config ASH_MAIL //config: bool "Check for new mail in interactive shell" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: help //config: Enable "check for new mail" function: //config: if set, $MAIL file and $MAILPATH list of files //config: are checked for mtime changes, and "you have mail" //config: message is printed if change is detected. //config: //config:config ASH_ECHO //config: bool "echo builtin" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: //config:config ASH_PRINTF //config: bool "printf builtin" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: //config:config ASH_TEST //config: bool "test builtin" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: //config:config ASH_HELP //config: bool "help builtin" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: //config:config ASH_GETOPTS //config: bool "getopts builtin" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: //config:config ASH_CMDCMD //config: bool "command builtin" //config: default y //config: depends on ASH || SH_IS_ASH || BASH_IS_ASH //config: help //config: Enable support for the 'command' builtin, which allows //config: you to run the specified command or builtin, //config: even when there is a function with the same name. //config: //config:endif # ash options //applet:IF_ASH(APPLET(ash, BB_DIR_BIN, BB_SUID_DROP)) // APPLET_ODDNAME:name main location suid_type help //applet:IF_SH_IS_ASH( APPLET_ODDNAME(sh, ash, BB_DIR_BIN, BB_SUID_DROP, ash)) //applet:IF_BASH_IS_ASH(APPLET_ODDNAME(bash, ash, BB_DIR_BIN, BB_SUID_DROP, ash)) //kbuild:lib-$(CONFIG_ASH) += ash.o ash_ptr_hack.o shell_common.o //kbuild:lib-$(CONFIG_SH_IS_ASH) += ash.o ash_ptr_hack.o shell_common.o //kbuild:lib-$(CONFIG_BASH_IS_ASH) += ash.o ash_ptr_hack.o shell_common.o //kbuild:lib-$(CONFIG_ASH_RANDOM_SUPPORT) += random.o /* * DEBUG=1 to compile in debugging ('set -o debug' turns on) * DEBUG=2 to compile in and turn on debugging. * When debugging is on ("set -o debug" was executed, or DEBUG=2), * debugging info is written to ./trace, quit signal generates core dump. */ #define DEBUG 0 /* Tweak debug output verbosity here */ #define DEBUG_TIME 0 #define DEBUG_PID 1 #define DEBUG_SIG 1 #define DEBUG_INTONOFF 0 #define PROFILE 0 #define JOBS ENABLE_ASH_JOB_CONTROL #include #include #include #include /* for setting $HOSTNAME */ #include "busybox.h" /* for applet_names */ /* So far, all bash compat is controlled by one config option */ /* Separate defines document which part of code implements what */ /* function keyword */ #define BASH_FUNCTION ENABLE_ASH_BASH_COMPAT #define IF_BASH_FUNCTION IF_ASH_BASH_COMPAT /* &>file */ #define BASH_REDIR_OUTPUT ENABLE_ASH_BASH_COMPAT #define IF_BASH_REDIR_OUTPUT IF_ASH_BASH_COMPAT /* $'...' */ #define BASH_DOLLAR_SQUOTE ENABLE_ASH_BASH_COMPAT #define IF_BASH_DOLLAR_SQUOTE IF_ASH_BASH_COMPAT #define BASH_PATTERN_SUBST ENABLE_ASH_BASH_COMPAT #define IF_BASH_PATTERN_SUBST IF_ASH_BASH_COMPAT #define BASH_SUBSTR ENABLE_ASH_BASH_COMPAT #define IF_BASH_SUBSTR IF_ASH_BASH_COMPAT /* [[ EXPR ]] */ #define BASH_TEST2 (ENABLE_ASH_BASH_COMPAT * ENABLE_ASH_TEST) #define BASH_SOURCE ENABLE_ASH_BASH_COMPAT #define BASH_PIPEFAIL ENABLE_ASH_BASH_COMPAT #define BASH_HOSTNAME_VAR ENABLE_ASH_BASH_COMPAT #define BASH_SHLVL_VAR ENABLE_ASH_BASH_COMPAT #if defined(__ANDROID_API__) && __ANDROID_API__ <= 24 /* Bionic at least up to version 24 has no glob() */ # undef ENABLE_ASH_INTERNAL_GLOB # define ENABLE_ASH_INTERNAL_GLOB 1 #endif #if !ENABLE_ASH_INTERNAL_GLOB && defined(__UCLIBC__) # error uClibc glob() is buggy, use ASH_INTERNAL_GLOB. # error The bug is: for "$PWD"/ ash will escape e.g. dashes in "$PWD" # error with backslash, even ones which do not need to be: "/a-b" -> "/a\-b" # error glob() should unbackslash them and match. uClibc does not unbackslash, # error fails to match dirname, subsequently not expanding in it. // Testcase: // if (glob("/etc/polkit\\-1", 0, NULL, &pglob)) - this returns 0 on uclibc, no bug // if (glob("/etc/polkit\\-1/*", 0, NULL, &pglob)) printf("uclibc bug!\n"); #endif #if !ENABLE_ASH_INTERNAL_GLOB # include #endif #include "unicode.h" #include "shell_common.h" #if ENABLE_FEATURE_SH_MATH # include "math.h" #endif #if ENABLE_ASH_RANDOM_SUPPORT # include "random.h" #else # define CLEAR_RANDOM_T(rnd) ((void)0) #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 #ifndef PIPE_BUF # define PIPE_BUF 4096 /* amount of buffering in a pipe */ #endif #if !BB_MMU # error "Do not even bother, ash will not run on NOMMU machine" #endif /* ============ Hash table sizes. Configurable. */ #define VTABSIZE 39 #define ATABSIZE 39 #define CMDTABLESIZE 31 /* should be prime */ /* ============ Shell options */ static const char *const optletters_optnames[] = { "e" "errexit", "f" "noglob", "I" "ignoreeof", "i" "interactive", "m" "monitor", "n" "noexec", "s" "stdin", "x" "xtrace", "v" "verbose", "C" "noclobber", "a" "allexport", "b" "notify", "u" "nounset", "\0" "vi" #if BASH_PIPEFAIL ,"\0" "pipefail" #endif #if DEBUG ,"\0" "nolog" ,"\0" "debug" #endif }; #define optletters(n) optletters_optnames[n][0] #define optnames(n) (optletters_optnames[n] + 1) enum { NOPTS = ARRAY_SIZE(optletters_optnames) }; /* ============ Misc data */ #define msg_illnum "Illegal number: %s" /* * We enclose jmp_buf in a structure so that we can declare pointers to * jump locations. The global variable handler contains the location to * jump to when an exception occurs, and the global variable exception_type * contains a code identifying the exception. To implement nested * exception handlers, the user should save the value of handler on entry * to an inner scope, set handler to point to a jmploc structure for the * inner scope, and restore handler on exit from the scope. */ struct jmploc { jmp_buf loc; }; struct globals_misc { uint8_t exitstatus; /* exit status of last command */ uint8_t back_exitstatus;/* exit status of backquoted command */ smallint job_warning; /* user was warned about stopped jobs (can be 2, 1 or 0). */ int rootpid; /* pid of main shell */ /* shell level: 0 for the main shell, 1 for its children, and so on */ int shlvl; #define rootshell (!shlvl) char *minusc; /* argument to -c option */ char *curdir; // = nullstr; /* current working directory */ char *physdir; // = nullstr; /* physical working directory */ char *arg0; /* value of $0 */ struct jmploc *exception_handler; volatile int suppress_int; /* counter */ volatile /*sig_atomic_t*/ smallint pending_int; /* 1 = got SIGINT */ volatile /*sig_atomic_t*/ smallint got_sigchld; /* 1 = got SIGCHLD */ volatile /*sig_atomic_t*/ smallint pending_sig; /* last pending signal */ smallint exception_type; /* kind of exception (0..5) */ /* exceptions */ #define EXINT 0 /* SIGINT received */ #define EXERROR 1 /* a generic error */ #define EXEXIT 4 /* exit the shell */ smallint isloginsh; char nullstr[1]; /* zero length string */ char optlist[NOPTS]; #define eflag optlist[0] #define fflag optlist[1] #define Iflag optlist[2] #define iflag optlist[3] #define mflag optlist[4] #define nflag optlist[5] #define sflag optlist[6] #define xflag optlist[7] #define vflag optlist[8] #define Cflag optlist[9] #define aflag optlist[10] #define bflag optlist[11] #define uflag optlist[12] #define viflag optlist[13] #if BASH_PIPEFAIL # define pipefail optlist[14] #else # define pipefail 0 #endif #if DEBUG # define nolog optlist[14 + BASH_PIPEFAIL] # define debug optlist[15 + BASH_PIPEFAIL] #endif /* trap handler commands */ /* * Sigmode records the current value of the signal handlers for the various * modes. A value of zero means that the current handler is not known. * S_HARD_IGN indicates that the signal was ignored on entry to the shell. */ char sigmode[NSIG - 1]; #define S_DFL 1 /* default signal handling (SIG_DFL) */ #define S_CATCH 2 /* signal is caught */ #define S_IGN 3 /* signal is ignored (SIG_IGN) */ #define S_HARD_IGN 4 /* signal is ignored permanently */ /* indicates specified signal received */ uint8_t gotsig[NSIG - 1]; /* offset by 1: "signal" 0 is meaningless */ uint8_t may_have_traps; /* 0: definitely no traps are set, 1: some traps may be set */ char *trap[NSIG]; char **trap_ptr; /* used only by "trap hack" */ /* Rarely referenced stuff */ #if ENABLE_ASH_RANDOM_SUPPORT random_t random_gen; #endif pid_t backgndpid; /* pid of last background process */ }; extern struct globals_misc *const ash_ptr_to_globals_misc; #define G_misc (*ash_ptr_to_globals_misc) #define exitstatus (G_misc.exitstatus ) #define back_exitstatus (G_misc.back_exitstatus ) #define job_warning (G_misc.job_warning) #define rootpid (G_misc.rootpid ) #define shlvl (G_misc.shlvl ) #define minusc (G_misc.minusc ) #define curdir (G_misc.curdir ) #define physdir (G_misc.physdir ) #define arg0 (G_misc.arg0 ) #define exception_handler (G_misc.exception_handler) #define exception_type (G_misc.exception_type ) #define suppress_int (G_misc.suppress_int ) #define pending_int (G_misc.pending_int ) #define got_sigchld (G_misc.got_sigchld ) #define pending_sig (G_misc.pending_sig ) #define isloginsh (G_misc.isloginsh ) #define nullstr (G_misc.nullstr ) #define optlist (G_misc.optlist ) #define sigmode (G_misc.sigmode ) #define gotsig (G_misc.gotsig ) #define may_have_traps (G_misc.may_have_traps ) #define trap (G_misc.trap ) #define trap_ptr (G_misc.trap_ptr ) #define random_gen (G_misc.random_gen ) #define backgndpid (G_misc.backgndpid ) #define INIT_G_misc() do { \ (*(struct globals_misc**)&ash_ptr_to_globals_misc) = xzalloc(sizeof(G_misc)); \ barrier(); \ curdir = nullstr; \ physdir = nullstr; \ trap_ptr = trap; \ } while (0) /* ============ DEBUG */ #if DEBUG static void trace_printf(const char *fmt, ...); static void trace_vprintf(const char *fmt, va_list va); # define TRACE(param) trace_printf param # define TRACEV(param) trace_vprintf param # define close(fd) do { \ int dfd = (fd); \ if (close(dfd) < 0) \ bb_error_msg("bug on %d: closing %d(0x%x)", \ __LINE__, dfd, dfd); \ } while (0) #else # define TRACE(param) # define TRACEV(param) #endif /* ============ Utility functions */ #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c))) #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c))) static int isdigit_str9(const char *str) { int maxlen = 9 + 1; /* max 9 digits: 999999999 */ while (--maxlen && isdigit(*str)) str++; return (*str == '\0'); } static const char * var_end(const char *var) { while (*var) if (*var++ == '=') break; return var; } /* ============ Interrupts / exceptions */ static void exitshell(void) NORETURN; /* * These macros allow the user to suspend the handling of interrupt signals * over a period of time. This is similar to SIGHOLD or to sigblock, but * much more efficient and portable. (But hacking the kernel is so much * more fun than worrying about efficiency and portability. :-)) */ #if DEBUG_INTONOFF # define INT_OFF do { \ TRACE(("%s:%d INT_OFF(%d)\n", __func__, __LINE__, suppress_int)); \ suppress_int++; \ barrier(); \ } while (0) #else # define INT_OFF do { \ suppress_int++; \ barrier(); \ } while (0) #endif /* * Called to raise an exception. Since C doesn't include exceptions, we * just do a longjmp to the exception handler. The type of exception is * stored in the global variable "exception_type". */ static void raise_exception(int) NORETURN; static void raise_exception(int e) { #if DEBUG if (exception_handler == NULL) abort(); #endif INT_OFF; exception_type = e; longjmp(exception_handler->loc, 1); } #if DEBUG #define raise_exception(e) do { \ TRACE(("raising exception %d on line %d\n", (e), __LINE__)); \ raise_exception(e); \ } while (0) #endif /* * Called when a SIGINT is received. (If the user specifies * that SIGINT is to be trapped or ignored using the trap builtin, then * this routine is not called.) Suppressint is nonzero when interrupts * are held using the INT_OFF macro. (The test for iflag is just * defensive programming.) */ static void raise_interrupt(void) NORETURN; static void raise_interrupt(void) { pending_int = 0; /* Signal is not automatically unmasked after it is raised, * do it ourself - unmask all signals */ sigprocmask_allsigs(SIG_UNBLOCK); /* pending_sig = 0; - now done in signal_handler() */ if (!(rootshell && iflag)) { /* Kill ourself with SIGINT */ signal(SIGINT, SIG_DFL); raise(SIGINT); } /* bash: ^C even on empty command line sets $? */ exitstatus = SIGINT + 128; raise_exception(EXINT); /* NOTREACHED */ } #if DEBUG #define raise_interrupt() do { \ TRACE(("raising interrupt on line %d\n", __LINE__)); \ raise_interrupt(); \ } while (0) #endif static IF_ASH_OPTIMIZE_FOR_SIZE(inline) void int_on(void) { barrier(); if (--suppress_int == 0 && pending_int) { raise_interrupt(); } } #if DEBUG_INTONOFF # define INT_ON do { \ TRACE(("%s:%d INT_ON(%d)\n", __func__, __LINE__, suppress_int-1)); \ int_on(); \ } while (0) #else # define INT_ON int_on() #endif static IF_ASH_OPTIMIZE_FOR_SIZE(inline) void force_int_on(void) { barrier(); suppress_int = 0; if (pending_int) raise_interrupt(); } #define FORCE_INT_ON force_int_on() #define SAVE_INT(v) ((v) = suppress_int) #define RESTORE_INT(v) do { \ barrier(); \ suppress_int = (v); \ if (suppress_int == 0 && pending_int) \ raise_interrupt(); \ } while (0) /* ============ Stdout/stderr output */ static void outstr(const char *p, FILE *file) { INT_OFF; fputs(p, file); INT_ON; } static void flush_stdout_stderr(void) { INT_OFF; fflush_all(); INT_ON; } /* Was called outcslow(c,FILE*), but c was always '\n' */ static void newline_and_flush(FILE *dest) { INT_OFF; putc('\n', dest); fflush(dest); INT_ON; } static int out1fmt(const char *, ...) __attribute__((__format__(__printf__,1,2))); static int out1fmt(const char *fmt, ...) { va_list ap; int r; INT_OFF; va_start(ap, fmt); r = vprintf(fmt, ap); va_end(ap); INT_ON; return r; } static int fmtstr(char *, size_t, const char *, ...) __attribute__((__format__(__printf__,3,4))); static int fmtstr(char *outbuf, size_t length, const char *fmt, ...) { va_list ap; int ret; va_start(ap, fmt); INT_OFF; ret = vsnprintf(outbuf, length, fmt, ap); va_end(ap); INT_ON; return ret; } static void out1str(const char *p) { outstr(p, stdout); } static void out2str(const char *p) { outstr(p, stderr); flush_stdout_stderr(); } /* ============ Parser structures */ /* control characters in argument strings */ #define CTL_FIRST CTLESC #define CTLESC ((unsigned char)'\201') /* escape next character */ #define CTLVAR ((unsigned char)'\202') /* variable defn */ #define CTLENDVAR ((unsigned char)'\203') #define CTLBACKQ ((unsigned char)'\204') #define CTLARI ((unsigned char)'\206') /* arithmetic expression */ #define CTLENDARI ((unsigned char)'\207') #define CTLQUOTEMARK ((unsigned char)'\210') #define CTL_LAST CTLQUOTEMARK /* variable substitution byte (follows CTLVAR) */ #define VSTYPE 0x0f /* type of variable substitution */ #define VSNUL 0x10 /* colon--treat the empty string as unset */ /* values of VSTYPE field */ #define VSNORMAL 0x1 /* normal variable: $var or ${var} */ #define VSMINUS 0x2 /* ${var-text} */ #define VSPLUS 0x3 /* ${var+text} */ #define VSQUESTION 0x4 /* ${var?message} */ #define VSASSIGN 0x5 /* ${var=text} */ #define VSTRIMRIGHT 0x6 /* ${var%pattern} */ #define VSTRIMRIGHTMAX 0x7 /* ${var%%pattern} */ #define VSTRIMLEFT 0x8 /* ${var#pattern} */ #define VSTRIMLEFTMAX 0x9 /* ${var##pattern} */ #define VSLENGTH 0xa /* ${#var} */ #if BASH_SUBSTR #define VSSUBSTR 0xc /* ${var:position:length} */ #endif #if BASH_PATTERN_SUBST #define VSREPLACE 0xd /* ${var/pattern/replacement} */ #define VSREPLACEALL 0xe /* ${var//pattern/replacement} */ #endif static const char dolatstr[] ALIGN1 = { CTLQUOTEMARK, CTLVAR, VSNORMAL, '@', '=', CTLQUOTEMARK, '\0' }; #define DOLATSTRLEN 6 #define NCMD 0 #define NPIPE 1 #define NREDIR 2 #define NBACKGND 3 #define NSUBSHELL 4 #define NAND 5 #define NOR 6 #define NSEMI 7 #define NIF 8 #define NWHILE 9 #define NUNTIL 10 #define NFOR 11 #define NCASE 12 #define NCLIST 13 #define NDEFUN 14 #define NARG 15 #define NTO 16 #if BASH_REDIR_OUTPUT #define NTO2 17 #endif #define NCLOBBER 18 #define NFROM 19 #define NFROMTO 20 #define NAPPEND 21 #define NTOFD 22 #define NFROMFD 23 #define NHERE 24 #define NXHERE 25 #define NNOT 26 #define N_NUMBER 27 union node; struct ncmd { smallint type; /* Nxxxx */ union node *assign; union node *args; union node *redirect; }; struct npipe { smallint type; smallint pipe_backgnd; struct nodelist *cmdlist; }; struct nredir { smallint type; union node *n; union node *redirect; }; struct nbinary { smallint type; union node *ch1; union node *ch2; }; struct nif { smallint type; union node *test; union node *ifpart; union node *elsepart; }; struct nfor { smallint type; union node *args; union node *body; char *var; }; struct ncase { smallint type; union node *expr; union node *cases; }; struct nclist { smallint type; union node *next; union node *pattern; union node *body; }; struct narg { smallint type; union node *next; char *text; struct nodelist *backquote; }; /* nfile and ndup layout must match! * NTOFD (>&fdnum) uses ndup structure, but we may discover mid-flight * that it is actually NTO2 (>&file), and change its type. */ struct nfile { smallint type; union node *next; int fd; int _unused_dupfd; union node *fname; char *expfname; }; struct ndup { smallint type; union node *next; int fd; int dupfd; union node *vname; char *_unused_expfname; }; struct nhere { smallint type; union node *next; int fd; union node *doc; }; struct nnot { smallint type; union node *com; }; union node { smallint type; struct ncmd ncmd; struct npipe npipe; struct nredir nredir; struct nbinary nbinary; struct nif nif; struct nfor nfor; struct ncase ncase; struct nclist nclist; struct narg narg; struct nfile nfile; struct ndup ndup; struct nhere nhere; struct nnot nnot; }; /* * NODE_EOF is returned by parsecmd when it encounters an end of file. * It must be distinct from NULL. */ #define NODE_EOF ((union node *) -1L) struct nodelist { struct nodelist *next; union node *n; }; struct funcnode { int count; union node n; }; /* * Free a parse tree. */ static void freefunc(struct funcnode *f) { if (f && --f->count < 0) free(f); } /* ============ Debugging output */ #if DEBUG static FILE *tracefile; static void trace_printf(const char *fmt, ...) { va_list va; if (debug != 1) return; if (DEBUG_TIME) fprintf(tracefile, "%u ", (int) time(NULL)); if (DEBUG_PID) fprintf(tracefile, "[%u] ", (int) getpid()); if (DEBUG_SIG) fprintf(tracefile, "pending s:%d i:%d(supp:%d) ", pending_sig, pending_int, suppress_int); va_start(va, fmt); vfprintf(tracefile, fmt, va); va_end(va); } static void trace_vprintf(const char *fmt, va_list va) { if (debug != 1) return; vfprintf(tracefile, fmt, va); fprintf(tracefile, "\n"); } static void trace_puts(const char *s) { if (debug != 1) return; fputs(s, tracefile); } static void trace_puts_quoted(char *s) { char *p; char c; if (debug != 1) return; putc('"', tracefile); for (p = s; *p; p++) { switch ((unsigned char)*p) { case '\n': c = 'n'; goto backslash; case '\t': c = 't'; goto backslash; case '\r': c = 'r'; goto backslash; case '\"': c = '\"'; goto backslash; case '\\': c = '\\'; goto backslash; case CTLESC: c = 'e'; goto backslash; case CTLVAR: c = 'v'; goto backslash; case CTLBACKQ: c = 'q'; goto backslash; backslash: putc('\\', tracefile); putc(c, tracefile); break; default: if (*p >= ' ' && *p <= '~') putc(*p, tracefile); else { putc('\\', tracefile); putc((*p >> 6) & 03, tracefile); putc((*p >> 3) & 07, tracefile); putc(*p & 07, tracefile); } break; } } putc('"', tracefile); } static void trace_puts_args(char **ap) { if (debug != 1) return; if (!*ap) return; while (1) { trace_puts_quoted(*ap); if (!*++ap) { putc('\n', tracefile); break; } putc(' ', tracefile); } } static void opentrace(void) { char s[100]; #ifdef O_APPEND int flags; #endif if (debug != 1) { if (tracefile) fflush(tracefile); /* leave open because libedit might be using it */ return; } strcpy(s, "./trace"); if (tracefile) { if (!freopen(s, "a", tracefile)) { fprintf(stderr, "Can't re-open %s\n", s); debug = 0; return; } } else { tracefile = fopen(s, "a"); if (tracefile == NULL) { fprintf(stderr, "Can't open %s\n", s); debug = 0; return; } } #ifdef O_APPEND flags = fcntl(fileno(tracefile), F_GETFL); if (flags >= 0) fcntl(fileno(tracefile), F_SETFL, flags | O_APPEND); #endif setlinebuf(tracefile); fputs("\nTracing started.\n", tracefile); } static void indent(int amount, char *pfx, FILE *fp) { int i; for (i = 0; i < amount; i++) { if (pfx && i == amount - 1) fputs(pfx, fp); putc('\t', fp); } } /* little circular references here... */ static void shtree(union node *n, int ind, char *pfx, FILE *fp); static void sharg(union node *arg, FILE *fp) { char *p; struct nodelist *bqlist; unsigned char subtype; if (arg->type != NARG) { out1fmt("\n", arg->type); abort(); } bqlist = arg->narg.backquote; for (p = arg->narg.text; *p; p++) { switch ((unsigned char)*p) { case CTLESC: p++; putc(*p, fp); break; case CTLVAR: putc('$', fp); putc('{', fp); subtype = *++p; if (subtype == VSLENGTH) putc('#', fp); while (*p != '=') { putc(*p, fp); p++; } if (subtype & VSNUL) putc(':', fp); switch (subtype & VSTYPE) { case VSNORMAL: putc('}', fp); break; case VSMINUS: putc('-', fp); break; case VSPLUS: putc('+', fp); break; case VSQUESTION: putc('?', fp); break; case VSASSIGN: putc('=', fp); break; case VSTRIMLEFT: putc('#', fp); break; case VSTRIMLEFTMAX: putc('#', fp); putc('#', fp); break; case VSTRIMRIGHT: putc('%', fp); break; case VSTRIMRIGHTMAX: putc('%', fp); putc('%', fp); break; case VSLENGTH: break; default: out1fmt("", subtype); } break; case CTLENDVAR: putc('}', fp); break; case CTLBACKQ: putc('$', fp); putc('(', fp); shtree(bqlist->n, -1, NULL, fp); putc(')', fp); break; default: putc(*p, fp); break; } } } static void shcmd(union node *cmd, FILE *fp) { union node *np; int first; const char *s; int dftfd; first = 1; for (np = cmd->ncmd.args; np; np = np->narg.next) { if (!first) putc(' ', fp); sharg(np, fp); first = 0; } for (np = cmd->ncmd.redirect; np; np = np->nfile.next) { if (!first) putc(' ', fp); dftfd = 0; switch (np->nfile.type) { case NTO: s = ">>"+1; dftfd = 1; break; case NCLOBBER: s = ">|"; dftfd = 1; break; case NAPPEND: s = ">>"; dftfd = 1; break; #if BASH_REDIR_OUTPUT case NTO2: #endif case NTOFD: s = ">&"; dftfd = 1; break; case NFROM: s = "<"; break; case NFROMFD: s = "<&"; break; case NFROMTO: s = "<>"; break; default: s = "*error*"; break; } if (np->nfile.fd != dftfd) fprintf(fp, "%d", np->nfile.fd); fputs(s, fp); if (np->nfile.type == NTOFD || np->nfile.type == NFROMFD) { fprintf(fp, "%d", np->ndup.dupfd); } else { sharg(np->nfile.fname, fp); } first = 0; } } static void shtree(union node *n, int ind, char *pfx, FILE *fp) { struct nodelist *lp; const char *s; if (n == NULL) return; indent(ind, pfx, fp); if (n == NODE_EOF) { fputs("", fp); return; } switch (n->type) { case NSEMI: s = "; "; goto binop; case NAND: s = " && "; goto binop; case NOR: s = " || "; binop: shtree(n->nbinary.ch1, ind, NULL, fp); /* if (ind < 0) */ fputs(s, fp); shtree(n->nbinary.ch2, ind, NULL, fp); break; case NCMD: shcmd(n, fp); if (ind >= 0) putc('\n', fp); break; case NPIPE: for (lp = n->npipe.cmdlist; lp; lp = lp->next) { shtree(lp->n, 0, NULL, fp); if (lp->next) fputs(" | ", fp); } if (n->npipe.pipe_backgnd) fputs(" &", fp); if (ind >= 0) putc('\n', fp); break; default: fprintf(fp, "", n->type); if (ind >= 0) putc('\n', fp); break; } } static void showtree(union node *n) { trace_puts("showtree called\n"); shtree(n, 1, NULL, stderr); } #endif /* DEBUG */ /* ============ Parser data */ /* * ash_vmsg() needs parsefile->fd, hence parsefile definition is moved up. */ struct strlist { struct strlist *next; char *text; }; struct alias; struct strpush { struct strpush *prev; /* preceding string on stack */ char *prev_string; int prev_left_in_line; #if ENABLE_ASH_ALIAS struct alias *ap; /* if push was associated with an alias */ #endif char *string; /* remember the string since it may change */ /* Remember last two characters for pungetc. */ int lastc[2]; /* Number of outstanding calls to pungetc. */ int unget; }; struct parsefile { struct parsefile *prev; /* preceding file on stack */ int linno; /* current line */ int pf_fd; /* file descriptor (or -1 if string) */ int left_in_line; /* number of chars left in this line */ int left_in_buffer; /* number of chars left in this buffer past the line */ char *next_to_pgetc; /* next char in buffer */ char *buf; /* input buffer */ struct strpush *strpush; /* for pushing strings at this level */ struct strpush basestrpush; /* so pushing one is fast */ /* Remember last two characters for pungetc. */ int lastc[2]; /* Number of outstanding calls to pungetc. */ int unget; }; static struct parsefile basepf; /* top level input file */ static struct parsefile *g_parsefile = &basepf; /* current input file */ static int startlinno; /* line # where last token started */ static char *commandname; /* currently executing command */ static struct strlist *cmdenviron; /* environment for builtin command */ /* ============ Message printing */ static void ash_vmsg(const char *msg, va_list ap) { fprintf(stderr, "%s: ", arg0); if (commandname) { if (strcmp(arg0, commandname)) fprintf(stderr, "%s: ", commandname); if (!iflag || g_parsefile->pf_fd > 0) fprintf(stderr, "line %d: ", startlinno); } vfprintf(stderr, msg, ap); newline_and_flush(stderr); } /* * Exverror is called to raise the error exception. If the second argument * is not NULL then error prints an error message using printf style * formatting. It then raises the error exception. */ static void ash_vmsg_and_raise(int, const char *, va_list) NORETURN; static void ash_vmsg_and_raise(int cond, const char *msg, va_list ap) { #if DEBUG if (msg) { TRACE(("ash_vmsg_and_raise(%d):", cond)); TRACEV((msg, ap)); } else TRACE(("ash_vmsg_and_raise(%d):NULL\n", cond)); if (msg) #endif ash_vmsg(msg, ap); flush_stdout_stderr(); raise_exception(cond); /* NOTREACHED */ } static void ash_msg_and_raise_error(const char *, ...) NORETURN; static void ash_msg_and_raise_error(const char *msg, ...) { va_list ap; exitstatus = 2; va_start(ap, msg); ash_vmsg_and_raise(EXERROR, msg, ap); /* NOTREACHED */ va_end(ap); } static void raise_error_syntax(const char *) NORETURN; static void raise_error_syntax(const char *msg) { ash_msg_and_raise_error("syntax error: %s", msg); /* NOTREACHED */ } static void ash_msg_and_raise(int, const char *, ...) NORETURN; static void ash_msg_and_raise(int cond, const char *msg, ...) { va_list ap; va_start(ap, msg); ash_vmsg_and_raise(cond, msg, ap); /* NOTREACHED */ va_end(ap); } /* * error/warning routines for external builtins */ static void ash_msg(const char *fmt, ...) { va_list ap; va_start(ap, fmt); ash_vmsg(fmt, ap); va_end(ap); } /* * Return a string describing an error. The returned string may be a * pointer to a static buffer that will be overwritten on the next call. * Action describes the operation that got the error. */ static const char * errmsg(int e, const char *em) { if (e == ENOENT || e == ENOTDIR) { return em; } return strerror(e); } /* ============ Memory allocation */ #if 0 /* I consider these wrappers nearly useless: * ok, they return you to nearest exception handler, but * how much memory do you leak in the process, making * memory starvation worse? */ static void * ckrealloc(void * p, size_t nbytes) { p = realloc(p, nbytes); if (!p) ash_msg_and_raise_error(bb_msg_memory_exhausted); return p; } static void * ckmalloc(size_t nbytes) { return ckrealloc(NULL, nbytes); } static void * ckzalloc(size_t nbytes) { return memset(ckmalloc(nbytes), 0, nbytes); } static char * ckstrdup(const char *s) { char *p = strdup(s); if (!p) ash_msg_and_raise_error(bb_msg_memory_exhausted); return p; } #else /* Using bbox equivalents. They exit if out of memory */ # define ckrealloc xrealloc # define ckmalloc xmalloc # define ckzalloc xzalloc # define ckstrdup xstrdup #endif /* * It appears that grabstackstr() will barf with such alignments * because stalloc() will return a string allocated in a new stackblock. */ #define SHELL_ALIGN(nbytes) (((nbytes) + SHELL_SIZE) & ~SHELL_SIZE) enum { /* Most machines require the value returned from malloc to be aligned * in some way. The following macro will get this right * on many machines. */ SHELL_SIZE = sizeof(union { int i; char *cp; double d; }) - 1, /* Minimum size of a block */ MINSIZE = SHELL_ALIGN(504), }; struct stack_block { struct stack_block *prev; char space[MINSIZE]; }; struct stackmark { struct stack_block *stackp; char *stacknxt; size_t stacknleft; }; struct globals_memstack { struct stack_block *g_stackp; // = &stackbase; char *g_stacknxt; // = stackbase.space; char *sstrend; // = stackbase.space + MINSIZE; size_t g_stacknleft; // = MINSIZE; struct stack_block stackbase; }; extern struct globals_memstack *const ash_ptr_to_globals_memstack; #define G_memstack (*ash_ptr_to_globals_memstack) #define g_stackp (G_memstack.g_stackp ) #define g_stacknxt (G_memstack.g_stacknxt ) #define sstrend (G_memstack.sstrend ) #define g_stacknleft (G_memstack.g_stacknleft) #define stackbase (G_memstack.stackbase ) #define INIT_G_memstack() do { \ (*(struct globals_memstack**)&ash_ptr_to_globals_memstack) = xzalloc(sizeof(G_memstack)); \ barrier(); \ g_stackp = &stackbase; \ g_stacknxt = stackbase.space; \ g_stacknleft = MINSIZE; \ sstrend = stackbase.space + MINSIZE; \ } while (0) #define stackblock() ((void *)g_stacknxt) #define stackblocksize() g_stacknleft /* * Parse trees for commands are allocated in lifo order, so we use a stack * to make this more efficient, and also to avoid all sorts of exception * handling code to handle interrupts in the middle of a parse. * * The size 504 was chosen because the Ultrix malloc handles that size * well. */ static void * stalloc(size_t nbytes) { char *p; size_t aligned; aligned = SHELL_ALIGN(nbytes); if (aligned > g_stacknleft) { size_t len; size_t blocksize; struct stack_block *sp; blocksize = aligned; if (blocksize < MINSIZE) blocksize = MINSIZE; len = sizeof(struct stack_block) - MINSIZE + blocksize; if (len < blocksize) ash_msg_and_raise_error(bb_msg_memory_exhausted); INT_OFF; sp = ckmalloc(len); sp->prev = g_stackp; g_stacknxt = sp->space; g_stacknleft = blocksize; sstrend = g_stacknxt + blocksize; g_stackp = sp; INT_ON; } p = g_stacknxt; g_stacknxt += aligned; g_stacknleft -= aligned; return p; } static void * stzalloc(size_t nbytes) { return memset(stalloc(nbytes), 0, nbytes); } static void stunalloc(void *p) { #if DEBUG if (!p || (g_stacknxt < (char *)p) || ((char *)p < g_stackp->space)) { write(STDERR_FILENO, "stunalloc\n", 10); abort(); } #endif g_stacknleft += g_stacknxt - (char *)p; g_stacknxt = p; } /* * Like strdup but works with the ash stack. */ static char * sstrdup(const char *p) { size_t len = strlen(p) + 1; return memcpy(stalloc(len), p, len); } static inline void grabstackblock(size_t len) { stalloc(len); } static void pushstackmark(struct stackmark *mark, size_t len) { mark->stackp = g_stackp; mark->stacknxt = g_stacknxt; mark->stacknleft = g_stacknleft; grabstackblock(len); } static void setstackmark(struct stackmark *mark) { pushstackmark(mark, g_stacknxt == g_stackp->space && g_stackp != &stackbase); } static void popstackmark(struct stackmark *mark) { struct stack_block *sp; if (!mark->stackp) return; INT_OFF; while (g_stackp != mark->stackp) { sp = g_stackp; g_stackp = sp->prev; free(sp); } g_stacknxt = mark->stacknxt; g_stacknleft = mark->stacknleft; sstrend = mark->stacknxt + mark->stacknleft; INT_ON; } /* * When the parser reads in a string, it wants to stick the string on the * stack and only adjust the stack pointer when it knows how big the * string is. Stackblock (defined in stack.h) returns a pointer to a block * of space on top of the stack and stackblocklen returns the length of * this block. Growstackblock will grow this space by at least one byte, * possibly moving it (like realloc). Grabstackblock actually allocates the * part of the block that has been used. */ static void growstackblock(void) { size_t newlen; newlen = g_stacknleft * 2; if (newlen < g_stacknleft) ash_msg_and_raise_error(bb_msg_memory_exhausted); if (newlen < 128) newlen += 128; if (g_stacknxt == g_stackp->space && g_stackp != &stackbase) { struct stack_block *sp; struct stack_block *prevstackp; size_t grosslen; INT_OFF; sp = g_stackp; prevstackp = sp->prev; grosslen = newlen + sizeof(struct stack_block) - MINSIZE; sp = ckrealloc(sp, grosslen); sp->prev = prevstackp; g_stackp = sp; g_stacknxt = sp->space; g_stacknleft = newlen; sstrend = sp->space + newlen; INT_ON; } else { char *oldspace = g_stacknxt; size_t oldlen = g_stacknleft; char *p = stalloc(newlen); /* free the space we just allocated */ g_stacknxt = memcpy(p, oldspace, oldlen); g_stacknleft += newlen; } } /* * The following routines are somewhat easier to use than the above. * The user declares a variable of type STACKSTR, which may be declared * to be a register. The macro STARTSTACKSTR initializes things. Then * the user uses the macro STPUTC to add characters to the string. In * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is * grown as necessary. When the user is done, she can just leave the * string there and refer to it using stackblock(). Or she can allocate * the space for it using grabstackstr(). If it is necessary to allow * someone else to use the stack temporarily and then continue to grow * the string, the user should use grabstack to allocate the space, and * then call ungrabstr(p) to return to the previous mode of operation. * * USTPUTC is like STPUTC except that it doesn't check for overflow. * CHECKSTACKSPACE can be called before USTPUTC to ensure that there * is space for at least one character. */ static void * growstackstr(void) { size_t len = stackblocksize(); growstackblock(); return (char *)stackblock() + len; } /* * Called from CHECKSTRSPACE. */ static char * makestrspace(size_t newlen, char *p) { size_t len = p - g_stacknxt; size_t size; for (;;) { size_t nleft; size = stackblocksize(); nleft = size - len; if (nleft >= newlen) break; growstackblock(); } return (char *)stackblock() + len; } static char * stack_nputstr(const char *s, size_t n, char *p) { p = makestrspace(n, p); p = (char *)memcpy(p, s, n) + n; return p; } static char * stack_putstr(const char *s, char *p) { return stack_nputstr(s, strlen(s), p); } static char * _STPUTC(int c, char *p) { if (p == sstrend) p = growstackstr(); *p++ = c; return p; } #define STARTSTACKSTR(p) ((p) = stackblock()) #define STPUTC(c, p) ((p) = _STPUTC((c), (p))) #define CHECKSTRSPACE(n, p) do { \ char *q = (p); \ size_t l = (n); \ size_t m = sstrend - q; \ if (l > m) \ (p) = makestrspace(l, q); \ } while (0) #define USTPUTC(c, p) (*(p)++ = (c)) #define STACKSTRNUL(p) do { \ if ((p) == sstrend) \ (p) = growstackstr(); \ *(p) = '\0'; \ } while (0) #define STUNPUTC(p) (--(p)) #define STTOPC(p) ((p)[-1]) #define STADJUST(amount, p) ((p) += (amount)) #define grabstackstr(p) stalloc((char *)(p) - (char *)stackblock()) #define ungrabstackstr(s, p) stunalloc(s) #define stackstrend() ((void *)sstrend) /* ============ String helpers */ /* * prefix -- see if pfx is a prefix of string. */ static char * prefix(const char *string, const char *pfx) { while (*pfx) { if (*pfx++ != *string++) return NULL; } return (char *) string; } /* * Check for a valid number. This should be elsewhere. */ static int is_number(const char *p) { do { if (!isdigit(*p)) return 0; } while (*++p != '\0'); return 1; } /* * Convert a string of digits to an integer, printing an error message on * failure. */ static int number(const char *s) { if (!is_number(s)) ash_msg_and_raise_error(msg_illnum, s); return atoi(s); } /* * Produce a possibly single quoted string suitable as input to the shell. * The return string is allocated on the stack. */ static char * single_quote(const char *s) { char *p; STARTSTACKSTR(p); do { char *q; size_t len; len = strchrnul(s, '\'') - s; q = p = makestrspace(len + 3, p); *q++ = '\''; q = (char *)memcpy(q, s, len) + len; *q++ = '\''; s += len; STADJUST(q - p, p); if (*s != '\'') break; len = 0; do len++; while (*++s == '\''); q = p = makestrspace(len + 3, p); *q++ = '"'; q = (char *)memcpy(q, s - len, len) + len; *q++ = '"'; STADJUST(q - p, p); } while (*s); USTPUTC('\0', p); return stackblock(); } /* ============ nextopt */ static char **argptr; /* argument list for builtin commands */ static char *optionarg; /* set by nextopt (like getopt) */ static char *optptr; /* used by nextopt */ /* * XXX - should get rid of. Have all builtins use getopt(3). * The library getopt must have the BSD extension static variable * "optreset", otherwise it can't be used within the shell safely. * * Standard option processing (a la getopt) for builtin routines. * The only argument that is passed to nextopt is the option string; * the other arguments are unnecessary. It returns the character, * or '\0' on end of input. */ static int nextopt(const char *optstring) { char *p; const char *q; char c; p = optptr; if (p == NULL || *p == '\0') { /* We ate entire "-param", take next one */ p = *argptr; if (p == NULL) return '\0'; if (*p != '-') return '\0'; if (*++p == '\0') /* just "-" ? */ return '\0'; argptr++; if (LONE_DASH(p)) /* "--" ? */ return '\0'; /* p => next "-param" */ } /* p => some option char in the middle of a "-param" */ c = *p++; for (q = optstring; *q != c;) { if (*q == '\0') ash_msg_and_raise_error("illegal option -%c", c); if (*++q == ':') q++; } if (*++q == ':') { if (*p == '\0') { p = *argptr++; if (p == NULL) ash_msg_and_raise_error("no arg for -%c option", c); } optionarg = p; p = NULL; } optptr = p; return c; } /* ============ Shell variables */ /* * The parsefile structure pointed to by the global variable parsefile * contains information about the current file being read. */ struct shparam { int nparam; /* # of positional parameters (without $0) */ #if ENABLE_ASH_GETOPTS int optind; /* next parameter to be processed by getopts */ int optoff; /* used by getopts */ #endif unsigned char malloced; /* if parameter list dynamically allocated */ char **p; /* parameter list */ }; /* * Free the list of positional parameters. */ static void freeparam(volatile struct shparam *param) { if (param->malloced) { char **ap, **ap1; ap = ap1 = param->p; while (*ap) free(*ap++); free(ap1); } } #if ENABLE_ASH_GETOPTS static void FAST_FUNC getoptsreset(const char *value); #endif struct var { struct var *next; /* next entry in hash list */ int flags; /* flags are defined above */ const char *var_text; /* name=value */ void (*var_func)(const char *) FAST_FUNC; /* function to be called when */ /* the variable gets set/unset */ }; struct localvar { struct localvar *next; /* next local variable in list */ struct var *vp; /* the variable that was made local */ int flags; /* saved flags */ const char *text; /* saved text */ }; /* flags */ #define VEXPORT 0x01 /* variable is exported */ #define VREADONLY 0x02 /* variable cannot be modified */ #define VSTRFIXED 0x04 /* variable struct is statically allocated */ #define VTEXTFIXED 0x08 /* text is statically allocated */ #define VSTACK 0x10 /* text is allocated on the stack */ #define VUNSET 0x20 /* the variable is not set */ #define VNOFUNC 0x40 /* don't call the callback function */ #define VNOSET 0x80 /* do not set variable - just readonly test */ #define VNOSAVE 0x100 /* when text is on the heap before setvareq */ #if ENABLE_ASH_RANDOM_SUPPORT # define VDYNAMIC 0x200 /* dynamic variable */ #else # define VDYNAMIC 0 #endif /* Need to be before varinit_data[] */ #if ENABLE_LOCALE_SUPPORT static void FAST_FUNC change_lc_all(const char *value) { if (value && *value != '\0') setlocale(LC_ALL, value); } static void FAST_FUNC change_lc_ctype(const char *value) { if (value && *value != '\0') setlocale(LC_CTYPE, value); } #endif #if ENABLE_ASH_MAIL static void chkmail(void); static void changemail(const char *var_value) FAST_FUNC; #else # define chkmail() ((void)0) #endif static void changepath(const char *) FAST_FUNC; #if ENABLE_ASH_RANDOM_SUPPORT static void change_random(const char *) FAST_FUNC; #endif static const struct { int flags; const char *var_text; void (*var_func)(const char *) FAST_FUNC; } varinit_data[] = { /* * Note: VEXPORT would not work correctly here for NOFORK applets: * some environment strings may be constant. */ { VSTRFIXED|VTEXTFIXED , defifsvar , NULL }, #if ENABLE_ASH_MAIL { VSTRFIXED|VTEXTFIXED|VUNSET, "MAIL" , changemail }, { VSTRFIXED|VTEXTFIXED|VUNSET, "MAILPATH" , changemail }, #endif { VSTRFIXED|VTEXTFIXED , bb_PATH_root_path, changepath }, { VSTRFIXED|VTEXTFIXED , "PS1=$ " , NULL }, { VSTRFIXED|VTEXTFIXED , "PS2=> " , NULL }, { VSTRFIXED|VTEXTFIXED , "PS4=+ " , NULL }, #if ENABLE_ASH_GETOPTS { VSTRFIXED|VTEXTFIXED , defoptindvar, getoptsreset }, #endif #if ENABLE_ASH_RANDOM_SUPPORT { VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "RANDOM", change_random }, #endif #if ENABLE_LOCALE_SUPPORT { VSTRFIXED|VTEXTFIXED|VUNSET, "LC_ALL" , change_lc_all }, { VSTRFIXED|VTEXTFIXED|VUNSET, "LC_CTYPE" , change_lc_ctype }, #endif #if ENABLE_FEATURE_EDITING_SAVEHISTORY { VSTRFIXED|VTEXTFIXED|VUNSET, "HISTFILE" , NULL }, #endif }; struct redirtab; struct globals_var { struct shparam shellparam; /* $@ current positional parameters */ struct redirtab *redirlist; int preverrout_fd; /* save fd2 before print debug if xflag is set. */ struct var *vartab[VTABSIZE]; struct var varinit[ARRAY_SIZE(varinit_data)]; }; extern struct globals_var *const ash_ptr_to_globals_var; #define G_var (*ash_ptr_to_globals_var) #define shellparam (G_var.shellparam ) //#define redirlist (G_var.redirlist ) #define preverrout_fd (G_var.preverrout_fd) #define vartab (G_var.vartab ) #define varinit (G_var.varinit ) #define INIT_G_var() do { \ unsigned i; \ (*(struct globals_var**)&ash_ptr_to_globals_var) = xzalloc(sizeof(G_var)); \ barrier(); \ for (i = 0; i < ARRAY_SIZE(varinit_data); i++) { \ varinit[i].flags = varinit_data[i].flags; \ varinit[i].var_text = varinit_data[i].var_text; \ varinit[i].var_func = varinit_data[i].var_func; \ } \ } while (0) #define vifs varinit[0] #if ENABLE_ASH_MAIL # define vmail (&vifs)[1] # define vmpath (&vmail)[1] # define vpath (&vmpath)[1] #else # define vpath (&vifs)[1] #endif #define vps1 (&vpath)[1] #define vps2 (&vps1)[1] #define vps4 (&vps2)[1] #if ENABLE_ASH_GETOPTS # define voptind (&vps4)[1] # if ENABLE_ASH_RANDOM_SUPPORT # define vrandom (&voptind)[1] # endif #else # if ENABLE_ASH_RANDOM_SUPPORT # define vrandom (&vps4)[1] # endif #endif /* * The following macros access the values of the above variables. * They have to skip over the name. They return the null string * for unset variables. */ #define ifsval() (vifs.var_text + 4) #define ifsset() ((vifs.flags & VUNSET) == 0) #if ENABLE_ASH_MAIL # define mailval() (vmail.var_text + 5) # define mpathval() (vmpath.var_text + 9) # define mpathset() ((vmpath.flags & VUNSET) == 0) #endif #define pathval() (vpath.var_text + 5) #define ps1val() (vps1.var_text + 4) #define ps2val() (vps2.var_text + 4) #define ps4val() (vps4.var_text + 4) #if ENABLE_ASH_GETOPTS # define optindval() (voptind.var_text + 7) #endif #if ENABLE_ASH_GETOPTS static void FAST_FUNC getoptsreset(const char *value) { shellparam.optind = number(value) ?: 1; shellparam.optoff = -1; } #endif /* * Compares two strings up to the first = or '\0'. The first * string must be terminated by '='; the second may be terminated by * either '=' or '\0'. */ static int varcmp(const char *p, const char *q) { int c, d; while ((c = *p) == (d = *q)) { if (c == '\0' || c == '=') goto out; p++; q++; } if (c == '=') c = '\0'; if (d == '=') d = '\0'; out: return c - d; } /* * Find the appropriate entry in the hash table from the name. */ static struct var ** hashvar(const char *p) { unsigned hashval; hashval = ((unsigned char) *p) << 4; while (*p && *p != '=') hashval += (unsigned char) *p++; return &vartab[hashval % VTABSIZE]; } static int vpcmp(const void *a, const void *b) { return varcmp(*(const char **)a, *(const char **)b); } /* * This routine initializes the builtin variables. */ static void initvar(void) { struct var *vp; struct var *end; struct var **vpp; /* * PS1 depends on uid */ #if ENABLE_FEATURE_EDITING && ENABLE_FEATURE_EDITING_FANCY_PROMPT vps1.var_text = "PS1=\\w \\$ "; #else if (!geteuid()) vps1.var_text = "PS1=# "; #endif vp = varinit; end = vp + ARRAY_SIZE(varinit); do { vpp = hashvar(vp->var_text); vp->next = *vpp; *vpp = vp; } while (++vp < end); } static struct var ** findvar(struct var **vpp, const char *name) { for (; *vpp; vpp = &(*vpp)->next) { if (varcmp((*vpp)->var_text, name) == 0) { break; } } return vpp; } /* * Find the value of a variable. Returns NULL if not set. */ static const char* FAST_FUNC lookupvar(const char *name) { struct var *v; v = *findvar(hashvar(name), name); if (v) { #if ENABLE_ASH_RANDOM_SUPPORT /* * Dynamic variables are implemented roughly the same way they are * in bash. Namely, they're "special" so long as they aren't unset. * As soon as they're unset, they're no longer dynamic, and dynamic * lookup will no longer happen at that point. -- PFM. */ if (v->flags & VDYNAMIC) v->var_func(NULL); #endif if (!(v->flags & VUNSET)) return var_end(v->var_text); } return NULL; } #if ENABLE_UNICODE_SUPPORT static void reinit_unicode_for_ash(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 = lookupvar("LC_ALL"); if (!s) s = lookupvar("LC_CTYPE"); if (!s) s = lookupvar("LANG"); reinit_unicode(s); } } #else # define reinit_unicode_for_ash() ((void)0) #endif /* * Search the environment of a builtin command. */ static const char * bltinlookup(const char *name) { struct strlist *sp; for (sp = cmdenviron; sp; sp = sp->next) { if (varcmp(sp->text, name) == 0) return var_end(sp->text); } return lookupvar(name); } /* * Same as setvar except that the variable and value are passed in * the first argument as name=value. Since the first argument will * be actually stored in the table, it should not be a string that * will go away. * Called with interrupts off. */ static void setvareq(char *s, int flags) { struct var *vp, **vpp; vpp = hashvar(s); flags |= (VEXPORT & (((unsigned) (1 - aflag)) - 1)); vp = *findvar(vpp, s); if (vp) { if ((vp->flags & (VREADONLY|VDYNAMIC)) == VREADONLY) { const char *n; if (flags & VNOSAVE) free(s); n = vp->var_text; exitstatus = 1; ash_msg_and_raise_error("%.*s: is read only", strchrnul(n, '=') - n, n); } if (flags & VNOSET) return; if (vp->var_func && !(flags & VNOFUNC)) vp->var_func(var_end(s)); if (!(vp->flags & (VTEXTFIXED|VSTACK))) free((char*)vp->var_text); flags |= vp->flags & ~(VTEXTFIXED|VSTACK|VNOSAVE|VUNSET); } else { /* variable s is not found */ if (flags & VNOSET) return; vp = ckzalloc(sizeof(*vp)); vp->next = *vpp; /*vp->func = NULL; - ckzalloc did it */ *vpp = vp; } if (!(flags & (VTEXTFIXED|VSTACK|VNOSAVE))) s = ckstrdup(s); vp->var_text = s; vp->flags = flags; } /* * Set the value of a variable. The flags argument is ored with the * flags of the variable. If val is NULL, the variable is unset. */ static void setvar(const char *name, const char *val, int flags) { const char *q; char *p; char *nameeq; size_t namelen; size_t vallen; q = endofname(name); p = strchrnul(q, '='); namelen = p - name; if (!namelen || p != q) ash_msg_and_raise_error("%.*s: bad variable name", namelen, name); vallen = 0; if (val == NULL) { flags |= VUNSET; } else { vallen = strlen(val); } INT_OFF; nameeq = ckmalloc(namelen + vallen + 2); p = memcpy(nameeq, name, namelen) + namelen; if (val) { *p++ = '='; p = memcpy(p, val, vallen) + vallen; } *p = '\0'; setvareq(nameeq, flags | VNOSAVE); INT_ON; } static void FAST_FUNC setvar0(const char *name, const char *val) { setvar(name, val, 0); } /* * Unset the specified variable. */ static int unsetvar(const char *s) { struct var **vpp; struct var *vp; int retval; vpp = findvar(hashvar(s), s); vp = *vpp; retval = 2; if (vp) { int flags = vp->flags; retval = 1; if (flags & VREADONLY) goto out; #if ENABLE_ASH_RANDOM_SUPPORT vp->flags &= ~VDYNAMIC; #endif if (flags & VUNSET) goto ok; if ((flags & VSTRFIXED) == 0) { INT_OFF; if ((flags & (VTEXTFIXED|VSTACK)) == 0) free((char*)vp->var_text); *vpp = vp->next; free(vp); INT_ON; } else { setvar0(s, NULL); vp->flags &= ~VEXPORT; } ok: retval = 0; } out: return retval; } /* * Process a linked list of variable assignments. */ static void listsetvar(struct strlist *list_set_var, int flags) { struct strlist *lp = list_set_var; if (!lp) return; INT_OFF; do { setvareq(lp->text, flags); lp = lp->next; } while (lp); INT_ON; } /* * Generate a list of variables satisfying the given conditions. */ static char ** listvars(int on, int off, char ***end) { struct var **vpp; struct var *vp; char **ep; int mask; STARTSTACKSTR(ep); vpp = vartab; mask = on | off; do { for (vp = *vpp; vp; vp = vp->next) { if ((vp->flags & mask) == on) { if (ep == stackstrend()) ep = growstackstr(); *ep++ = (char*)vp->var_text; } } } while (++vpp < vartab + VTABSIZE); if (ep == stackstrend()) ep = growstackstr(); if (end) *end = ep; *ep++ = NULL; return grabstackstr(ep); } /* ============ Path search helper * * The variable path (passed by reference) should be set to the start * of the path before the first call; path_advance will update * this value as it proceeds. Successive calls to path_advance will return * the possible path expansions in sequence. If an option (indicated by * a percent sign) appears in the path entry then the global variable * pathopt will be set to point to it; otherwise pathopt will be set to * NULL. */ static const char *pathopt; /* set by path_advance */ static char * path_advance(const char **path, const char *name) { const char *p; char *q; const char *start; size_t len; if (*path == NULL) return NULL; start = *path; for (p = start; *p && *p != ':' && *p != '%'; p++) continue; len = p - start + strlen(name) + 2; /* "2" is for '/' and '\0' */ while (stackblocksize() < len) growstackblock(); q = stackblock(); if (p != start) { memcpy(q, start, p - start); q += p - start; *q++ = '/'; } strcpy(q, name); pathopt = NULL; if (*p == '%') { pathopt = ++p; while (*p && *p != ':') p++; } if (*p == ':') *path = p + 1; else *path = NULL; return stalloc(len); } /* ============ Prompt */ static smallint doprompt; /* if set, prompt the user */ static smallint needprompt; /* true if interactive and at start of line */ #if ENABLE_FEATURE_EDITING static line_input_t *line_input_state; static const char *cmdedit_prompt; static void putprompt(const char *s) { if (ENABLE_ASH_EXPAND_PRMT) { free((char*)cmdedit_prompt); cmdedit_prompt = ckstrdup(s); return; } cmdedit_prompt = s; } #else static void putprompt(const char *s) { out2str(s); } #endif /* expandstr() needs parsing machinery, so it is far away ahead... */ static const char *expandstr(const char *ps); static void setprompt_if(smallint do_set, int whichprompt) { const char *prompt; IF_ASH_EXPAND_PRMT(struct stackmark smark;) if (!do_set) return; needprompt = 0; switch (whichprompt) { case 1: prompt = ps1val(); break; case 2: prompt = ps2val(); break; default: /* 0 */ prompt = nullstr; } #if ENABLE_ASH_EXPAND_PRMT pushstackmark(&smark, stackblocksize()); putprompt(expandstr(prompt)); popstackmark(&smark); #else putprompt(prompt); #endif } /* ============ The cd and pwd commands */ #define CD_PHYSICAL 1 #define CD_PRINT 2 static int cdopt(void) { int flags = 0; int i, j; j = 'L'; while ((i = nextopt("LP")) != '\0') { if (i != j) { flags ^= CD_PHYSICAL; j = i; } } return flags; } /* * Update curdir (the name of the current directory) in response to a * cd command. */ static const char * updatepwd(const char *dir) { char *new; char *p; char *cdcomppath; const char *lim; cdcomppath = sstrdup(dir); STARTSTACKSTR(new); if (*dir != '/') { if (curdir == nullstr) return 0; new = stack_putstr(curdir, new); } new = makestrspace(strlen(dir) + 2, new); lim = (char *)stackblock() + 1; if (*dir != '/') { if (new[-1] != '/') USTPUTC('/', new); if (new > lim && *lim == '/') lim++; } else { USTPUTC('/', new); cdcomppath++; if (dir[1] == '/' && dir[2] != '/') { USTPUTC('/', new); cdcomppath++; lim++; } } p = strtok(cdcomppath, "/"); while (p) { switch (*p) { case '.': if (p[1] == '.' && p[2] == '\0') { while (new > lim) { STUNPUTC(new); if (new[-1] == '/') break; } break; } if (p[1] == '\0') break; /* fall through */ default: new = stack_putstr(p, new); USTPUTC('/', new); } p = strtok(NULL, "/"); } if (new > lim) STUNPUTC(new); *new = 0; return stackblock(); } /* * Find out what the current directory is. If we already know the current * directory, this routine returns immediately. */ static char * getpwd(void) { char *dir = getcwd(NULL, 0); /* huh, using glibc extension? */ return dir ? dir : nullstr; } static void setpwd(const char *val, int setold) { char *oldcur, *dir; oldcur = dir = curdir; if (setold) { setvar("OLDPWD", oldcur, VEXPORT); } INT_OFF; if (physdir != nullstr) { if (physdir != oldcur) free(physdir); physdir = nullstr; } if (oldcur == val || !val) { char *s = getpwd(); physdir = s; if (!val) dir = s; } else dir = ckstrdup(val); if (oldcur != dir && oldcur != nullstr) { free(oldcur); } curdir = dir; INT_ON; setvar("PWD", dir, VEXPORT); } static void hashcd(void); /* * Actually do the chdir. We also call hashcd to let other routines * know that the current directory has changed. */ static int docd(const char *dest, int flags) { const char *dir = NULL; int err; TRACE(("docd(\"%s\", %d) called\n", dest, flags)); INT_OFF; if (!(flags & CD_PHYSICAL)) { dir = updatepwd(dest); if (dir) dest = dir; } err = chdir(dest); if (err) goto out; setpwd(dir, 1); hashcd(); out: INT_ON; return err; } static int FAST_FUNC cdcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { const char *dest; const char *path; const char *p; char c; struct stat statb; int flags; flags = cdopt(); dest = *argptr; if (!dest) dest = bltinlookup("HOME"); else if (LONE_DASH(dest)) { dest = bltinlookup("OLDPWD"); flags |= CD_PRINT; } if (!dest) dest = nullstr; if (*dest == '/') goto step6; if (*dest == '.') { c = dest[1]; dotdot: switch (c) { case '\0': case '/': goto step6; case '.': c = dest[2]; if (c != '.') goto dotdot; } } if (!*dest) dest = "."; path = bltinlookup("CDPATH"); while (path) { c = *path; p = path_advance(&path, dest); if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) { if (c && c != ':') flags |= CD_PRINT; docd: if (!docd(p, flags)) goto out; goto err; } } step6: p = dest; goto docd; err: ash_msg_and_raise_error("can't cd to %s", dest); /* NOTREACHED */ out: if (flags & CD_PRINT) out1fmt("%s\n", curdir); return 0; } static int FAST_FUNC pwdcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { int flags; const char *dir = curdir; flags = cdopt(); if (flags) { if (physdir == nullstr) setpwd(dir, 0); dir = physdir; } out1fmt("%s\n", dir); return 0; } /* ============ ... */ #define IBUFSIZ (ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 1024) /* Syntax classes */ #define CWORD 0 /* character is nothing special */ #define CNL 1 /* newline character */ #define CBACK 2 /* a backslash character */ #define CSQUOTE 3 /* single quote */ #define CDQUOTE 4 /* double quote */ #define CENDQUOTE 5 /* a terminating quote */ #define CBQUOTE 6 /* backwards single quote */ #define CVAR 7 /* a dollar sign */ #define CENDVAR 8 /* a '}' character */ #define CLP 9 /* a left paren in arithmetic */ #define CRP 10 /* a right paren in arithmetic */ #define CENDFILE 11 /* end of file */ #define CCTL 12 /* like CWORD, except it must be escaped */ #define CSPCL 13 /* these terminate a word */ #define CIGN 14 /* character should be ignored */ #define PEOF 256 #if ENABLE_ASH_ALIAS # define PEOA 257 #endif #define USE_SIT_FUNCTION ENABLE_ASH_OPTIMIZE_FOR_SIZE #if ENABLE_FEATURE_SH_MATH # define SIT_ITEM(a,b,c,d) (a | (b << 4) | (c << 8) | (d << 12)) #else # define SIT_ITEM(a,b,c,d) (a | (b << 4) | (c << 8)) #endif static const uint16_t S_I_T[] ALIGN2 = { #if ENABLE_ASH_ALIAS SIT_ITEM(CSPCL , CIGN , CIGN , CIGN ), /* 0, PEOA */ #endif SIT_ITEM(CSPCL , CWORD , CWORD, CWORD ), /* 1, ' ' */ SIT_ITEM(CNL , CNL , CNL , CNL ), /* 2, \n */ SIT_ITEM(CWORD , CCTL , CCTL , CWORD ), /* 3, !*-/:=?[]~ */ SIT_ITEM(CDQUOTE , CENDQUOTE, CWORD, CWORD ), /* 4, '"' */ SIT_ITEM(CVAR , CVAR , CWORD, CVAR ), /* 5, $ */ SIT_ITEM(CSQUOTE , CWORD , CENDQUOTE, CWORD), /* 6, "'" */ SIT_ITEM(CSPCL , CWORD , CWORD, CLP ), /* 7, ( */ SIT_ITEM(CSPCL , CWORD , CWORD, CRP ), /* 8, ) */ SIT_ITEM(CBACK , CBACK , CCTL , CBACK ), /* 9, \ */ SIT_ITEM(CBQUOTE , CBQUOTE , CWORD, CBQUOTE), /* 10, ` */ SIT_ITEM(CENDVAR , CENDVAR , CWORD, CENDVAR), /* 11, } */ #if !USE_SIT_FUNCTION SIT_ITEM(CENDFILE, CENDFILE , CENDFILE, CENDFILE),/* 12, PEOF */ SIT_ITEM(CWORD , CWORD , CWORD, CWORD ), /* 13, 0-9A-Za-z */ SIT_ITEM(CCTL , CCTL , CCTL , CCTL ) /* 14, CTLESC ... */ #endif #undef SIT_ITEM }; /* Constants below must match table above */ enum { #if ENABLE_ASH_ALIAS CSPCL_CIGN_CIGN_CIGN , /* 0 */ #endif CSPCL_CWORD_CWORD_CWORD , /* 1 */ CNL_CNL_CNL_CNL , /* 2 */ CWORD_CCTL_CCTL_CWORD , /* 3 */ CDQUOTE_CENDQUOTE_CWORD_CWORD , /* 4 */ CVAR_CVAR_CWORD_CVAR , /* 5 */ CSQUOTE_CWORD_CENDQUOTE_CWORD , /* 6 */ CSPCL_CWORD_CWORD_CLP , /* 7 */ CSPCL_CWORD_CWORD_CRP , /* 8 */ CBACK_CBACK_CCTL_CBACK , /* 9 */ CBQUOTE_CBQUOTE_CWORD_CBQUOTE , /* 10 */ CENDVAR_CENDVAR_CWORD_CENDVAR , /* 11 */ CENDFILE_CENDFILE_CENDFILE_CENDFILE, /* 12 */ CWORD_CWORD_CWORD_CWORD , /* 13 */ CCTL_CCTL_CCTL_CCTL , /* 14 */ }; /* c in SIT(c, syntax) must be an *unsigned char* or PEOA or PEOF, * caller must ensure proper cast on it if c is *char_ptr! */ /* Values for syntax param */ #define BASESYNTAX 0 /* not in quotes */ #define DQSYNTAX 1 /* in double quotes */ #define SQSYNTAX 2 /* in single quotes */ #define ARISYNTAX 3 /* in arithmetic */ #define PSSYNTAX 4 /* prompt. never passed to SIT() */ #if USE_SIT_FUNCTION static int SIT(int c, int syntax) { /* Used to also have '/' in this string: "\t\n !\"$&'()*-/:;<=>?[\\]`|}~" */ static const char spec_symbls[] ALIGN1 = "\t\n !\"$&'()*-:;<=>?[\\]`|}~"; /* * This causes '/' to be prepended with CTLESC in dquoted string, * making "./file"* treated incorrectly because we feed * ".\/file*" string to glob(), confusing it (see expandmeta func). * The "homegrown" glob implementation is okay with that, * but glibc one isn't. With '/' always treated as CWORD, * both work fine. */ # if ENABLE_ASH_ALIAS static const uint8_t syntax_index_table[] ALIGN1 = { 1, 2, 1, 3, 4, 5, 1, 6, /* "\t\n !\"$&'" */ 7, 8, 3, 3,/*3,*/3, 1, 1, /* "()*-/:;<" */ 3, 1, 3, 3, 9, 3, 10, 1, /* "=>?[\\]`|" */ 11, 3 /* "}~" */ }; # else static const uint8_t syntax_index_table[] ALIGN1 = { 0, 1, 0, 2, 3, 4, 0, 5, /* "\t\n !\"$&'" */ 6, 7, 2, 2,/*2,*/2, 0, 0, /* "()*-/:;<" */ 2, 0, 2, 2, 8, 2, 9, 0, /* "=>?[\\]`|" */ 10, 2 /* "}~" */ }; # endif const char *s; int indx; if (c == PEOF) return CENDFILE; # if ENABLE_ASH_ALIAS if (c == PEOA) indx = 0; else # endif { /* Cast is purely for paranoia here, * just in case someone passed signed char to us */ if ((unsigned char)c >= CTL_FIRST && (unsigned char)c <= CTL_LAST ) { return CCTL; } s = strchrnul(spec_symbls, c); if (*s == '\0') return CWORD; indx = syntax_index_table[s - spec_symbls]; } return (S_I_T[indx] >> (syntax*4)) & 0xf; } #else /* !USE_SIT_FUNCTION */ static const uint8_t syntax_index_table[] ALIGN1 = { /* BASESYNTAX_DQSYNTAX_SQSYNTAX_ARISYNTAX */ /* 0 */ CWORD_CWORD_CWORD_CWORD, /* 1 */ CWORD_CWORD_CWORD_CWORD, /* 2 */ CWORD_CWORD_CWORD_CWORD, /* 3 */ CWORD_CWORD_CWORD_CWORD, /* 4 */ CWORD_CWORD_CWORD_CWORD, /* 5 */ CWORD_CWORD_CWORD_CWORD, /* 6 */ CWORD_CWORD_CWORD_CWORD, /* 7 */ CWORD_CWORD_CWORD_CWORD, /* 8 */ CWORD_CWORD_CWORD_CWORD, /* 9 "\t" */ CSPCL_CWORD_CWORD_CWORD, /* 10 "\n" */ CNL_CNL_CNL_CNL, /* 11 */ CWORD_CWORD_CWORD_CWORD, /* 12 */ CWORD_CWORD_CWORD_CWORD, /* 13 */ CWORD_CWORD_CWORD_CWORD, /* 14 */ CWORD_CWORD_CWORD_CWORD, /* 15 */ CWORD_CWORD_CWORD_CWORD, /* 16 */ CWORD_CWORD_CWORD_CWORD, /* 17 */ CWORD_CWORD_CWORD_CWORD, /* 18 */ CWORD_CWORD_CWORD_CWORD, /* 19 */ CWORD_CWORD_CWORD_CWORD, /* 20 */ CWORD_CWORD_CWORD_CWORD, /* 21 */ CWORD_CWORD_CWORD_CWORD, /* 22 */ CWORD_CWORD_CWORD_CWORD, /* 23 */ CWORD_CWORD_CWORD_CWORD, /* 24 */ CWORD_CWORD_CWORD_CWORD, /* 25 */ CWORD_CWORD_CWORD_CWORD, /* 26 */ CWORD_CWORD_CWORD_CWORD, /* 27 */ CWORD_CWORD_CWORD_CWORD, /* 28 */ CWORD_CWORD_CWORD_CWORD, /* 29 */ CWORD_CWORD_CWORD_CWORD, /* 30 */ CWORD_CWORD_CWORD_CWORD, /* 31 */ CWORD_CWORD_CWORD_CWORD, /* 32 " " */ CSPCL_CWORD_CWORD_CWORD, /* 33 "!" */ CWORD_CCTL_CCTL_CWORD, /* 34 """ */ CDQUOTE_CENDQUOTE_CWORD_CWORD, /* 35 "#" */ CWORD_CWORD_CWORD_CWORD, /* 36 "$" */ CVAR_CVAR_CWORD_CVAR, /* 37 "%" */ CWORD_CWORD_CWORD_CWORD, /* 38 "&" */ CSPCL_CWORD_CWORD_CWORD, /* 39 "'" */ CSQUOTE_CWORD_CENDQUOTE_CWORD, /* 40 "(" */ CSPCL_CWORD_CWORD_CLP, /* 41 ")" */ CSPCL_CWORD_CWORD_CRP, /* 42 "*" */ CWORD_CCTL_CCTL_CWORD, /* 43 "+" */ CWORD_CWORD_CWORD_CWORD, /* 44 "," */ CWORD_CWORD_CWORD_CWORD, /* 45 "-" */ CWORD_CCTL_CCTL_CWORD, /* 46 "." */ CWORD_CWORD_CWORD_CWORD, /* "/" was CWORD_CCTL_CCTL_CWORD, see comment in SIT() function why this is changed: */ /* 47 "/" */ CWORD_CWORD_CWORD_CWORD, /* 48 "0" */ CWORD_CWORD_CWORD_CWORD, /* 49 "1" */ CWORD_CWORD_CWORD_CWORD, /* 50 "2" */ CWORD_CWORD_CWORD_CWORD, /* 51 "3" */ CWORD_CWORD_CWORD_CWORD, /* 52 "4" */ CWORD_CWORD_CWORD_CWORD, /* 53 "5" */ CWORD_CWORD_CWORD_CWORD, /* 54 "6" */ CWORD_CWORD_CWORD_CWORD, /* 55 "7" */ CWORD_CWORD_CWORD_CWORD, /* 56 "8" */ CWORD_CWORD_CWORD_CWORD, /* 57 "9" */ CWORD_CWORD_CWORD_CWORD, /* 58 ":" */ CWORD_CCTL_CCTL_CWORD, /* 59 ";" */ CSPCL_CWORD_CWORD_CWORD, /* 60 "<" */ CSPCL_CWORD_CWORD_CWORD, /* 61 "=" */ CWORD_CCTL_CCTL_CWORD, /* 62 ">" */ CSPCL_CWORD_CWORD_CWORD, /* 63 "?" */ CWORD_CCTL_CCTL_CWORD, /* 64 "@" */ CWORD_CWORD_CWORD_CWORD, /* 65 "A" */ CWORD_CWORD_CWORD_CWORD, /* 66 "B" */ CWORD_CWORD_CWORD_CWORD, /* 67 "C" */ CWORD_CWORD_CWORD_CWORD, /* 68 "D" */ CWORD_CWORD_CWORD_CWORD, /* 69 "E" */ CWORD_CWORD_CWORD_CWORD, /* 70 "F" */ CWORD_CWORD_CWORD_CWORD, /* 71 "G" */ CWORD_CWORD_CWORD_CWORD, /* 72 "H" */ CWORD_CWORD_CWORD_CWORD, /* 73 "I" */ CWORD_CWORD_CWORD_CWORD, /* 74 "J" */ CWORD_CWORD_CWORD_CWORD, /* 75 "K" */ CWORD_CWORD_CWORD_CWORD, /* 76 "L" */ CWORD_CWORD_CWORD_CWORD, /* 77 "M" */ CWORD_CWORD_CWORD_CWORD, /* 78 "N" */ CWORD_CWORD_CWORD_CWORD, /* 79 "O" */ CWORD_CWORD_CWORD_CWORD, /* 80 "P" */ CWORD_CWORD_CWORD_CWORD, /* 81 "Q" */ CWORD_CWORD_CWORD_CWORD, /* 82 "R" */ CWORD_CWORD_CWORD_CWORD, /* 83 "S" */ CWORD_CWORD_CWORD_CWORD, /* 84 "T" */ CWORD_CWORD_CWORD_CWORD, /* 85 "U" */ CWORD_CWORD_CWORD_CWORD, /* 86 "V" */ CWORD_CWORD_CWORD_CWORD, /* 87 "W" */ CWORD_CWORD_CWORD_CWORD, /* 88 "X" */ CWORD_CWORD_CWORD_CWORD, /* 89 "Y" */ CWORD_CWORD_CWORD_CWORD, /* 90 "Z" */ CWORD_CWORD_CWORD_CWORD, /* 91 "[" */ CWORD_CCTL_CCTL_CWORD, /* 92 "\" */ CBACK_CBACK_CCTL_CBACK, /* 93 "]" */ CWORD_CCTL_CCTL_CWORD, /* 94 "^" */ CWORD_CWORD_CWORD_CWORD, /* 95 "_" */ CWORD_CWORD_CWORD_CWORD, /* 96 "`" */ CBQUOTE_CBQUOTE_CWORD_CBQUOTE, /* 97 "a" */ CWORD_CWORD_CWORD_CWORD, /* 98 "b" */ CWORD_CWORD_CWORD_CWORD, /* 99 "c" */ CWORD_CWORD_CWORD_CWORD, /* 100 "d" */ CWORD_CWORD_CWORD_CWORD, /* 101 "e" */ CWORD_CWORD_CWORD_CWORD, /* 102 "f" */ CWORD_CWORD_CWORD_CWORD, /* 103 "g" */ CWORD_CWORD_CWORD_CWORD, /* 104 "h" */ CWORD_CWORD_CWORD_CWORD, /* 105 "i" */ CWORD_CWORD_CWORD_CWORD, /* 106 "j" */ CWORD_CWORD_CWORD_CWORD, /* 107 "k" */ CWORD_CWORD_CWORD_CWORD, /* 108 "l" */ CWORD_CWORD_CWORD_CWORD, /* 109 "m" */ CWORD_CWORD_CWORD_CWORD, /* 110 "n" */ CWORD_CWORD_CWORD_CWORD, /* 111 "o" */ CWORD_CWORD_CWORD_CWORD, /* 112 "p" */ CWORD_CWORD_CWORD_CWORD, /* 113 "q" */ CWORD_CWORD_CWORD_CWORD, /* 114 "r" */ CWORD_CWORD_CWORD_CWORD, /* 115 "s" */ CWORD_CWORD_CWORD_CWORD, /* 116 "t" */ CWORD_CWORD_CWORD_CWORD, /* 117 "u" */ CWORD_CWORD_CWORD_CWORD, /* 118 "v" */ CWORD_CWORD_CWORD_CWORD, /* 119 "w" */ CWORD_CWORD_CWORD_CWORD, /* 120 "x" */ CWORD_CWORD_CWORD_CWORD, /* 121 "y" */ CWORD_CWORD_CWORD_CWORD, /* 122 "z" */ CWORD_CWORD_CWORD_CWORD, /* 123 "{" */ CWORD_CWORD_CWORD_CWORD, /* 124 "|" */ CSPCL_CWORD_CWORD_CWORD, /* 125 "}" */ CENDVAR_CENDVAR_CWORD_CENDVAR, /* 126 "~" */ CWORD_CCTL_CCTL_CWORD, /* 127 del */ CWORD_CWORD_CWORD_CWORD, /* 128 0x80 */ CWORD_CWORD_CWORD_CWORD, /* 129 CTLESC */ CCTL_CCTL_CCTL_CCTL, /* 130 CTLVAR */ CCTL_CCTL_CCTL_CCTL, /* 131 CTLENDVAR */ CCTL_CCTL_CCTL_CCTL, /* 132 CTLBACKQ */ CCTL_CCTL_CCTL_CCTL, /* 133 CTLQUOTE */ CCTL_CCTL_CCTL_CCTL, /* 134 CTLARI */ CCTL_CCTL_CCTL_CCTL, /* 135 CTLENDARI */ CCTL_CCTL_CCTL_CCTL, /* 136 CTLQUOTEMARK */ CCTL_CCTL_CCTL_CCTL, /* 137 */ CWORD_CWORD_CWORD_CWORD, /* 138 */ CWORD_CWORD_CWORD_CWORD, /* 139 */ CWORD_CWORD_CWORD_CWORD, /* 140 */ CWORD_CWORD_CWORD_CWORD, /* 141 */ CWORD_CWORD_CWORD_CWORD, /* 142 */ CWORD_CWORD_CWORD_CWORD, /* 143 */ CWORD_CWORD_CWORD_CWORD, /* 144 */ CWORD_CWORD_CWORD_CWORD, /* 145 */ CWORD_CWORD_CWORD_CWORD, /* 146 */ CWORD_CWORD_CWORD_CWORD, /* 147 */ CWORD_CWORD_CWORD_CWORD, /* 148 */ CWORD_CWORD_CWORD_CWORD, /* 149 */ CWORD_CWORD_CWORD_CWORD, /* 150 */ CWORD_CWORD_CWORD_CWORD, /* 151 */ CWORD_CWORD_CWORD_CWORD, /* 152 */ CWORD_CWORD_CWORD_CWORD, /* 153 */ CWORD_CWORD_CWORD_CWORD, /* 154 */ CWORD_CWORD_CWORD_CWORD, /* 155 */ CWORD_CWORD_CWORD_CWORD, /* 156 */ CWORD_CWORD_CWORD_CWORD, /* 157 */ CWORD_CWORD_CWORD_CWORD, /* 158 */ CWORD_CWORD_CWORD_CWORD, /* 159 */ CWORD_CWORD_CWORD_CWORD, /* 160 */ CWORD_CWORD_CWORD_CWORD, /* 161 */ CWORD_CWORD_CWORD_CWORD, /* 162 */ CWORD_CWORD_CWORD_CWORD, /* 163 */ CWORD_CWORD_CWORD_CWORD, /* 164 */ CWORD_CWORD_CWORD_CWORD, /* 165 */ CWORD_CWORD_CWORD_CWORD, /* 166 */ CWORD_CWORD_CWORD_CWORD, /* 167 */ CWORD_CWORD_CWORD_CWORD, /* 168 */ CWORD_CWORD_CWORD_CWORD, /* 169 */ CWORD_CWORD_CWORD_CWORD, /* 170 */ CWORD_CWORD_CWORD_CWORD, /* 171 */ CWORD_CWORD_CWORD_CWORD, /* 172 */ CWORD_CWORD_CWORD_CWORD, /* 173 */ CWORD_CWORD_CWORD_CWORD, /* 174 */ CWORD_CWORD_CWORD_CWORD, /* 175 */ CWORD_CWORD_CWORD_CWORD, /* 176 */ CWORD_CWORD_CWORD_CWORD, /* 177 */ CWORD_CWORD_CWORD_CWORD, /* 178 */ CWORD_CWORD_CWORD_CWORD, /* 179 */ CWORD_CWORD_CWORD_CWORD, /* 180 */ CWORD_CWORD_CWORD_CWORD, /* 181 */ CWORD_CWORD_CWORD_CWORD, /* 182 */ CWORD_CWORD_CWORD_CWORD, /* 183 */ CWORD_CWORD_CWORD_CWORD, /* 184 */ CWORD_CWORD_CWORD_CWORD, /* 185 */ CWORD_CWORD_CWORD_CWORD, /* 186 */ CWORD_CWORD_CWORD_CWORD, /* 187 */ CWORD_CWORD_CWORD_CWORD, /* 188 */ CWORD_CWORD_CWORD_CWORD, /* 189 */ CWORD_CWORD_CWORD_CWORD, /* 190 */ CWORD_CWORD_CWORD_CWORD, /* 191 */ CWORD_CWORD_CWORD_CWORD, /* 192 */ CWORD_CWORD_CWORD_CWORD, /* 193 */ CWORD_CWORD_CWORD_CWORD, /* 194 */ CWORD_CWORD_CWORD_CWORD, /* 195 */ CWORD_CWORD_CWORD_CWORD, /* 196 */ CWORD_CWORD_CWORD_CWORD, /* 197 */ CWORD_CWORD_CWORD_CWORD, /* 198 */ CWORD_CWORD_CWORD_CWORD, /* 199 */ CWORD_CWORD_CWORD_CWORD, /* 200 */ CWORD_CWORD_CWORD_CWORD, /* 201 */ CWORD_CWORD_CWORD_CWORD, /* 202 */ CWORD_CWORD_CWORD_CWORD, /* 203 */ CWORD_CWORD_CWORD_CWORD, /* 204 */ CWORD_CWORD_CWORD_CWORD, /* 205 */ CWORD_CWORD_CWORD_CWORD, /* 206 */ CWORD_CWORD_CWORD_CWORD, /* 207 */ CWORD_CWORD_CWORD_CWORD, /* 208 */ CWORD_CWORD_CWORD_CWORD, /* 209 */ CWORD_CWORD_CWORD_CWORD, /* 210 */ CWORD_CWORD_CWORD_CWORD, /* 211 */ CWORD_CWORD_CWORD_CWORD, /* 212 */ CWORD_CWORD_CWORD_CWORD, /* 213 */ CWORD_CWORD_CWORD_CWORD, /* 214 */ CWORD_CWORD_CWORD_CWORD, /* 215 */ CWORD_CWORD_CWORD_CWORD, /* 216 */ CWORD_CWORD_CWORD_CWORD, /* 217 */ CWORD_CWORD_CWORD_CWORD, /* 218 */ CWORD_CWORD_CWORD_CWORD, /* 219 */ CWORD_CWORD_CWORD_CWORD, /* 220 */ CWORD_CWORD_CWORD_CWORD, /* 221 */ CWORD_CWORD_CWORD_CWORD, /* 222 */ CWORD_CWORD_CWORD_CWORD, /* 223 */ CWORD_CWORD_CWORD_CWORD, /* 224 */ CWORD_CWORD_CWORD_CWORD, /* 225 */ CWORD_CWORD_CWORD_CWORD, /* 226 */ CWORD_CWORD_CWORD_CWORD, /* 227 */ CWORD_CWORD_CWORD_CWORD, /* 228 */ CWORD_CWORD_CWORD_CWORD, /* 229 */ CWORD_CWORD_CWORD_CWORD, /* 230 */ CWORD_CWORD_CWORD_CWORD, /* 231 */ CWORD_CWORD_CWORD_CWORD, /* 232 */ CWORD_CWORD_CWORD_CWORD, /* 233 */ CWORD_CWORD_CWORD_CWORD, /* 234 */ CWORD_CWORD_CWORD_CWORD, /* 235 */ CWORD_CWORD_CWORD_CWORD, /* 236 */ CWORD_CWORD_CWORD_CWORD, /* 237 */ CWORD_CWORD_CWORD_CWORD, /* 238 */ CWORD_CWORD_CWORD_CWORD, /* 239 */ CWORD_CWORD_CWORD_CWORD, /* 230 */ CWORD_CWORD_CWORD_CWORD, /* 241 */ CWORD_CWORD_CWORD_CWORD, /* 242 */ CWORD_CWORD_CWORD_CWORD, /* 243 */ CWORD_CWORD_CWORD_CWORD, /* 244 */ CWORD_CWORD_CWORD_CWORD, /* 245 */ CWORD_CWORD_CWORD_CWORD, /* 246 */ CWORD_CWORD_CWORD_CWORD, /* 247 */ CWORD_CWORD_CWORD_CWORD, /* 248 */ CWORD_CWORD_CWORD_CWORD, /* 249 */ CWORD_CWORD_CWORD_CWORD, /* 250 */ CWORD_CWORD_CWORD_CWORD, /* 251 */ CWORD_CWORD_CWORD_CWORD, /* 252 */ CWORD_CWORD_CWORD_CWORD, /* 253 */ CWORD_CWORD_CWORD_CWORD, /* 254 */ CWORD_CWORD_CWORD_CWORD, /* 255 */ CWORD_CWORD_CWORD_CWORD, /* PEOF */ CENDFILE_CENDFILE_CENDFILE_CENDFILE, # if ENABLE_ASH_ALIAS /* PEOA */ CSPCL_CIGN_CIGN_CIGN, # endif }; #if 1 # define SIT(c, syntax) ((S_I_T[syntax_index_table[c]] >> ((syntax)*4)) & 0xf) #else /* debug version, caught one signed char bug */ # define SIT(c, syntax) \ ({ \ if ((c) < 0 || (c) > (PEOF + ENABLE_ASH_ALIAS)) \ bb_error_msg_and_die("line:%d c:%d", __LINE__, (c)); \ if ((syntax) < 0 || (syntax) > (2 + ENABLE_FEATURE_SH_MATH)) \ bb_error_msg_and_die("line:%d c:%d", __LINE__, (c)); \ ((S_I_T[syntax_index_table[c]] >> ((syntax)*4)) & 0xf); \ }) #endif #endif /* !USE_SIT_FUNCTION */ /* ============ Alias handling */ #if ENABLE_ASH_ALIAS #define ALIASINUSE 1 #define ALIASDEAD 2 struct alias { struct alias *next; char *name; char *val; int flag; }; static struct alias **atab; // [ATABSIZE]; #define INIT_G_alias() do { \ atab = xzalloc(ATABSIZE * sizeof(atab[0])); \ } while (0) static struct alias ** __lookupalias(const char *name) { unsigned int hashval; struct alias **app; const char *p; unsigned int ch; p = name; ch = (unsigned char)*p; hashval = ch << 4; while (ch) { hashval += ch; ch = (unsigned char)*++p; } app = &atab[hashval % ATABSIZE]; for (; *app; app = &(*app)->next) { if (strcmp(name, (*app)->name) == 0) { break; } } return app; } static struct alias * lookupalias(const char *name, int check) { struct alias *ap = *__lookupalias(name); if (check && ap && (ap->flag & ALIASINUSE)) return NULL; return ap; } static struct alias * freealias(struct alias *ap) { struct alias *next; if (ap->flag & ALIASINUSE) { ap->flag |= ALIASDEAD; return ap; } next = ap->next; free(ap->name); free(ap->val); free(ap); return next; } static void setalias(const char *name, const char *val) { struct alias *ap, **app; app = __lookupalias(name); ap = *app; INT_OFF; if (ap) { if (!(ap->flag & ALIASINUSE)) { free(ap->val); } ap->val = ckstrdup(val); ap->flag &= ~ALIASDEAD; } else { /* not found */ ap = ckzalloc(sizeof(struct alias)); ap->name = ckstrdup(name); ap->val = ckstrdup(val); /*ap->flag = 0; - ckzalloc did it */ /*ap->next = NULL;*/ *app = ap; } INT_ON; } static int unalias(const char *name) { struct alias **app; app = __lookupalias(name); if (*app) { INT_OFF; *app = freealias(*app); INT_ON; return 0; } return 1; } static void rmaliases(void) { struct alias *ap, **app; int i; INT_OFF; for (i = 0; i < ATABSIZE; i++) { app = &atab[i]; for (ap = *app; ap; ap = *app) { *app = freealias(*app); if (ap == *app) { app = &ap->next; } } } INT_ON; } static void printalias(const struct alias *ap) { out1fmt("%s=%s\n", ap->name, single_quote(ap->val)); } /* * TODO - sort output */ static int FAST_FUNC aliascmd(int argc UNUSED_PARAM, char **argv) { char *n, *v; int ret = 0; struct alias *ap; if (!argv[1]) { int i; for (i = 0; i < ATABSIZE; i++) { for (ap = atab[i]; ap; ap = ap->next) { printalias(ap); } } return 0; } while ((n = *++argv) != NULL) { v = strchr(n+1, '='); if (v == NULL) { /* n+1: funny ksh stuff */ ap = *__lookupalias(n); if (ap == NULL) { fprintf(stderr, "%s: %s not found\n", "alias", n); ret = 1; } else printalias(ap); } else { *v++ = '\0'; setalias(n, v); } } return ret; } static int FAST_FUNC unaliascmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { int i; while (nextopt("a") != '\0') { rmaliases(); return 0; } for (i = 0; *argptr; argptr++) { if (unalias(*argptr)) { fprintf(stderr, "%s: %s not found\n", "unalias", *argptr); i = 1; } } return i; } #endif /* ASH_ALIAS */ /* Mode argument to forkshell. Don't change FORK_FG or FORK_BG. */ #define FORK_FG 0 #define FORK_BG 1 #define FORK_NOJOB 2 /* mode flags for showjob(s) */ #define SHOW_ONLY_PGID 0x01 /* show only pgid (jobs -p) */ #define SHOW_PIDS 0x02 /* show individual pids, not just one line per job */ #define SHOW_CHANGED 0x04 /* only jobs whose state has changed */ #define SHOW_STDERR 0x08 /* print to stderr (else stdout) */ /* * A job structure contains information about a job. A job is either a * single process or a set of processes contained in a pipeline. In the * latter case, pidlist will be non-NULL, and will point to a -1 terminated * array of pids. */ struct procstat { pid_t ps_pid; /* process id */ int ps_status; /* last process status from wait() */ char *ps_cmd; /* text of command being run */ }; struct job { struct procstat ps0; /* status of process */ struct procstat *ps; /* status or processes when more than one */ #if JOBS int stopstatus; /* status of a stopped job */ #endif unsigned nprocs; /* number of processes */ #define JOBRUNNING 0 /* at least one proc running */ #define JOBSTOPPED 1 /* all procs are stopped */ #define JOBDONE 2 /* all procs are completed */ unsigned state: 8, #if JOBS sigint: 1, /* job was killed by SIGINT */ jobctl: 1, /* job running under job control */ #endif waited: 1, /* true if this entry has been waited for */ used: 1, /* true if this entry is in used */ changed: 1; /* true if status has changed */ struct job *prev_job; /* previous job */ }; static struct job *makejob(/*union node *,*/ int); static int forkshell(struct job *, union node *, int); static int waitforjob(struct job *); #if !JOBS enum { doing_jobctl = 0 }; #define setjobctl(on) do {} while (0) #else static smallint doing_jobctl; //references:8 static void setjobctl(int); #endif /* * Ignore a signal. */ static void ignoresig(int signo) { /* Avoid unnecessary system calls. Is it already SIG_IGNed? */ if (sigmode[signo - 1] != S_IGN && sigmode[signo - 1] != S_HARD_IGN) { /* No, need to do it */ signal(signo, SIG_IGN); } sigmode[signo - 1] = S_HARD_IGN; } /* * Only one usage site - in setsignal() */ static void signal_handler(int signo) { if (signo == SIGCHLD) { got_sigchld = 1; if (!trap[SIGCHLD]) return; } gotsig[signo - 1] = 1; pending_sig = signo; if (signo == SIGINT && !trap[SIGINT]) { if (!suppress_int) { pending_sig = 0; raise_interrupt(); /* does not return */ } pending_int = 1; } } /* * Set the signal handler for the specified signal. The routine figures * out what it should be set to. */ static void setsignal(int signo) { char *t; char cur_act, new_act; struct sigaction act; t = trap[signo]; new_act = S_DFL; if (t != NULL) { /* trap for this sig is set */ new_act = S_CATCH; if (t[0] == '\0') /* trap is "": ignore this sig */ new_act = S_IGN; } if (rootshell && new_act == S_DFL) { switch (signo) { case SIGINT: if (iflag || minusc || sflag == 0) new_act = S_CATCH; break; case SIGQUIT: #if DEBUG if (debug) break; #endif /* man bash: * "In all cases, bash ignores SIGQUIT. Non-builtin * commands run by bash have signal handlers * set to the values inherited by the shell * from its parent". */ new_act = S_IGN; break; case SIGTERM: if (iflag) new_act = S_IGN; break; #if JOBS case SIGTSTP: case SIGTTOU: if (mflag) new_act = S_IGN; break; #endif } } //TODO: if !rootshell, we reset SIGQUIT to DFL, //whereas we have to restore it to what shell got on entry //from the parent. See comment above if (signo == SIGCHLD) new_act = S_CATCH; t = &sigmode[signo - 1]; cur_act = *t; if (cur_act == 0) { /* current setting is not yet known */ if (sigaction(signo, NULL, &act)) { /* pretend it worked; maybe we should give a warning, * but other shells don't. We don't alter sigmode, * so we retry every time. * btw, in Linux it never fails. --vda */ return; } if (act.sa_handler == SIG_IGN) { cur_act = S_HARD_IGN; if (mflag && (signo == SIGTSTP || signo == SIGTTIN || signo == SIGTTOU) ) { cur_act = S_IGN; /* don't hard ignore these */ } } } if (cur_act == S_HARD_IGN || cur_act == new_act) return; act.sa_handler = SIG_DFL; switch (new_act) { case S_CATCH: act.sa_handler = signal_handler; break; case S_IGN: act.sa_handler = SIG_IGN; break; } /* flags and mask matter only if !DFL and !IGN, but we do it * for all cases for more deterministic behavior: */ act.sa_flags = 0; sigfillset(&act.sa_mask); sigaction_set(signo, &act); *t = new_act; } /* mode flags for set_curjob */ #define CUR_DELETE 2 #define CUR_RUNNING 1 #define CUR_STOPPED 0 #if JOBS /* pgrp of shell on invocation */ static int initialpgrp; //references:2 static int ttyfd = -1; //5 #endif /* array of jobs */ static struct job *jobtab; //5 /* size of array */ static unsigned njobs; //4 /* current job */ static struct job *curjob; //lots /* number of presumed living untracked jobs */ static int jobless; //4 #if 0 /* Bash has a feature: it restores termios after a successful wait for * a foreground job which had at least one stopped or sigkilled member. * The probable rationale is that SIGSTOP and SIGKILL can preclude task from * properly restoring tty state. Should we do this too? * A reproducer: ^Z an interactive python: * * # python * Python 2.7.12 (...) * >>> ^Z * { python leaves tty in -icanon -echo state. We do survive that... } * [1]+ Stopped python * { ...however, next program (python #2) does not survive it well: } * # python * Python 2.7.12 (...) * >>> Traceback (most recent call last): * { above, I typed "qwerty", but -echo state is still in effect } * File "", line 1, in * NameError: name 'qwerty' is not defined * * The implementation below is modeled on bash code and seems to work. * However, I'm not sure we should do this. For one: what if I'd fg * the stopped python instead? It'll be confused by "restored" tty state. */ static struct termios shell_tty_info; static void get_tty_state(void) { if (rootshell && ttyfd >= 0) tcgetattr(ttyfd, &shell_tty_info); } static void set_tty_state(void) { /* if (rootshell) - caller ensures this */ if (ttyfd >= 0) tcsetattr(ttyfd, TCSADRAIN, &shell_tty_info); } static int job_signal_status(struct job *jp) { int status; unsigned i; struct procstat *ps = jp->ps; for (i = 0; i < jp->nprocs; i++) { status = ps[i].ps_status; if (WIFSIGNALED(status) || WIFSTOPPED(status)) return status; } return 0; } static void restore_tty_if_stopped_or_signaled(struct job *jp) { //TODO: check what happens if we come from waitforjob() in expbackq() if (rootshell) { int s = job_signal_status(jp); if (s) /* WIFSIGNALED(s) || WIFSTOPPED(s) */ set_tty_state(); } } #else # define get_tty_state() ((void)0) # define restore_tty_if_stopped_or_signaled(jp) ((void)0) #endif static void set_curjob(struct job *jp, unsigned mode) { struct job *jp1; struct job **jpp, **curp; /* first remove from list */ jpp = curp = &curjob; while (1) { jp1 = *jpp; if (jp1 == jp) break; jpp = &jp1->prev_job; } *jpp = jp1->prev_job; /* Then re-insert in correct position */ jpp = curp; switch (mode) { default: #if DEBUG abort(); #endif case CUR_DELETE: /* job being deleted */ break; case CUR_RUNNING: /* newly created job or backgrounded job, * put after all stopped jobs. */ while (1) { jp1 = *jpp; #if JOBS if (!jp1 || jp1->state != JOBSTOPPED) #endif break; jpp = &jp1->prev_job; } /* FALLTHROUGH */ #if JOBS case CUR_STOPPED: #endif /* newly stopped job - becomes curjob */ jp->prev_job = *jpp; *jpp = jp; break; } } #if JOBS || DEBUG static int jobno(const struct job *jp) { return jp - jobtab + 1; } #endif /* * Convert a job name to a job structure. */ #if !JOBS #define getjob(name, getctl) getjob(name) #endif static struct job * getjob(const char *name, int getctl) { struct job *jp; struct job *found; const char *err_msg = "%s: no such job"; unsigned num; int c; const char *p; char *(*match)(const char *, const char *); jp = curjob; p = name; if (!p) goto currentjob; if (*p != '%') goto err; c = *++p; if (!c) goto currentjob; if (!p[1]) { if (c == '+' || c == '%') { currentjob: err_msg = "No current job"; goto check; } if (c == '-') { if (jp) jp = jp->prev_job; err_msg = "No previous job"; check: if (!jp) goto err; goto gotit; } } if (is_number(p)) { num = atoi(p); if (num > 0 && num <= njobs) { jp = jobtab + num - 1; if (jp->used) goto gotit; goto err; } } match = prefix; if (*p == '?') { match = strstr; p++; } found = NULL; while (jp) { if (match(jp->ps[0].ps_cmd, p)) { if (found) goto err; found = jp; err_msg = "%s: ambiguous"; } jp = jp->prev_job; } if (!found) goto err; jp = found; gotit: #if JOBS err_msg = "job %s not created under job control"; if (getctl && jp->jobctl == 0) goto err; #endif return jp; err: ash_msg_and_raise_error(err_msg, name); } /* * Mark a job structure as unused. */ static void freejob(struct job *jp) { struct procstat *ps; int i; INT_OFF; for (i = jp->nprocs, ps = jp->ps; --i >= 0; ps++) { if (ps->ps_cmd != nullstr) free(ps->ps_cmd); } if (jp->ps != &jp->ps0) free(jp->ps); jp->used = 0; set_curjob(jp, CUR_DELETE); INT_ON; } #if JOBS static void xtcsetpgrp(int fd, pid_t pgrp) { if (tcsetpgrp(fd, pgrp)) ash_msg_and_raise_error("can't set tty process group (%m)"); } /* * Turn job control on and off. * * Note: This code assumes that the third arg to ioctl is a character * pointer, which is true on Berkeley systems but not System V. Since * System V doesn't have job control yet, this isn't a problem now. * * Called with interrupts off. */ static void setjobctl(int on) { int fd; int pgrp; if (on == doing_jobctl || rootshell == 0) return; if (on) { int ofd; ofd = fd = open(_PATH_TTY, O_RDWR); if (fd < 0) { /* BTW, bash will try to open(ttyname(0)) if open("/dev/tty") fails. * That sometimes helps to acquire controlling tty. * Obviously, a workaround for bugs when someone * failed to provide a controlling tty to bash! :) */ fd = 2; while (!isatty(fd)) if (--fd < 0) goto out; } /* fd is a tty at this point */ fd = fcntl(fd, F_DUPFD, 10); if (ofd >= 0) /* if it is "/dev/tty", close. If 0/1/2, don't */ close(ofd); if (fd < 0) goto out; /* F_DUPFD failed */ close_on_exec_on(fd); while (1) { /* while we are in the background */ pgrp = tcgetpgrp(fd); if (pgrp < 0) { out: ash_msg("can't access tty; job control turned off"); mflag = on = 0; goto close; } if (pgrp == getpgrp()) break; killpg(0, SIGTTIN); } initialpgrp = pgrp; setsignal(SIGTSTP); setsignal(SIGTTOU); setsignal(SIGTTIN); pgrp = rootpid; setpgid(0, pgrp); xtcsetpgrp(fd, pgrp); } else { /* turning job control off */ fd = ttyfd; pgrp = initialpgrp; /* was xtcsetpgrp, but this can make exiting ash * loop forever if pty is already deleted */ tcsetpgrp(fd, pgrp); setpgid(0, pgrp); setsignal(SIGTSTP); setsignal(SIGTTOU); setsignal(SIGTTIN); close: if (fd >= 0) close(fd); fd = -1; } ttyfd = fd; doing_jobctl = on; } static int FAST_FUNC killcmd(int argc, char **argv) { if (argv[1] && strcmp(argv[1], "-l") != 0) { int i = 1; do { if (argv[i][0] == '%') { /* * "kill %N" - job kill * Converting to pgrp / pid kill */ struct job *jp; char *dst; int j, n; jp = getjob(argv[i], 0); /* * 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 = jp->nprocs; /* can't be 0 (I hope) */ if (jp->jobctl) n = 1; dst = alloca(n * sizeof(int)*4); argv[i] = dst; for (j = 0; j < n; j++) { struct procstat *ps = &jp->ps[j]; /* Skip non-running and not-stopped members * (i.e. dead members) of the job */ if (ps->ps_status != -1 && !WIFSTOPPED(ps->ps_status)) continue; /* * kill_main has matching code to expect * leading space. Needed to not confuse * negative pids with "kill -SIGNAL_NO" syntax */ dst += sprintf(dst, jp->jobctl ? " -%u" : " %u", (int)ps->ps_pid); } *dst = '\0'; } } while (argv[++i]); } return kill_main(argc, argv); } static void showpipe(struct job *jp /*, FILE *out*/) { struct procstat *ps; struct procstat *psend; psend = jp->ps + jp->nprocs; for (ps = jp->ps + 1; ps < psend; ps++) printf(" | %s", ps->ps_cmd); newline_and_flush(stdout); flush_stdout_stderr(); } static int restartjob(struct job *jp, int mode) { struct procstat *ps; int i; int status; pid_t pgid; INT_OFF; if (jp->state == JOBDONE) goto out; jp->state = JOBRUNNING; pgid = jp->ps[0].ps_pid; if (mode == FORK_FG) { get_tty_state(); xtcsetpgrp(ttyfd, pgid); } killpg(pgid, SIGCONT); ps = jp->ps; i = jp->nprocs; do { if (WIFSTOPPED(ps->ps_status)) { ps->ps_status = -1; } ps++; } while (--i); out: status = (mode == FORK_FG) ? waitforjob(jp) : 0; INT_ON; return status; } static int FAST_FUNC fg_bgcmd(int argc UNUSED_PARAM, char **argv) { struct job *jp; int mode; int retval; mode = (**argv == 'f') ? FORK_FG : FORK_BG; nextopt(nullstr); argv = argptr; do { jp = getjob(*argv, 1); if (mode == FORK_BG) { set_curjob(jp, CUR_RUNNING); printf("[%d] ", jobno(jp)); } out1str(jp->ps[0].ps_cmd); showpipe(jp /*, stdout*/); retval = restartjob(jp, mode); } while (*argv && *++argv); return retval; } #endif static int sprint_status48(char *s, int status, int sigonly) { int col; int st; col = 0; if (!WIFEXITED(status)) { if (JOBS && WIFSTOPPED(status)) st = WSTOPSIG(status); else st = WTERMSIG(status); if (sigonly) { if (st == SIGINT || st == SIGPIPE) goto out; if (JOBS && WIFSTOPPED(status)) goto out; } st &= 0x7f; //TODO: use bbox's get_signame? strsignal adds ~600 bytes to text+rodata col = fmtstr(s, 32, strsignal(st)); if (WCOREDUMP(status)) { strcpy(s + col, " (core dumped)"); col += sizeof(" (core dumped)")-1; } } else if (!sigonly) { st = WEXITSTATUS(status); col = fmtstr(s, 16, (st ? "Done(%d)" : "Done"), st); } out: return col; } static int wait_block_or_sig(int *status) { int pid; do { sigset_t mask; /* Poll all children for changes in their state */ got_sigchld = 0; /* if job control is active, accept stopped processes too */ pid = waitpid(-1, status, doing_jobctl ? (WNOHANG|WUNTRACED) : WNOHANG); if (pid != 0) break; /* Error (e.g. EINTR, ECHILD) or pid */ /* Children exist, but none are ready. Sleep until interesting signal */ #if 1 sigfillset(&mask); sigprocmask(SIG_SETMASK, &mask, &mask); while (!got_sigchld && !pending_sig) sigsuspend(&mask); sigprocmask(SIG_SETMASK, &mask, NULL); #else /* unsafe: a signal can set pending_sig after check, but before pause() */ while (!got_sigchld && !pending_sig) pause(); #endif /* If it was SIGCHLD, poll children again */ } while (got_sigchld); return pid; } #define DOWAIT_NONBLOCK 0 #define DOWAIT_BLOCK 1 #define DOWAIT_BLOCK_OR_SIG 2 static int dowait(int block, struct job *job) { int pid; int status; struct job *jp; struct job *thisjob = NULL; TRACE(("dowait(0x%x) called\n", block)); /* It's wrong to call waitpid() outside of INT_OFF region: * signal can arrive just after syscall return and handler can * longjmp away, losing stop/exit notification processing. * Thus, for "jobs" builtin, and for waiting for a fg job, * we call waitpid() (blocking or non-blocking) inside INT_OFF. * * However, for "wait" builtin it is wrong to simply call waitpid() * in INT_OFF region: "wait" needs to wait for any running job * to change state, but should exit on any trap too. * In INT_OFF region, a signal just before syscall entry can set * pending_sig variables, but we can't check them, and we would * either enter a sleeping waitpid() (BUG), or need to busy-loop. * * Because of this, we run inside INT_OFF, but use a special routine * which combines waitpid() and sigsuspend(). * This is the reason why we need to have a handler for SIGCHLD: * SIG_DFL handler does not wake sigsuspend(). */ INT_OFF; if (block == DOWAIT_BLOCK_OR_SIG) { pid = wait_block_or_sig(&status); } else { int wait_flags = 0; if (block == DOWAIT_NONBLOCK) wait_flags = WNOHANG; /* if job control is active, accept stopped processes too */ if (doing_jobctl) wait_flags |= WUNTRACED; /* NB: _not_ safe_waitpid, we need to detect EINTR */ pid = waitpid(-1, &status, wait_flags); } TRACE(("wait returns pid=%d, status=0x%x, errno=%d(%s)\n", pid, status, errno, strerror(errno))); if (pid <= 0) goto out; thisjob = NULL; for (jp = curjob; jp; jp = jp->prev_job) { int jobstate; struct procstat *ps; struct procstat *psend; if (jp->state == JOBDONE) continue; jobstate = JOBDONE; ps = jp->ps; psend = ps + jp->nprocs; do { if (ps->ps_pid == pid) { TRACE(("Job %d: changing status of proc %d " "from 0x%x to 0x%x\n", jobno(jp), pid, ps->ps_status, status)); ps->ps_status = status; thisjob = jp; } if (ps->ps_status == -1) jobstate = JOBRUNNING; #if JOBS if (jobstate == JOBRUNNING) continue; if (WIFSTOPPED(ps->ps_status)) { jp->stopstatus = ps->ps_status; jobstate = JOBSTOPPED; } #endif } while (++ps < psend); if (!thisjob) continue; /* Found the job where one of its processes changed its state. * Is there at least one live and running process in this job? */ if (jobstate != JOBRUNNING) { /* No. All live processes in the job are stopped * (JOBSTOPPED) or there are no live processes (JOBDONE) */ thisjob->changed = 1; if (thisjob->state != jobstate) { TRACE(("Job %d: changing state from %d to %d\n", jobno(thisjob), thisjob->state, jobstate)); thisjob->state = jobstate; #if JOBS if (jobstate == JOBSTOPPED) set_curjob(thisjob, CUR_STOPPED); #endif } } goto out; } /* The process wasn't found in job list */ if (JOBS && !WIFSTOPPED(status)) jobless--; out: INT_ON; if (thisjob && thisjob == job) { char s[48 + 1]; int len; len = sprint_status48(s, status, 1); if (len) { s[len] = '\n'; s[len + 1] = '\0'; out2str(s); } } return pid; } #if JOBS static void showjob(struct job *jp, int mode) { struct procstat *ps; struct procstat *psend; int col; int indent_col; char s[16 + 16 + 48]; FILE *out = (mode & SHOW_STDERR ? stderr : stdout); ps = jp->ps; if (mode & SHOW_ONLY_PGID) { /* jobs -p */ /* just output process (group) id of pipeline */ fprintf(out, "%d\n", ps->ps_pid); return; } col = fmtstr(s, 16, "[%d] ", jobno(jp)); indent_col = col; if (jp == curjob) s[col - 3] = '+'; else if (curjob && jp == curjob->prev_job) s[col - 3] = '-'; if (mode & SHOW_PIDS) col += fmtstr(s + col, 16, "%d ", ps->ps_pid); psend = ps + jp->nprocs; if (jp->state == JOBRUNNING) { strcpy(s + col, "Running"); col += sizeof("Running") - 1; } else { int status = psend[-1].ps_status; if (jp->state == JOBSTOPPED) status = jp->stopstatus; col += sprint_status48(s + col, status, 0); } /* By now, "[JOBID]* [maybe PID] STATUS" is printed */ /* This loop either prints " | | " line * or prints several "PID | " lines, * depending on SHOW_PIDS bit. * We do not print status of individual processes * between PID and . bash does it, but not very well: * first line shows overall job status, not process status, * making it impossible to know 1st process status. */ goto start; do { /* for each process */ s[0] = '\0'; col = 33; if (mode & SHOW_PIDS) col = fmtstr(s, 48, "\n%*c%d ", indent_col, ' ', ps->ps_pid) - 1; start: fprintf(out, "%s%*c%s%s", s, 33 - col >= 0 ? 33 - col : 0, ' ', ps == jp->ps ? "" : "| ", ps->ps_cmd ); } while (++ps != psend); newline_and_flush(out); jp->changed = 0; if (jp->state == JOBDONE) { TRACE(("showjob: freeing job %d\n", jobno(jp))); freejob(jp); } } /* * Print a list of jobs. If "change" is nonzero, only print jobs whose * statuses have changed since the last call to showjobs. */ static void showjobs(int mode) { struct job *jp; TRACE(("showjobs(0x%x) called\n", mode)); /* Handle all finished jobs */ while (dowait(DOWAIT_NONBLOCK, NULL) > 0) continue; for (jp = curjob; jp; jp = jp->prev_job) { if (!(mode & SHOW_CHANGED) || jp->changed) { showjob(jp, mode); } } } static int FAST_FUNC jobscmd(int argc UNUSED_PARAM, char **argv) { int mode, m; mode = 0; while ((m = nextopt("lp")) != '\0') { if (m == 'l') mode |= SHOW_PIDS; else mode |= SHOW_ONLY_PGID; } argv = argptr; if (*argv) { do showjob(getjob(*argv, 0), mode); while (*++argv); } else { showjobs(mode); } return 0; } #endif /* JOBS */ /* Called only on finished or stopped jobs (no members are running) */ static int getstatus(struct job *job) { int status; int retval; struct procstat *ps; /* Fetch last member's status */ ps = job->ps + job->nprocs - 1; status = ps->ps_status; if (pipefail) { /* "set -o pipefail" mode: use last _nonzero_ status */ while (status == 0 && --ps >= job->ps) status = ps->ps_status; } retval = WEXITSTATUS(status); if (!WIFEXITED(status)) { #if JOBS retval = WSTOPSIG(status); if (!WIFSTOPPED(status)) #endif { /* XXX: limits number of signals */ retval = WTERMSIG(status); #if JOBS if (retval == SIGINT) job->sigint = 1; #endif } retval += 128; } TRACE(("getstatus: job %d, nproc %d, status 0x%x, retval 0x%x\n", jobno(job), job->nprocs, status, retval)); return retval; } static int FAST_FUNC waitcmd(int argc UNUSED_PARAM, char **argv) { struct job *job; int retval; struct job *jp; nextopt(nullstr); retval = 0; argv = argptr; if (!*argv) { /* wait for all jobs */ for (;;) { jp = curjob; while (1) { if (!jp) /* no running procs */ goto ret; if (jp->state == JOBRUNNING) break; jp->waited = 1; jp = jp->prev_job; } /* man bash: * "When bash is waiting for an asynchronous command via * the wait builtin, the reception of a signal for which a trap * has been set will cause the wait builtin to return immediately * with an exit status greater than 128, immediately after which * the trap is executed." */ dowait(DOWAIT_BLOCK_OR_SIG, NULL); /* if child sends us a signal *and immediately exits*, * dowait() returns pid > 0. Check this case, * not "if (dowait() < 0)"! */ if (pending_sig) goto sigout; } } retval = 127; do { if (**argv != '%') { pid_t pid = number(*argv); job = curjob; while (1) { if (!job) goto repeat; if (job->ps[job->nprocs - 1].ps_pid == pid) break; job = job->prev_job; } } else { job = getjob(*argv, 0); } /* loop until process terminated or stopped */ while (job->state == JOBRUNNING) { dowait(DOWAIT_BLOCK_OR_SIG, NULL); if (pending_sig) goto sigout; } job->waited = 1; retval = getstatus(job); repeat: ; } while (*++argv); ret: return retval; sigout: retval = 128 + pending_sig; return retval; } static struct job * growjobtab(void) { size_t len; ptrdiff_t offset; struct job *jp, *jq; len = njobs * sizeof(*jp); jq = jobtab; jp = ckrealloc(jq, len + 4 * sizeof(*jp)); offset = (char *)jp - (char *)jq; if (offset) { /* Relocate pointers */ size_t l = len; jq = (struct job *)((char *)jq + l); while (l) { l -= sizeof(*jp); jq--; #define joff(p) ((struct job *)((char *)(p) + l)) #define jmove(p) (p) = (void *)((char *)(p) + offset) if (joff(jp)->ps == &jq->ps0) jmove(joff(jp)->ps); if (joff(jp)->prev_job) jmove(joff(jp)->prev_job); } if (curjob) jmove(curjob); #undef joff #undef jmove } njobs += 4; jobtab = jp; jp = (struct job *)((char *)jp + len); jq = jp + 3; do { jq->used = 0; } while (--jq >= jp); return jp; } /* * Return a new job structure. * Called with interrupts off. */ static struct job * makejob(/*union node *node,*/ int nprocs) { int i; struct job *jp; for (i = njobs, jp = jobtab; ; jp++) { if (--i < 0) { jp = growjobtab(); break; } if (jp->used == 0) break; if (jp->state != JOBDONE || !jp->waited) continue; #if JOBS if (doing_jobctl) continue; #endif freejob(jp); break; } memset(jp, 0, sizeof(*jp)); #if JOBS /* jp->jobctl is a bitfield. * "jp->jobctl |= doing_jobctl" likely to give awful code */ if (doing_jobctl) jp->jobctl = 1; #endif jp->prev_job = curjob; curjob = jp; jp->used = 1; jp->ps = &jp->ps0; if (nprocs > 1) { jp->ps = ckmalloc(nprocs * sizeof(struct procstat)); } TRACE(("makejob(%d) returns %%%d\n", nprocs, jobno(jp))); return jp; } #if JOBS /* * Return a string identifying a command (to be printed by the * jobs command). */ static char *cmdnextc; static void cmdputs(const char *s) { static const char vstype[VSTYPE + 1][3] = { "", "}", "-", "+", "?", "=", "%", "%%", "#", "##" IF_BASH_SUBSTR(, ":") IF_BASH_PATTERN_SUBST(, "/", "//") }; const char *p, *str; char cc[2]; char *nextc; unsigned char c; unsigned char subtype = 0; int quoted = 0; cc[1] = '\0'; nextc = makestrspace((strlen(s) + 1) * 8, cmdnextc); p = s; while ((c = *p++) != '\0') { str = NULL; switch (c) { case CTLESC: c = *p++; break; case CTLVAR: subtype = *p++; if ((subtype & VSTYPE) == VSLENGTH) str = "${#"; else str = "${"; goto dostr; case CTLENDVAR: str = "\"}" + !(quoted & 1); quoted >>= 1; subtype = 0; goto dostr; case CTLBACKQ: str = "$(...)"; goto dostr; #if ENABLE_FEATURE_SH_MATH case CTLARI: str = "$(("; goto dostr; case CTLENDARI: str = "))"; goto dostr; #endif case CTLQUOTEMARK: quoted ^= 1; c = '"'; break; case '=': if (subtype == 0) break; if ((subtype & VSTYPE) != VSNORMAL) quoted <<= 1; str = vstype[subtype & VSTYPE]; if (subtype & VSNUL) c = ':'; else goto checkstr; break; case '\'': case '\\': case '"': case '$': /* These can only happen inside quotes */ cc[0] = c; str = cc; c = '\\'; break; default: break; } USTPUTC(c, nextc); checkstr: if (!str) continue; dostr: while ((c = *str++) != '\0') { USTPUTC(c, nextc); } } /* while *p++ not NUL */ if (quoted & 1) { USTPUTC('"', nextc); } *nextc = 0; cmdnextc = nextc; } /* cmdtxt() and cmdlist() call each other */ static void cmdtxt(union node *n); static void cmdlist(union node *np, int sep) { for (; np; np = np->narg.next) { if (!sep) cmdputs(" "); cmdtxt(np); if (sep && np->narg.next) cmdputs(" "); } } static void cmdtxt(union node *n) { union node *np; struct nodelist *lp; const char *p; if (!n) return; switch (n->type) { default: #if DEBUG abort(); #endif case NPIPE: lp = n->npipe.cmdlist; for (;;) { cmdtxt(lp->n); lp = lp->next; if (!lp) break; cmdputs(" | "); } break; case NSEMI: p = "; "; goto binop; case NAND: p = " && "; goto binop; case NOR: p = " || "; binop: cmdtxt(n->nbinary.ch1); cmdputs(p); n = n->nbinary.ch2; goto donode; case NREDIR: case NBACKGND: n = n->nredir.n; goto donode; case NNOT: cmdputs("!"); n = n->nnot.com; donode: cmdtxt(n); break; case NIF: cmdputs("if "); cmdtxt(n->nif.test); cmdputs("; then "); if (n->nif.elsepart) { cmdtxt(n->nif.ifpart); cmdputs("; else "); n = n->nif.elsepart; } else { n = n->nif.ifpart; } p = "; fi"; goto dotail; case NSUBSHELL: cmdputs("("); n = n->nredir.n; p = ")"; goto dotail; case NWHILE: p = "while "; goto until; case NUNTIL: p = "until "; until: cmdputs(p); cmdtxt(n->nbinary.ch1); n = n->nbinary.ch2; p = "; done"; dodo: cmdputs("; do "); dotail: cmdtxt(n); goto dotail2; case NFOR: cmdputs("for "); cmdputs(n->nfor.var); cmdputs(" in "); cmdlist(n->nfor.args, 1); n = n->nfor.body; p = "; done"; goto dodo; case NDEFUN: cmdputs(n->narg.text); p = "() { ... }"; goto dotail2; case NCMD: cmdlist(n->ncmd.args, 1); cmdlist(n->ncmd.redirect, 0); break; case NARG: p = n->narg.text; dotail2: cmdputs(p); break; case NHERE: case NXHERE: p = "<<..."; goto dotail2; case NCASE: cmdputs("case "); cmdputs(n->ncase.expr->narg.text); cmdputs(" in "); for (np = n->ncase.cases; np; np = np->nclist.next) { cmdtxt(np->nclist.pattern); cmdputs(") "); cmdtxt(np->nclist.body); cmdputs(";; "); } p = "esac"; goto dotail2; case NTO: p = ">"; goto redir; case NCLOBBER: p = ">|"; goto redir; case NAPPEND: p = ">>"; goto redir; #if BASH_REDIR_OUTPUT case NTO2: #endif case NTOFD: p = ">&"; goto redir; case NFROM: p = "<"; goto redir; case NFROMFD: p = "<&"; goto redir; case NFROMTO: p = "<>"; redir: cmdputs(utoa(n->nfile.fd)); cmdputs(p); if (n->type == NTOFD || n->type == NFROMFD) { cmdputs(utoa(n->ndup.dupfd)); break; } n = n->nfile.fname; goto donode; } } static char * commandtext(union node *n) { char *name; STARTSTACKSTR(cmdnextc); cmdtxt(n); name = stackblock(); TRACE(("commandtext: name %p, end %p\n", name, cmdnextc)); return ckstrdup(name); } #endif /* JOBS */ /* * Fork off a subshell. If we are doing job control, give the subshell its * own process group. Jp is a job structure that the job is to be added to. * N is the command that will be evaluated by the child. Both jp and n may * be NULL. The mode parameter can be one of the following: * FORK_FG - Fork off a foreground process. * FORK_BG - Fork off a background process. * FORK_NOJOB - Like FORK_FG, but don't give the process its own * process group even if job control is on. * * When job control is turned off, background processes have their standard * input redirected to /dev/null (except for the second and later processes * in a pipeline). * * Called with interrupts off. */ /* * Clear traps on a fork. */ static void clear_traps(void) { char **tp; INT_OFF; for (tp = trap; tp < &trap[NSIG]; tp++) { if (*tp && **tp) { /* trap not NULL or "" (SIG_IGN) */ if (trap_ptr == trap) free(*tp); /* else: it "belongs" to trap_ptr vector, don't free */ *tp = NULL; if ((tp - trap) != 0) setsignal(tp - trap); } } may_have_traps = 0; INT_ON; } /* Lives far away from here, needed for forkchild */ static void closescript(void); /* Called after fork(), in child */ /* jp and n are NULL when called by openhere() for heredoc support */ static NOINLINE void forkchild(struct job *jp, union node *n, int mode) { int oldlvl; TRACE(("Child shell %d\n", getpid())); oldlvl = shlvl; shlvl++; /* man bash: "Non-builtin commands run by bash have signal handlers * set to the values inherited by the shell from its parent". * Do we do it correctly? */ closescript(); if (mode == FORK_NOJOB /* is it `xxx` ? */ && n && n->type == NCMD /* is it single cmd? */ /* && n->ncmd.args->type == NARG - always true? */ && n->ncmd.args && strcmp(n->ncmd.args->narg.text, "trap") == 0 && n->ncmd.args->narg.next == NULL /* "trap" with no arguments */ /* && n->ncmd.args->narg.backquote == NULL - do we need to check this? */ ) { TRACE(("Trap hack\n")); /* 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. */ /* Save trap handler strings for trap builtin to print */ trap_ptr = xmemdup(trap, sizeof(trap)); /* Fall through into clearing traps */ } clear_traps(); #if JOBS /* do job control only in root shell */ doing_jobctl = 0; if (mode != FORK_NOJOB && jp->jobctl && oldlvl == 0) { pid_t pgrp; if (jp->nprocs == 0) pgrp = getpid(); else pgrp = jp->ps[0].ps_pid; /* this can fail because we are doing it in the parent also */ setpgid(0, pgrp); if (mode == FORK_FG) xtcsetpgrp(ttyfd, pgrp); setsignal(SIGTSTP); setsignal(SIGTTOU); } else #endif if (mode == FORK_BG) { /* man bash: "When job control is not in effect, * asynchronous commands ignore SIGINT and SIGQUIT" */ ignoresig(SIGINT); ignoresig(SIGQUIT); if (jp->nprocs == 0) { close(0); if (open(bb_dev_null, O_RDONLY) != 0) ash_msg_and_raise_error("can't open '%s'", bb_dev_null); } } if (oldlvl == 0) { if (iflag) { /* why if iflag only? */ setsignal(SIGINT); setsignal(SIGTERM); } /* man bash: * "In all cases, bash ignores SIGQUIT. Non-builtin * commands run by bash have signal handlers * set to the values inherited by the shell * from its parent". * Take care of the second rule: */ setsignal(SIGQUIT); } #if JOBS if (n && n->type == NCMD && n->ncmd.args && strcmp(n->ncmd.args->narg.text, "jobs") == 0 ) { TRACE(("Job hack\n")); /* "jobs": we do not want to clear job list for it, * instead we remove only _its_ own_ job from job list. * This makes "jobs .... | cat" more useful. */ freejob(curjob); return; } #endif for (jp = curjob; jp; jp = jp->prev_job) freejob(jp); jobless = 0; } /* Called after fork(), in parent */ #if !JOBS #define forkparent(jp, n, mode, pid) forkparent(jp, mode, pid) #endif static void forkparent(struct job *jp, union node *n, int mode, pid_t pid) { TRACE(("In parent shell: child = %d\n", pid)); if (!jp) { /* jp is NULL when called by openhere() for heredoc support */ while (jobless && dowait(DOWAIT_NONBLOCK, NULL) > 0) continue; jobless++; return; } #if JOBS if (mode != FORK_NOJOB && jp->jobctl) { int pgrp; if (jp->nprocs == 0) pgrp = pid; else pgrp = jp->ps[0].ps_pid; /* This can fail because we are doing it in the child also */ setpgid(pid, pgrp); } #endif if (mode == FORK_BG) { backgndpid = pid; /* set $! */ set_curjob(jp, CUR_RUNNING); } if (jp) { struct procstat *ps = &jp->ps[jp->nprocs++]; ps->ps_pid = pid; ps->ps_status = -1; ps->ps_cmd = nullstr; #if JOBS if (doing_jobctl && n) ps->ps_cmd = commandtext(n); #endif } } /* jp and n are NULL when called by openhere() for heredoc support */ static int forkshell(struct job *jp, union node *n, int mode) { int pid; TRACE(("forkshell(%%%d, %p, %d) called\n", jobno(jp), n, mode)); pid = fork(); if (pid < 0) { TRACE(("Fork failed, errno=%d", errno)); if (jp) freejob(jp); ash_msg_and_raise_error("can't fork"); } if (pid == 0) { CLEAR_RANDOM_T(&random_gen); /* or else $RANDOM repeats in child */ forkchild(jp, n, mode); } else { forkparent(jp, n, mode, pid); } return pid; } /* * Wait for job to finish. * * Under job control we have the problem that while a child process * is running interrupts generated by the user are sent to the child * but not to the shell. This means that an infinite loop started by * an interactive user may be hard to kill. With job control turned off, * an interactive user may place an interactive program inside a loop. * If the interactive program catches interrupts, the user doesn't want * these interrupts to also abort the loop. The approach we take here * is to have the shell ignore interrupt signals while waiting for a * foreground process to terminate, and then send itself an interrupt * signal if the child process was terminated by an interrupt signal. * Unfortunately, some programs want to do a bit of cleanup and then * exit on interrupt; unless these processes terminate themselves by * sending a signal to themselves (instead of calling exit) they will * confuse this approach. * * Called with interrupts off. */ static int waitforjob(struct job *jp) { int st; TRACE(("waitforjob(%%%d) called\n", jobno(jp))); INT_OFF; while (jp->state == JOBRUNNING) { /* In non-interactive shells, we _can_ get * a keyboard signal here and be EINTRed, * but we just loop back, waiting for command to complete. * * man bash: * "If bash is waiting for a command to complete and receives * a signal for which a trap has been set, the trap * will not be executed until the command completes." * * Reality is that even if trap is not set, bash * will not act on the signal until command completes. * Try this. sleep5intoff.c: * #include * #include * int main() { * sigset_t set; * sigemptyset(&set); * sigaddset(&set, SIGINT); * sigaddset(&set, SIGQUIT); * sigprocmask(SIG_BLOCK, &set, NULL); * sleep(5); * return 0; * } * $ bash -c './sleep5intoff; echo hi' * ^C^C^C^C <--- pressing ^C once a second * $ _ * $ bash -c './sleep5intoff; echo hi' * ^\^\^\^\hi <--- pressing ^\ (SIGQUIT) * $ _ */ dowait(DOWAIT_BLOCK, jp); } INT_ON; st = getstatus(jp); #if JOBS if (jp->jobctl) { xtcsetpgrp(ttyfd, rootpid); restore_tty_if_stopped_or_signaled(jp); /* * This is truly gross. * If we're doing job control, then we did a TIOCSPGRP which * caused us (the shell) to no longer be in the controlling * session -- so we wouldn't have seen any ^C/SIGINT. So, we * intuit from the subprocess exit status whether a SIGINT * occurred, and if so interrupt ourselves. Yuck. - mycroft */ if (jp->sigint) /* TODO: do the same with all signals */ raise(SIGINT); /* ... by raise(jp->sig) instead? */ } if (jp->state == JOBDONE) #endif freejob(jp); return st; } /* * return 1 if there are stopped jobs, otherwise 0 */ static int stoppedjobs(void) { struct job *jp; int retval; retval = 0; if (job_warning) goto out; jp = curjob; if (jp && jp->state == JOBSTOPPED) { out2str("You have stopped jobs.\n"); job_warning = 2; retval++; } out: return retval; } /* * Code for dealing with input/output redirection. */ #undef EMPTY #undef CLOSED #define EMPTY -2 /* marks an unused slot in redirtab */ #define CLOSED -3 /* marks a slot of previously-closed fd */ /* * Open a file in noclobber mode. * The code was copied from bash. */ static int noclobberopen(const char *fname) { int r, fd; struct stat finfo, finfo2; /* * If the file exists and is a regular file, return an error * immediately. */ r = stat(fname, &finfo); if (r == 0 && S_ISREG(finfo.st_mode)) { errno = EEXIST; return -1; } /* * If the file was not present (r != 0), make sure we open it * exclusively so that if it is created before we open it, our open * will fail. Make sure that we do not truncate an existing file. * Note that we don't turn on O_EXCL unless the stat failed -- if the * file was not a regular file, we leave O_EXCL off. */ if (r != 0) return open(fname, O_WRONLY|O_CREAT|O_EXCL, 0666); fd = open(fname, O_WRONLY|O_CREAT, 0666); /* If the open failed, return the file descriptor right away. */ if (fd < 0) return fd; /* * OK, the open succeeded, but the file may have been changed from a * non-regular file to a regular file between the stat and the open. * We are assuming that the O_EXCL open handles the case where FILENAME * did not exist and is symlinked to an existing file between the stat * and open. */ /* * If we can open it and fstat the file descriptor, and neither check * revealed that it was a regular file, and the file has not been * replaced, return the file descriptor. */ if (fstat(fd, &finfo2) == 0 && !S_ISREG(finfo2.st_mode) && finfo.st_dev == finfo2.st_dev && finfo.st_ino == finfo2.st_ino ) { return fd; } /* The file has been replaced. badness. */ close(fd); errno = EEXIST; return -1; } /* * Handle here documents. Normally we fork off a process to write the * data to a pipe. If the document is short, we can stuff the data in * the pipe without forking. */ /* openhere needs this forward reference */ static void expandhere(union node *arg, int fd); static int openhere(union node *redir) { int pip[2]; size_t len = 0; if (pipe(pip) < 0) ash_msg_and_raise_error("pipe call failed"); if (redir->type == NHERE) { len = strlen(redir->nhere.doc->narg.text); if (len <= PIPE_BUF) { full_write(pip[1], redir->nhere.doc->narg.text, len); goto out; } } if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) { /* child */ close(pip[0]); ignoresig(SIGINT); //signal(SIGINT, SIG_IGN); ignoresig(SIGQUIT); //signal(SIGQUIT, SIG_IGN); ignoresig(SIGHUP); //signal(SIGHUP, SIG_IGN); ignoresig(SIGTSTP); //signal(SIGTSTP, SIG_IGN); signal(SIGPIPE, SIG_DFL); if (redir->type == NHERE) full_write(pip[1], redir->nhere.doc->narg.text, len); else /* NXHERE */ expandhere(redir->nhere.doc, pip[1]); _exit(EXIT_SUCCESS); } out: close(pip[1]); return pip[0]; } static int openredirect(union node *redir) { char *fname; int f; switch (redir->nfile.type) { /* Can't happen, our single caller does this itself */ // case NTOFD: // case NFROMFD: // return -1; case NHERE: case NXHERE: return openhere(redir); } /* For N[X]HERE, reading redir->nfile.expfname would touch beyond * allocated space. Do it only when we know it is safe. */ fname = redir->nfile.expfname; switch (redir->nfile.type) { default: #if DEBUG abort(); #endif case NFROM: f = open(fname, O_RDONLY); if (f < 0) goto eopen; break; case NFROMTO: f = open(fname, O_RDWR|O_CREAT, 0666); if (f < 0) goto ecreate; break; case NTO: #if BASH_REDIR_OUTPUT case NTO2: #endif /* Take care of noclobber mode. */ if (Cflag) { f = noclobberopen(fname); if (f < 0) goto ecreate; break; } /* FALLTHROUGH */ case NCLOBBER: f = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666); if (f < 0) goto ecreate; break; case NAPPEND: f = open(fname, O_WRONLY|O_CREAT|O_APPEND, 0666); if (f < 0) goto ecreate; break; } return f; ecreate: ash_msg_and_raise_error("can't create %s: %s", fname, errmsg(errno, "nonexistent directory")); eopen: ash_msg_and_raise_error("can't open %s: %s", fname, errmsg(errno, "no such file")); } /* * Copy a file descriptor to be >= 10. Throws exception on error. */ static int savefd(int from) { int newfd; int err; newfd = fcntl(from, F_DUPFD, 10); err = newfd < 0 ? errno : 0; if (err != EBADF) { if (err) ash_msg_and_raise_error("%d: %m", from); close(from); fcntl(newfd, F_SETFD, FD_CLOEXEC); } return newfd; } static int dup2_or_raise(int from, int to) { int newfd; newfd = (from != to) ? dup2(from, to) : to; if (newfd < 0) { /* Happens when source fd is not open: try "echo >&99" */ ash_msg_and_raise_error("%d: %m", from); } return newfd; } /* Struct def and variable are moved down to the first usage site */ struct two_fd_t { int orig, copy; }; struct redirtab { struct redirtab *next; int pair_count; struct two_fd_t two_fd[]; }; #define redirlist (G_var.redirlist) enum { COPYFD_RESTORE = (int)~(INT_MAX), }; static int need_to_remember(struct redirtab *rp, int fd) { int i; if (!rp) /* remembering was not requested */ return 0; for (i = 0; i < rp->pair_count; i++) { if (rp->two_fd[i].orig == fd) { /* already remembered */ return 0; } } return 1; } /* "hidden" fd is a fd used to read scripts, or a copy of such */ static int is_hidden_fd(struct redirtab *rp, int fd) { int i; struct parsefile *pf; if (fd == -1) return 0; /* Check open scripts' fds */ pf = g_parsefile; while (pf) { /* We skip pf_fd == 0 case because of the following case: * $ ash # running ash interactively * $ . ./script.sh * and in script.sh: "exec 9>&0". * Even though top-level pf_fd _is_ 0, * it's still ok to use it: "read" builtin uses it, * why should we cripple "exec" builtin? */ if (pf->pf_fd > 0 && fd == pf->pf_fd) { return 1; } pf = pf->prev; } if (!rp) return 0; /* Check saved fds of redirects */ fd |= COPYFD_RESTORE; for (i = 0; i < rp->pair_count; i++) { if (rp->two_fd[i].copy == fd) { return 1; } } return 0; } /* * Process a list of redirection commands. If the REDIR_PUSH flag is set, * old file descriptors are stashed away so that the redirection can be * undone by calling popredir. */ /* flags passed to redirect */ #define REDIR_PUSH 01 /* save previous values of file descriptors */ #define REDIR_SAVEFD2 03 /* set preverrout */ static void redirect(union node *redir, int flags) { struct redirtab *sv; int sv_pos; int i; int fd; int newfd; int copied_fd2 = -1; if (!redir) { return; } sv = NULL; sv_pos = 0; INT_OFF; if (flags & REDIR_PUSH) { union node *tmp = redir; do { sv_pos++; #if BASH_REDIR_OUTPUT if (tmp->nfile.type == NTO2) sv_pos++; #endif tmp = tmp->nfile.next; } while (tmp); sv = ckmalloc(sizeof(*sv) + sv_pos * sizeof(sv->two_fd[0])); sv->next = redirlist; sv->pair_count = sv_pos; redirlist = sv; while (sv_pos > 0) { sv_pos--; sv->two_fd[sv_pos].orig = sv->two_fd[sv_pos].copy = EMPTY; } } do { int right_fd = -1; fd = redir->nfile.fd; if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) { right_fd = redir->ndup.dupfd; //bb_error_msg("doing %d > %d", fd, right_fd); /* redirect from/to same file descriptor? */ if (right_fd == fd) continue; /* "echo >&10" and 10 is a fd opened to a sh script? */ if (is_hidden_fd(sv, right_fd)) { errno = EBADF; /* as if it is closed */ ash_msg_and_raise_error("%d: %m", right_fd); } newfd = -1; } else { newfd = openredirect(redir); /* always >= 0 */ if (fd == newfd) { /* Descriptor wasn't open before redirect. * Mark it for close in the future */ if (need_to_remember(sv, fd)) { goto remember_to_close; } continue; } } #if BASH_REDIR_OUTPUT redirect_more: #endif if (need_to_remember(sv, fd)) { /* Copy old descriptor */ /* Careful to not accidentally "save" * to the same fd as right side fd in N>&M */ int minfd = right_fd < 10 ? 10 : right_fd + 1; #if defined(F_DUPFD_CLOEXEC) i = fcntl(fd, F_DUPFD_CLOEXEC, minfd); #else i = fcntl(fd, F_DUPFD, minfd); #endif if (i == -1) { i = errno; if (i != EBADF) { /* Strange error (e.g. "too many files" EMFILE?) */ if (newfd >= 0) close(newfd); errno = i; ash_msg_and_raise_error("%d: %m", fd); /* NOTREACHED */ } /* EBADF: it is not open - good, remember to close it */ remember_to_close: i = CLOSED; } else { /* fd is open, save its copy */ #if !defined(F_DUPFD_CLOEXEC) fcntl(i, F_SETFD, FD_CLOEXEC); #endif /* "exec fd>&-" should not close fds * which point to script file(s). * Force them to be restored afterwards */ if (is_hidden_fd(sv, fd)) i |= COPYFD_RESTORE; } if (fd == 2) copied_fd2 = i; sv->two_fd[sv_pos].orig = fd; sv->two_fd[sv_pos].copy = i; sv_pos++; } if (newfd < 0) { /* NTOFD/NFROMFD: copy redir->ndup.dupfd to fd */ if (redir->ndup.dupfd < 0) { /* "fd>&-" */ /* Don't want to trigger debugging */ if (fd != -1) close(fd); } else { dup2_or_raise(redir->ndup.dupfd, fd); } } else if (fd != newfd) { /* move newfd to fd */ dup2_or_raise(newfd, fd); #if BASH_REDIR_OUTPUT if (!(redir->nfile.type == NTO2 && fd == 2)) #endif close(newfd); } #if BASH_REDIR_OUTPUT if (redir->nfile.type == NTO2 && fd == 1) { /* We already redirected it to fd 1, now copy it to 2 */ newfd = 1; fd = 2; goto redirect_more; } #endif } while ((redir = redir->nfile.next) != NULL); INT_ON; if ((flags & REDIR_SAVEFD2) && copied_fd2 >= 0) preverrout_fd = copied_fd2; } /* * Undo the effects of the last redirection. */ static void popredir(int drop, int restore) { struct redirtab *rp; int i; if (redirlist == NULL) return; INT_OFF; rp = redirlist; for (i = 0; i < rp->pair_count; i++) { int fd = rp->two_fd[i].orig; int copy = rp->two_fd[i].copy; if (copy == CLOSED) { if (!drop) close(fd); continue; } if (copy != EMPTY) { if (!drop || (restore && (copy & COPYFD_RESTORE))) { copy &= ~COPYFD_RESTORE; /*close(fd);*/ dup2_or_raise(copy, fd); } close(copy & ~COPYFD_RESTORE); } } redirlist = rp->next; free(rp); INT_ON; } /* * Undo all redirections. Called on error or interrupt. */ static int redirectsafe(union node *redir, int flags) { int err; volatile int saveint; struct jmploc *volatile savehandler = exception_handler; struct jmploc jmploc; SAVE_INT(saveint); /* "echo 9>/dev/null; echo >&9; echo result: $?" - result should be 1, not 2! */ err = setjmp(jmploc.loc); // huh?? was = setjmp(jmploc.loc) * 2; if (!err) { exception_handler = &jmploc; redirect(redir, flags); } exception_handler = savehandler; if (err && exception_type != EXERROR) longjmp(exception_handler->loc, 1); RESTORE_INT(saveint); return err; } /* ============ Routines to expand arguments to commands * * We have to deal with backquotes, shell variables, and file metacharacters. */ #if ENABLE_FEATURE_SH_MATH static arith_t ash_arith(const char *s) { arith_state_t math_state; arith_t result; math_state.lookupvar = lookupvar; math_state.setvar = setvar0; //math_state.endofname = endofname; INT_OFF; result = arith(&math_state, s); if (math_state.errmsg) ash_msg_and_raise_error(math_state.errmsg); INT_ON; return result; } #endif /* * expandarg flags */ #define EXP_FULL 0x1 /* perform word splitting & file globbing */ #define EXP_TILDE 0x2 /* do normal tilde expansion */ #define EXP_VARTILDE 0x4 /* expand tildes in an assignment */ #define EXP_REDIR 0x8 /* file glob for a redirection (1 match only) */ /* ^^^^^^^^^^^^^^ this is meant to support constructs such as "cmd >file*.txt" * POSIX says for this case: * 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. * Currently, our code complies to the above rule by never globbing * redirection filenames. * Bash performs globbing, unless it is non-interactive and in POSIX mode. * (this means that on a typical Linux distro, bash almost always * performs globbing, and thus diverges from what we do). */ #define EXP_CASE 0x10 /* keeps quotes around for CASE pattern */ #define EXP_QPAT 0x20 /* pattern in quoted parameter expansion */ #define EXP_VARTILDE2 0x40 /* expand tildes after colons only */ #define EXP_WORD 0x80 /* expand word in parameter expansion */ #define EXP_QUOTED 0x100 /* expand word in double quotes */ /* * rmescape() flags */ #define RMESCAPE_ALLOC 0x1 /* Allocate a new string */ #define RMESCAPE_GLOB 0x2 /* Add backslashes for glob */ #define RMESCAPE_GROW 0x8 /* Grow strings instead of stalloc */ #define RMESCAPE_HEAP 0x10 /* Malloc strings instead of stalloc */ #define RMESCAPE_SLASH 0x20 /* Stop globbing after slash */ /* Add CTLESC when necessary. */ #define QUOTES_ESC (EXP_FULL | EXP_CASE | EXP_QPAT | EXP_REDIR) /* Do not skip NUL characters. */ #define QUOTES_KEEPNUL EXP_TILDE /* * Structure specifying which parts of the string should be searched * for IFS characters. */ struct ifsregion { struct ifsregion *next; /* next region in list */ int begoff; /* offset of start of region */ int endoff; /* offset of end of region */ int nulonly; /* search for nul bytes only */ }; struct arglist { struct strlist *list; struct strlist **lastp; }; /* output of current string */ static char *expdest; /* list of back quote expressions */ static struct nodelist *argbackq; /* first struct in list of ifs regions */ static struct ifsregion ifsfirst; /* last struct in list */ static struct ifsregion *ifslastp; /* holds expanded arg list */ static struct arglist exparg; /* * Our own itoa(). */ #if !ENABLE_FEATURE_SH_MATH /* cvtnum() is used even if math support is off (to prepare $? values and such) */ typedef long arith_t; # define ARITH_FMT "%ld" #endif static int cvtnum(arith_t num) { int len; expdest = makestrspace(sizeof(arith_t)*3 + 2, expdest); len = fmtstr(expdest, sizeof(arith_t)*3 + 2, ARITH_FMT, num); STADJUST(len, expdest); return len; } /* * Break the argument string into pieces based upon IFS and add the * strings to the argument list. The regions of the string to be * searched for IFS characters have been stored by recordregion. */ static void ifsbreakup(char *string, struct arglist *arglist) { struct ifsregion *ifsp; struct strlist *sp; char *start; char *p; char *q; const char *ifs, *realifs; int ifsspc; int nulonly; start = string; if (ifslastp != NULL) { ifsspc = 0; nulonly = 0; realifs = ifsset() ? ifsval() : defifs; ifsp = &ifsfirst; do { p = string + ifsp->begoff; nulonly = ifsp->nulonly; ifs = nulonly ? nullstr : realifs; ifsspc = 0; while (p < string + ifsp->endoff) { q = p; if ((unsigned char)*p == CTLESC) p++; if (!strchr(ifs, *p)) { p++; continue; } if (!nulonly) ifsspc = (strchr(defifs, *p) != NULL); /* Ignore IFS whitespace at start */ if (q == start && ifsspc) { p++; start = p; continue; } *q = '\0'; sp = stzalloc(sizeof(*sp)); sp->text = start; *arglist->lastp = sp; arglist->lastp = &sp->next; p++; if (!nulonly) { for (;;) { if (p >= string + ifsp->endoff) { break; } q = p; if ((unsigned char)*p == CTLESC) p++; if (strchr(ifs, *p) == NULL) { p = q; break; } if (strchr(defifs, *p) == NULL) { if (ifsspc) { p++; ifsspc = 0; } else { p = q; break; } } else p++; } } start = p; } /* while */ ifsp = ifsp->next; } while (ifsp != NULL); if (nulonly) goto add; } if (!*start) return; add: sp = stzalloc(sizeof(*sp)); sp->text = start; *arglist->lastp = sp; arglist->lastp = &sp->next; } static void ifsfree(void) { struct ifsregion *p = ifsfirst.next; if (!p) goto out; INT_OFF; do { struct ifsregion *ifsp; ifsp = p->next; free(p); p = ifsp; } while (p); ifsfirst.next = NULL; INT_ON; out: ifslastp = NULL; } static size_t esclen(const char *start, const char *p) { size_t esc = 0; while (p > start && (unsigned char)*--p == CTLESC) { esc++; } return esc; } /* * Remove any CTLESC characters from a string. */ static char * rmescapes(char *str, int flag) { static const char qchars[] ALIGN1 = { IF_BASH_PATTERN_SUBST('/',) CTLESC, CTLQUOTEMARK, '\0' }; char *p, *q, *r; unsigned inquotes; unsigned protect_against_glob; unsigned globbing; IF_BASH_PATTERN_SUBST(unsigned slash = flag & RMESCAPE_SLASH;) p = strpbrk(str, qchars IF_BASH_PATTERN_SUBST(+ !slash)); if (!p) return str; q = p; r = str; if (flag & RMESCAPE_ALLOC) { size_t len = p - str; size_t fulllen = len + strlen(p) + 1; if (flag & RMESCAPE_GROW) { int strloc = str - (char *)stackblock(); r = makestrspace(fulllen, expdest); /* p and str may be invalidated by makestrspace */ str = (char *)stackblock() + strloc; p = str + len; } else if (flag & RMESCAPE_HEAP) { r = ckmalloc(fulllen); } else { r = stalloc(fulllen); } q = r; if (len > 0) { q = (char *)memcpy(q, str, len) + len; } } inquotes = 0; globbing = flag & RMESCAPE_GLOB; protect_against_glob = globbing; while (*p) { if ((unsigned char)*p == CTLQUOTEMARK) { // Note: both inquotes and protect_against_glob only affect whether // CTLESC, gets converted to or to \ inquotes = ~inquotes; p++; protect_against_glob = globbing; continue; } if ((unsigned char)*p == CTLESC) { p++; #if DEBUG if (*p == '\0') ash_msg_and_raise_error("CTLESC at EOL (shouldn't happen)"); #endif if (protect_against_glob) { /* * We used to trust glob() and fnmatch() to eat * superfluous escapes (\z where z has no * special meaning anyway). But this causes * bugs such as string of one greek letter rho * (unicode-encoded as two bytes "cf,81") * getting encoded as "cf,CTLESC,81" * and here, converted to "cf,\,81" - * which does not go well with some flavors * of fnmatch() in unicode locales * (for example, glibc <= 2.22). * * Lets add "\" only on the chars which need it. */ if (*p == '*' || *p == '?' || *p == '[' /* || *p == ']' maybe also this? */ || *p == '\\' ) { *q++ = '\\'; } } } else if (*p == '\\' && !inquotes) { /* naked back slash */ protect_against_glob = 0; goto copy; } #if BASH_PATTERN_SUBST else if (*p == '/' && slash) { /* stop handling globbing and mark location of slash */ globbing = slash = 0; *p = CTLESC; } #endif protect_against_glob = globbing; copy: *q++ = *p++; } *q = '\0'; if (flag & RMESCAPE_GROW) { expdest = r; STADJUST(q - r + 1, expdest); } return r; } #define pmatch(a, b) !fnmatch((a), (b), 0) /* * Prepare a pattern for a expmeta (internal glob(3)) call. * * Returns an stalloced string. */ static char * preglob(const char *pattern, int flag) { return rmescapes((char *)pattern, flag | RMESCAPE_GLOB); } /* * Put a string on the stack. */ static void memtodest(const char *p, size_t len, int syntax, int quotes) { char *q; if (!len) return; q = makestrspace((quotes & QUOTES_ESC) ? len * 2 : len, expdest); do { unsigned char c = *p++; if (c) { if (quotes & QUOTES_ESC) { int n = SIT(c, syntax); if (n == CCTL || (((quotes & EXP_FULL) || syntax != BASESYNTAX) && n == CBACK ) ) { USTPUTC(CTLESC, q); } } } else if (!(quotes & QUOTES_KEEPNUL)) continue; USTPUTC(c, q); } while (--len); expdest = q; } static size_t strtodest(const char *p, int syntax, int quotes) { size_t len = strlen(p); memtodest(p, len, syntax, quotes); return len; } /* * Record the fact that we have to scan this region of the * string for IFS characters. */ static void recordregion(int start, int end, int nulonly) { struct ifsregion *ifsp; if (ifslastp == NULL) { ifsp = &ifsfirst; } else { INT_OFF; ifsp = ckzalloc(sizeof(*ifsp)); /*ifsp->next = NULL; - ckzalloc did it */ ifslastp->next = ifsp; INT_ON; } ifslastp = ifsp; ifslastp->begoff = start; ifslastp->endoff = end; ifslastp->nulonly = nulonly; } static void removerecordregions(int endoff) { if (ifslastp == NULL) return; if (ifsfirst.endoff > endoff) { while (ifsfirst.next) { struct ifsregion *ifsp; INT_OFF; ifsp = ifsfirst.next->next; free(ifsfirst.next); ifsfirst.next = ifsp; INT_ON; } if (ifsfirst.begoff > endoff) { ifslastp = NULL; } else { ifslastp = &ifsfirst; ifsfirst.endoff = endoff; } return; } ifslastp = &ifsfirst; while (ifslastp->next && ifslastp->next->begoff < endoff) ifslastp = ifslastp->next; while (ifslastp->next) { struct ifsregion *ifsp; INT_OFF; ifsp = ifslastp->next->next; free(ifslastp->next); ifslastp->next = ifsp; INT_ON; } if (ifslastp->endoff > endoff) ifslastp->endoff = endoff; } static char * exptilde(char *startp, char *p, int flags) { unsigned char c; char *name; struct passwd *pw; const char *home; int quotes = flags & QUOTES_ESC; name = p + 1; while ((c = *++p) != '\0') { switch (c) { case CTLESC: return startp; case CTLQUOTEMARK: return startp; case ':': if (flags & EXP_VARTILDE) goto done; break; case '/': case CTLENDVAR: goto done; } } done: *p = '\0'; if (*name == '\0') { home = lookupvar("HOME"); } else { pw = getpwnam(name); if (pw == NULL) goto lose; home = pw->pw_dir; } if (!home || !*home) goto lose; *p = c; strtodest(home, SQSYNTAX, quotes); return p; lose: *p = c; return startp; } /* * Execute a command inside back quotes. If it's a builtin command, we * want to save its output in a block obtained from malloc. Otherwise * we fork off a subprocess and get the output of the command via a pipe. * Should be called with interrupts off. */ struct backcmd { /* result of evalbackcmd */ int fd; /* file descriptor to read from */ int nleft; /* number of chars in buffer */ char *buf; /* buffer */ struct job *jp; /* job structure for command */ }; /* These forward decls are needed to use "eval" code for backticks handling: */ #define EV_EXIT 01 /* exit after evaluating tree */ static int evaltree(union node *, int); static void FAST_FUNC evalbackcmd(union node *n, struct backcmd *result) { int pip[2]; struct job *jp; result->fd = -1; result->buf = NULL; result->nleft = 0; result->jp = NULL; if (n == NULL) { goto out; } if (pipe(pip) < 0) ash_msg_and_raise_error("pipe call failed"); jp = makejob(/*n,*/ 1); if (forkshell(jp, n, FORK_NOJOB) == 0) { /* child */ FORCE_INT_ON; close(pip[0]); if (pip[1] != 1) { /*close(1);*/ dup2_or_raise(pip[1], 1); close(pip[1]); } /* TODO: eflag clearing makes the following not abort: * ash -c 'set -e; z=$(false;echo foo); echo $z' * which is what bash does (unless it is in POSIX mode). * dash deleted "eflag = 0" line in the commit * Date: Mon, 28 Jun 2010 17:11:58 +1000 * [EVAL] Don't clear eflag in evalbackcmd * For now, preserve bash-like behavior, it seems to be somewhat more useful: */ eflag = 0; ifsfree(); evaltree(n, EV_EXIT); /* actually evaltreenr... */ /* NOTREACHED */ } /* parent */ close(pip[1]); result->fd = pip[0]; result->jp = jp; out: TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n", result->fd, result->buf, result->nleft, result->jp)); } /* * Expand stuff in backwards quotes. */ static void expbackq(union node *cmd, int flag) { struct backcmd in; int i; char buf[128]; char *p; char *dest; int startloc; int syntax = flag & EXP_QUOTED ? DQSYNTAX : BASESYNTAX; struct stackmark smark; INT_OFF; startloc = expdest - (char *)stackblock(); pushstackmark(&smark, startloc); evalbackcmd(cmd, &in); popstackmark(&smark); p = in.buf; i = in.nleft; if (i == 0) goto read; for (;;) { memtodest(p, i, syntax, flag & QUOTES_ESC); read: if (in.fd < 0) break; i = nonblock_immune_read(in.fd, buf, sizeof(buf)); TRACE(("expbackq: read returns %d\n", i)); if (i <= 0) break; p = buf; } free(in.buf); if (in.fd >= 0) { close(in.fd); back_exitstatus = waitforjob(in.jp); } INT_ON; /* Eat all trailing newlines */ dest = expdest; for (; dest > (char *)stackblock() && dest[-1] == '\n';) STUNPUTC(dest); expdest = dest; if (!(flag & EXP_QUOTED)) recordregion(startloc, dest - (char *)stackblock(), 0); TRACE(("evalbackq: size:%d:'%.*s'\n", (int)((dest - (char *)stackblock()) - startloc), (int)((dest - (char *)stackblock()) - startloc), stackblock() + startloc)); } #if ENABLE_FEATURE_SH_MATH /* * Expand arithmetic expression. Backup to start of expression, * evaluate, place result in (backed up) result, adjust string position. */ static void expari(int flag) { char *p, *start; int begoff; int len; /* ifsfree(); */ /* * This routine is slightly over-complicated for * efficiency. Next we scan backwards looking for the * start of arithmetic. */ start = stackblock(); p = expdest - 1; *p = '\0'; p--; while (1) { int esc; while ((unsigned char)*p != CTLARI) { p--; #if DEBUG if (p < start) { ash_msg_and_raise_error("missing CTLARI (shouldn't happen)"); } #endif } esc = esclen(start, p); if (!(esc % 2)) { break; } p -= esc + 1; } begoff = p - start; removerecordregions(begoff); expdest = p; if (flag & QUOTES_ESC) rmescapes(p + 1, 0); len = cvtnum(ash_arith(p + 1)); if (!(flag & EXP_QUOTED)) recordregion(begoff, begoff + len, 0); } #endif /* argstr needs it */ static char *evalvar(char *p, int flags, struct strlist *var_str_list); /* * Perform variable and command substitution. If EXP_FULL is set, output CTLESC * characters to allow for further processing. Otherwise treat * $@ like $* since no splitting will be performed. * * var_str_list (can be NULL) is a list of "VAR=val" strings which take precedence * over shell variables. Needed for "A=a B=$A; echo $B" case - we use it * for correct expansion of "B=$A" word. */ static void argstr(char *p, int flags, struct strlist *var_str_list) { static const char spclchars[] ALIGN1 = { '=', ':', CTLQUOTEMARK, CTLENDVAR, CTLESC, CTLVAR, CTLBACKQ, #if ENABLE_FEATURE_SH_MATH CTLENDARI, #endif '\0' }; const char *reject = spclchars; int breakall = (flags & (EXP_WORD | EXP_QUOTED)) == EXP_WORD; int inquotes; size_t length; int startloc; if (!(flags & EXP_VARTILDE)) { reject += 2; } else if (flags & EXP_VARTILDE2) { reject++; } inquotes = 0; length = 0; if (flags & EXP_TILDE) { char *q; flags &= ~EXP_TILDE; tilde: q = p; if (*q == '~') p = exptilde(p, q, flags); } start: startloc = expdest - (char *)stackblock(); for (;;) { unsigned char c; length += strcspn(p + length, reject); c = p[length]; if (c) { if (!(c & 0x80) IF_FEATURE_SH_MATH(|| c == CTLENDARI) ) { /* c == '=' || c == ':' || c == CTLENDARI */ length++; } } if (length > 0) { int newloc; expdest = stack_nputstr(p, length, expdest); newloc = expdest - (char *)stackblock(); if (breakall && !inquotes && newloc > startloc) { recordregion(startloc, newloc, 0); } startloc = newloc; } p += length + 1; length = 0; switch (c) { case '\0': goto breakloop; case '=': if (flags & EXP_VARTILDE2) { p--; continue; } flags |= EXP_VARTILDE2; reject++; /* fall through */ case ':': /* * sort of a hack - expand tildes in variable * assignments (after the first '=' and after ':'s). */ if (*--p == '~') { goto tilde; } continue; } switch (c) { case CTLENDVAR: /* ??? */ goto breakloop; case CTLQUOTEMARK: inquotes ^= EXP_QUOTED; /* "$@" syntax adherence hack */ if (inquotes && !memcmp(p, dolatstr + 1, DOLATSTRLEN - 1)) { p = evalvar(p + 1, flags | inquotes, /* var_str_list: */ NULL) + 1; goto start; } addquote: if (flags & QUOTES_ESC) { p--; length++; startloc++; } break; case CTLESC: startloc++; length++; /* * Quoted parameter expansion pattern: remove quote * unless inside inner quotes or we have a literal * backslash. */ if (((flags | inquotes) & (EXP_QPAT | EXP_QUOTED)) == EXP_QPAT && *p != '\\') break; goto addquote; case CTLVAR: TRACE(("argstr: evalvar('%s')\n", p)); p = evalvar(p, flags | inquotes, var_str_list); TRACE(("argstr: evalvar:'%s'\n", (char *)stackblock())); goto start; case CTLBACKQ: expbackq(argbackq->n, flags | inquotes); argbackq = argbackq->next; goto start; #if ENABLE_FEATURE_SH_MATH case CTLENDARI: p--; expari(flags | inquotes); goto start; #endif } } breakloop: ; } static char * scanleft(char *startp, char *rmesc, char *rmescend UNUSED_PARAM, char *pattern, int quotes, int zero) { char *loc, *loc2; char c; loc = startp; loc2 = rmesc; do { int match; const char *s = loc2; c = *loc2; if (zero) { *loc2 = '\0'; s = rmesc; } match = pmatch(pattern, s); *loc2 = c; if (match) return loc; if (quotes && (unsigned char)*loc == CTLESC) loc++; loc++; loc2++; } while (c); return NULL; } static char * scanright(char *startp, char *rmesc, char *rmescend, char *pattern, int quotes, int match_at_start) { #if !ENABLE_ASH_OPTIMIZE_FOR_SIZE int try2optimize = match_at_start; #endif int esc = 0; char *loc; char *loc2; /* If we called by "${v/pattern/repl}" or "${v//pattern/repl}": * startp="escaped_value_of_v" rmesc="raw_value_of_v" * rmescend=""(ptr to NUL in rmesc) pattern="pattern" quotes=match_at_start=1 * Logic: * loc starts at NUL at the end of startp, loc2 starts at the end of rmesc, * and on each iteration they go back two/one char until they reach the beginning. * We try to find a match in "raw_value_of_v", "raw_value_of_", "raw_value_of" etc. */ /* TODO: document in what other circumstances we are called. */ for (loc = pattern - 1, loc2 = rmescend; loc >= startp; loc2--) { int match; char c = *loc2; const char *s = loc2; if (match_at_start) { *loc2 = '\0'; s = rmesc; } match = pmatch(pattern, s); //bb_error_msg("pmatch(pattern:'%s',s:'%s'):%d", pattern, s, match); *loc2 = c; if (match) return loc; #if !ENABLE_ASH_OPTIMIZE_FOR_SIZE if (try2optimize) { /* Maybe we can optimize this: * if pattern ends with unescaped *, we can avoid checking * shorter strings: if "foo*" doesn't match "raw_value_of_v", * it won't match truncated "raw_value_of_" strings too. */ unsigned plen = strlen(pattern); /* Does it end with "*"? */ if (plen != 0 && pattern[--plen] == '*') { /* "xxxx*" is not escaped */ /* "xxx\*" is escaped */ /* "xx\\*" is not escaped */ /* "x\\\*" is escaped */ int slashes = 0; while (plen != 0 && pattern[--plen] == '\\') slashes++; if (!(slashes & 1)) break; /* ends with unescaped "*" */ } try2optimize = 0; } #endif loc--; if (quotes) { if (--esc < 0) { esc = esclen(startp, loc); } if (esc % 2) { esc--; loc--; } } } return NULL; } static void varunset(const char *, const char *, const char *, int) NORETURN; static void varunset(const char *end, const char *var, const char *umsg, int varflags) { const char *msg; const char *tail; tail = nullstr; msg = "parameter not set"; if (umsg) { if ((unsigned char)*end == CTLENDVAR) { if (varflags & VSNUL) tail = " or null"; } else { msg = umsg; } } ash_msg_and_raise_error("%.*s: %s%s", (int)(end - var - 1), var, msg, tail); } static const char * subevalvar(char *p, char *varname, int strloc, int subtype, int startloc, int varflags, int flag, struct strlist *var_str_list) { struct nodelist *saveargbackq = argbackq; int quotes = flag & QUOTES_ESC; char *startp; char *loc; char *rmesc, *rmescend; char *str; IF_BASH_SUBSTR(int pos, len, orig_len;) int amount, resetloc; IF_BASH_PATTERN_SUBST(int workloc;) IF_BASH_PATTERN_SUBST(char *repl = NULL;) int zero; char *(*scan)(char*, char*, char*, char*, int, int); //bb_error_msg("subevalvar(p:'%s',varname:'%s',strloc:%d,subtype:%d,startloc:%d,varflags:%x,quotes:%d)", // p, varname, strloc, subtype, startloc, varflags, quotes); argstr(p, EXP_TILDE | (subtype != VSASSIGN && subtype != VSQUESTION ? (flag & (EXP_QUOTED | EXP_QPAT) ? EXP_QPAT : EXP_CASE) : 0), var_str_list); STPUTC('\0', expdest); argbackq = saveargbackq; startp = (char *)stackblock() + startloc; switch (subtype) { case VSASSIGN: setvar0(varname, startp); amount = startp - expdest; STADJUST(amount, expdest); return startp; case VSQUESTION: varunset(p, varname, startp, varflags); /* NOTREACHED */ #if BASH_SUBSTR case VSSUBSTR: //TODO: support more general format ${v:EXPR:EXPR}, // where EXPR follows $(()) rules loc = str = stackblock() + strloc; /* Read POS in ${var:POS:LEN} */ pos = atoi(loc); /* number(loc) errors out on "1:4" */ len = str - startp - 1; /* *loc != '\0', guaranteed by parser */ if (quotes) { char *ptr; /* Adjust the length by the number of escapes */ for (ptr = startp; ptr < (str - 1); ptr++) { if ((unsigned char)*ptr == CTLESC) { len--; ptr++; } } } orig_len = len; if (*loc++ == ':') { /* ${var::LEN} */ len = number(loc); } else { /* Skip POS in ${var:POS:LEN} */ len = orig_len; while (*loc && *loc != ':') { /* TODO? * bash complains on: var=qwe; echo ${var:1a:123} if (!isdigit(*loc)) ash_msg_and_raise_error(msg_illnum, str); */ loc++; } if (*loc++ == ':') { len = number(loc); } } if (pos < 0) { /* ${VAR:$((-n)):l} starts n chars from the end */ pos = orig_len + pos; } if ((unsigned)pos >= orig_len) { /* apart from obvious ${VAR:999999:l}, * covers ${VAR:$((-9999999)):l} - result is "" * (bash-compat) */ pos = 0; len = 0; } if (len > (orig_len - pos)) len = orig_len - pos; for (str = startp; pos; str++, pos--) { if (quotes && (unsigned char)*str == CTLESC) str++; } for (loc = startp; len; len--) { if (quotes && (unsigned char)*str == CTLESC) *loc++ = *str++; *loc++ = *str++; } *loc = '\0'; amount = loc - expdest; STADJUST(amount, expdest); return loc; #endif /* BASH_SUBSTR */ } resetloc = expdest - (char *)stackblock(); #if BASH_PATTERN_SUBST /* We'll comeback here if we grow the stack while handling * a VSREPLACE or VSREPLACEALL, since our pointers into the * stack will need rebasing, and we'll need to remove our work * areas each time */ restart: #endif amount = expdest - ((char *)stackblock() + resetloc); STADJUST(-amount, expdest); startp = (char *)stackblock() + startloc; rmesc = startp; rmescend = (char *)stackblock() + strloc; if (quotes) { rmesc = rmescapes(startp, RMESCAPE_ALLOC | RMESCAPE_GROW); if (rmesc != startp) { rmescend = expdest; startp = (char *)stackblock() + startloc; } } rmescend--; str = (char *)stackblock() + strloc; /* * Example: v='a\bc'; echo ${v/\\b/_\\_\z_} * The result is a_\_z_c (not a\_\_z_c)! * * The search pattern and replace string treat backslashes differently! * RMESCAPE_SLASH causes preglob to work differently on the pattern * and string. It's only used on the first call. */ preglob(str, IF_BASH_PATTERN_SUBST( (subtype == VSREPLACE || subtype == VSREPLACEALL) && !repl ? RMESCAPE_SLASH : ) 0); #if BASH_PATTERN_SUBST workloc = expdest - (char *)stackblock(); if (subtype == VSREPLACE || subtype == VSREPLACEALL) { char *idx, *end; if (!repl) { repl = strchr(str, CTLESC); if (repl) *repl++ = '\0'; else repl = nullstr; } //bb_error_msg("str:'%s' repl:'%s'", str, repl); /* If there's no pattern to match, return the expansion unmolested */ if (str[0] == '\0') return NULL; len = 0; idx = startp; end = str - 1; while (idx < end) { try_to_match: loc = scanright(idx, rmesc, rmescend, str, quotes, 1); //bb_error_msg("scanright('%s'):'%s'", str, loc); if (!loc) { /* No match, advance */ char *restart_detect = stackblock(); skip_matching: STPUTC(*idx, expdest); if (quotes && (unsigned char)*idx == CTLESC) { idx++; len++; STPUTC(*idx, expdest); } if (stackblock() != restart_detect) goto restart; idx++; len++; rmesc++; /* continue; - prone to quadratic behavior, smarter code: */ if (idx >= end) break; if (str[0] == '*') { /* Pattern is "*foo". If "*foo" does not match "long_string", * it would never match "ong_string" etc, no point in trying. */ goto skip_matching; } goto try_to_match; } if (subtype == VSREPLACEALL) { while (idx < loc) { if (quotes && (unsigned char)*idx == CTLESC) idx++; idx++; rmesc++; } } else { idx = loc; } //bb_error_msg("repl:'%s'", repl); for (loc = (char*)repl; *loc; loc++) { char *restart_detect = stackblock(); if (quotes && *loc == '\\') { STPUTC(CTLESC, expdest); len++; } STPUTC(*loc, expdest); if (stackblock() != restart_detect) goto restart; len++; } if (subtype == VSREPLACE) { //bb_error_msg("tail:'%s', quotes:%x", idx, quotes); while (*idx) { char *restart_detect = stackblock(); STPUTC(*idx, expdest); if (stackblock() != restart_detect) goto restart; len++; idx++; } break; } } /* We've put the replaced text into a buffer at workloc, now * move it to the right place and adjust the stack. */ STPUTC('\0', expdest); startp = (char *)stackblock() + startloc; memmove(startp, (char *)stackblock() + workloc, len + 1); //bb_error_msg("startp:'%s'", startp); amount = expdest - (startp + len); STADJUST(-amount, expdest); return startp; } #endif /* BASH_PATTERN_SUBST */ subtype -= VSTRIMRIGHT; #if DEBUG if (subtype < 0 || subtype > 7) abort(); #endif /* zero = (subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX) */ zero = subtype >> 1; /* VSTRIMLEFT/VSTRIMRIGHTMAX -> scanleft */ scan = (subtype & 1) ^ zero ? scanleft : scanright; loc = scan(startp, rmesc, rmescend, str, quotes, zero); if (loc) { if (zero) { memmove(startp, loc, str - loc); loc = startp + (str - loc) - 1; } *loc = '\0'; amount = loc - expdest; STADJUST(amount, expdest); } return loc; } /* * Add the value of a specialized variable to the stack string. * name parameter (examples): * ash -c 'echo $1' name:'1=' * ash -c 'echo $qwe' name:'qwe=' * ash -c 'echo $$' name:'$=' * ash -c 'echo ${$}' name:'$=' * ash -c 'echo ${$##q}' name:'$=q' * ash -c 'echo ${#$}' name:'$=' * note: examples with bad shell syntax: * ash -c 'echo ${#$1}' name:'$=1' * ash -c 'echo ${#1#}' name:'1=#' */ static NOINLINE ssize_t varvalue(char *name, int varflags, int flags, struct strlist *var_str_list, int *quotedp) { const char *p; int num; int i; ssize_t len = 0; int sep; int quoted = *quotedp; int subtype = varflags & VSTYPE; int discard = subtype == VSPLUS || subtype == VSLENGTH; int quotes = (discard ? 0 : (flags & QUOTES_ESC)) | QUOTES_KEEPNUL; int syntax; sep = (flags & EXP_FULL) << CHAR_BIT; syntax = quoted ? DQSYNTAX : BASESYNTAX; switch (*name) { case '$': num = rootpid; goto numvar; case '?': num = exitstatus; goto numvar; case '#': num = shellparam.nparam; goto numvar; case '!': num = backgndpid; if (num == 0) return -1; numvar: len = cvtnum(num); goto check_1char_name; case '-': expdest = makestrspace(NOPTS, expdest); for (i = NOPTS - 1; i >= 0; i--) { if (optlist[i]) { USTPUTC(optletters(i), expdest); len++; } } check_1char_name: #if 0 /* handles cases similar to ${#$1} */ if (name[2] != '\0') raise_error_syntax("bad substitution"); #endif break; case '@': if (quoted && sep) goto param; /* fall through */ case '*': { char **ap; char sepc; if (quoted) sep = 0; sep |= ifsset() ? ifsval()[0] : ' '; param: sepc = sep; *quotedp = !sepc; ap = shellparam.p; if (!ap) return -1; while ((p = *ap++) != NULL) { len += strtodest(p, syntax, quotes); if (*ap && sep) { len++; memtodest(&sepc, 1, syntax, quotes); } } break; } /* case '*' */ case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': num = atoi(name); /* number(name) fails on ${N#str} etc */ if (num < 0 || num > shellparam.nparam) return -1; p = num ? shellparam.p[num - 1] : arg0; goto value; default: /* NB: name has form "VAR=..." */ /* "A=a B=$A" case: var_str_list is a list of "A=a" strings * which should be considered before we check variables. */ if (var_str_list) { unsigned name_len = (strchrnul(name, '=') - name) + 1; p = NULL; do { char *str, *eq; str = var_str_list->text; eq = strchr(str, '='); if (!eq) /* stop at first non-assignment */ break; eq++; if (name_len == (unsigned)(eq - str) && strncmp(str, name, name_len) == 0 ) { p = eq; /* goto value; - WRONG! */ /* think "A=1 A=2 B=$A" */ } var_str_list = var_str_list->next; } while (var_str_list); if (p) goto value; } p = lookupvar(name); value: if (!p) return -1; len = strtodest(p, syntax, quotes); #if ENABLE_UNICODE_SUPPORT if (subtype == VSLENGTH && len > 0) { reinit_unicode_for_ash(); if (unicode_status == UNICODE_ON) { STADJUST(-len, expdest); discard = 0; len = unicode_strlen(p); } } #endif break; } if (discard) STADJUST(-len, expdest); return len; } /* * Expand a variable, and return a pointer to the next character in the * input string. */ static char * evalvar(char *p, int flag, struct strlist *var_str_list) { char varflags; char subtype; int quoted; char easy; char *var; int patloc; int startloc; ssize_t varlen; varflags = (unsigned char) *p++; subtype = varflags & VSTYPE; if (!subtype) raise_error_syntax("bad substitution"); quoted = flag & EXP_QUOTED; var = p; easy = (!quoted || (*var == '@' && shellparam.nparam)); startloc = expdest - (char *)stackblock(); p = strchr(p, '=') + 1; //TODO: use var_end(p)? again: varlen = varvalue(var, varflags, flag, var_str_list, "ed); if (varflags & VSNUL) varlen--; if (subtype == VSPLUS) { varlen = -1 - varlen; goto vsplus; } if (subtype == VSMINUS) { vsplus: if (varlen < 0) { argstr( p, flag | EXP_TILDE | EXP_WORD, var_str_list ); goto end; } goto record; } if (subtype == VSASSIGN || subtype == VSQUESTION) { if (varlen >= 0) goto record; subevalvar(p, var, 0, subtype, startloc, varflags, flag & ~QUOTES_ESC, var_str_list); varflags &= ~VSNUL; /* * Remove any recorded regions beyond * start of variable */ removerecordregions(startloc); goto again; } if (varlen < 0 && uflag) varunset(p, var, 0, 0); if (subtype == VSLENGTH) { cvtnum(varlen > 0 ? varlen : 0); goto record; } if (subtype == VSNORMAL) { record: if (!easy) goto end; recordregion(startloc, expdest - (char *)stackblock(), quoted); goto end; } #if DEBUG switch (subtype) { case VSTRIMLEFT: case VSTRIMLEFTMAX: case VSTRIMRIGHT: case VSTRIMRIGHTMAX: #if BASH_SUBSTR case VSSUBSTR: #endif #if BASH_PATTERN_SUBST case VSREPLACE: case VSREPLACEALL: #endif break; default: abort(); } #endif if (varlen >= 0) { /* * Terminate the string and start recording the pattern * right after it */ STPUTC('\0', expdest); patloc = expdest - (char *)stackblock(); if (NULL == subevalvar(p, /* varname: */ NULL, patloc, subtype, startloc, varflags, flag, var_str_list)) { int amount = expdest - ( (char *)stackblock() + patloc - 1 ); STADJUST(-amount, expdest); } /* Remove any recorded regions beyond start of variable */ removerecordregions(startloc); goto record; } end: if (subtype != VSNORMAL) { /* skip to end of alternative */ int nesting = 1; for (;;) { unsigned char c = *p++; if (c == CTLESC) p++; else if (c == CTLBACKQ) { if (varlen >= 0) argbackq = argbackq->next; } else if (c == CTLVAR) { if ((*p++ & VSTYPE) != VSNORMAL) nesting++; } else if (c == CTLENDVAR) { if (--nesting == 0) break; } } } return p; } /* * Add a file name to the list. */ static void addfname(const char *name) { struct strlist *sp; sp = stzalloc(sizeof(*sp)); sp->text = sstrdup(name); *exparg.lastp = sp; exparg.lastp = &sp->next; } /* Avoid glob() (and thus, stat() et al) for words like "echo" */ static int hasmeta(const char *p) { static const char chars[] ALIGN1 = { '*', '?', '[', '\\', CTLQUOTEMARK, CTLESC, 0 }; for (;;) { p = strpbrk(p, chars); if (!p) break; switch ((unsigned char) *p) { case CTLQUOTEMARK: for (;;) { p++; if (*p == CTLQUOTEMARK) break; if (*p == CTLESC) p++; if (*p == '\0') /* huh? */ return 0; } break; case '\\': case CTLESC: p++; if (*p == '\0') return 0; break; case '[': if (!strchr(p + 1, ']')) { /* It's not a properly closed [] pattern, * but other metas may follow. Continue checking. * my[file* _is_ globbed by bash * and matches filenames like "my[file1". */ break; } /* fallthrough */ default: /* case '*': */ /* case '?': */ return 1; } p++; } return 0; } /* If we want to use glob() from libc... */ #if !ENABLE_ASH_INTERNAL_GLOB /* Add the result of glob() to the list */ static void addglob(const glob_t *pglob) { char **p = pglob->gl_pathv; do { addfname(*p); } while (*++p); } static void expandmeta(struct strlist *str /*, int flag*/) { /* TODO - EXP_REDIR */ while (str) { char *p; glob_t pglob; int i; if (fflag) goto nometa; if (!hasmeta(str->text)) goto nometa; INT_OFF; p = preglob(str->text, RMESCAPE_ALLOC | RMESCAPE_HEAP); // GLOB_NOMAGIC (GNU): if no *?[ chars in pattern, return it even if no match // GLOB_NOCHECK: if no match, return unchanged pattern (sans \* escapes?) // // glibc 2.24.90 glob(GLOB_NOMAGIC) does not remove backslashes used for escaping: // if you pass it "file\?", it returns "file\?", not "file?", if no match. // Which means you need to unescape the string, right? Not so fast: // if there _is_ a file named "file\?" (with backslash), it is returned // as "file\?" too (whichever pattern you used to find it, say, "file*"). // You DON'T KNOW by looking at the result whether you need to unescape it. // // Worse, globbing of "file\?" in a directory with two files, "file?" and "file\?", // returns "file\?" - which is WRONG: "file\?" pattern matches "file?" file. // Without GLOB_NOMAGIC, this works correctly ("file?" is returned as a match). // With GLOB_NOMAGIC | GLOB_NOCHECK, this also works correctly. // i = glob(p, GLOB_NOMAGIC | GLOB_NOCHECK, NULL, &pglob); // i = glob(p, GLOB_NOMAGIC, NULL, &pglob); i = glob(p, 0, NULL, &pglob); //bb_error_msg("glob('%s'):%d '%s'...", p, i, pglob.gl_pathv ? pglob.gl_pathv[0] : "-"); if (p != str->text) free(p); switch (i) { case 0: #if 0 // glibc 2.24.90 bug? Patterns like "*/file", when match, don't set GLOB_MAGCHAR /* GLOB_MAGCHAR is set if *?[ chars were seen (GNU) */ if (!(pglob.gl_flags & GLOB_MAGCHAR)) goto nometa2; #endif addglob(&pglob); globfree(&pglob); INT_ON; break; case GLOB_NOMATCH: //nometa2: globfree(&pglob); INT_ON; nometa: *exparg.lastp = str; rmescapes(str->text, 0); exparg.lastp = &str->next; break; default: /* GLOB_NOSPACE */ globfree(&pglob); INT_ON; ash_msg_and_raise_error(bb_msg_memory_exhausted); } str = str->next; } } #else /* ENABLE_ASH_INTERNAL_GLOB: Homegrown globbing code. (dash also has both, uses homegrown one.) */ /* * Do metacharacter (i.e. *, ?, [...]) expansion. */ static void expmeta(char *expdir, char *enddir, char *name) { char *p; const char *cp; char *start; char *endname; int metaflag; struct stat statb; DIR *dirp; struct dirent *dp; int atend; int matchdot; int esc; metaflag = 0; start = name; for (p = name; esc = 0, *p; p += esc + 1) { if (*p == '*' || *p == '?') metaflag = 1; else if (*p == '[') { char *q = p + 1; if (*q == '!') q++; for (;;) { if (*q == '\\') q++; if (*q == '/' || *q == '\0') break; if (*++q == ']') { metaflag = 1; break; } } } else { if (*p == '\\') esc++; if (p[esc] == '/') { if (metaflag) break; start = p + esc + 1; } } } if (metaflag == 0) { /* we've reached the end of the file name */ if (enddir != expdir) metaflag++; p = name; do { if (*p == '\\') p++; *enddir++ = *p; } while (*p++); if (metaflag == 0 || lstat(expdir, &statb) >= 0) addfname(expdir); return; } endname = p; if (name < start) { p = name; do { if (*p == '\\') p++; *enddir++ = *p++; } while (p < start); } if (enddir == expdir) { cp = "."; } else if (enddir == expdir + 1 && *expdir == '/') { cp = "/"; } else { cp = expdir; enddir[-1] = '\0'; } dirp = opendir(cp); if (dirp == NULL) return; if (enddir != expdir) enddir[-1] = '/'; if (*endname == 0) { atend = 1; } else { atend = 0; *endname = '\0'; endname += esc + 1; } matchdot = 0; p = start; if (*p == '\\') p++; if (*p == '.') matchdot++; while (!pending_int && (dp = readdir(dirp)) != NULL) { if (dp->d_name[0] == '.' && !matchdot) continue; if (pmatch(start, dp->d_name)) { if (atend) { strcpy(enddir, dp->d_name); addfname(expdir); } else { for (p = enddir, cp = dp->d_name; (*p++ = *cp++) != '\0';) continue; p[-1] = '/'; expmeta(expdir, p, endname); } } } closedir(dirp); if (!atend) endname[-esc - 1] = esc ? '\\' : '/'; } static struct strlist * msort(struct strlist *list, int len) { struct strlist *p, *q = NULL; struct strlist **lpp; int half; int n; if (len <= 1) return list; half = len >> 1; p = list; for (n = half; --n >= 0;) { q = p; p = p->next; } q->next = NULL; /* terminate first half of list */ q = msort(list, half); /* sort first half of list */ p = msort(p, len - half); /* sort second half */ lpp = &list; for (;;) { #if ENABLE_LOCALE_SUPPORT if (strcoll(p->text, q->text) < 0) #else if (strcmp(p->text, q->text) < 0) #endif { *lpp = p; lpp = &p->next; p = *lpp; if (p == NULL) { *lpp = q; break; } } else { *lpp = q; lpp = &q->next; q = *lpp; if (q == NULL) { *lpp = p; break; } } } return list; } /* * Sort the results of file name expansion. It calculates the number of * strings to sort and then calls msort (short for merge sort) to do the * work. */ static struct strlist * expsort(struct strlist *str) { int len; struct strlist *sp; len = 0; for (sp = str; sp; sp = sp->next) len++; return msort(str, len); } static void expandmeta(struct strlist *str /*, int flag*/) { /* TODO - EXP_REDIR */ while (str) { char *expdir; struct strlist **savelastp; struct strlist *sp; char *p; if (fflag) goto nometa; if (!hasmeta(str->text)) goto nometa; savelastp = exparg.lastp; INT_OFF; p = preglob(str->text, RMESCAPE_ALLOC | RMESCAPE_HEAP); { int i = strlen(str->text); //BUGGY estimation of how long expanded name can be expdir = ckmalloc(i < 2048 ? 2048 : i+1); } expmeta(expdir, expdir, p); free(expdir); if (p != str->text) free(p); INT_ON; if (exparg.lastp == savelastp) { /* * no matches */ nometa: *exparg.lastp = str; rmescapes(str->text, 0); exparg.lastp = &str->next; } else { *exparg.lastp = NULL; *savelastp = sp = expsort(*savelastp); while (sp->next != NULL) sp = sp->next; exparg.lastp = &sp->next; } str = str->next; } } #endif /* ENABLE_ASH_INTERNAL_GLOB */ /* * Perform variable substitution and command substitution on an argument, * placing the resulting list of arguments in arglist. If EXP_FULL is true, * perform splitting and file name expansion. When arglist is NULL, perform * here document expansion. */ static void expandarg(union node *arg, struct arglist *arglist, int flag) { struct strlist *sp; char *p; argbackq = arg->narg.backquote; STARTSTACKSTR(expdest); TRACE(("expandarg: argstr('%s',flags:%x)\n", arg->narg.text, flag)); argstr(arg->narg.text, flag, /* var_str_list: */ arglist ? arglist->list : NULL); p = _STPUTC('\0', expdest); expdest = p - 1; if (arglist == NULL) { /* here document expanded */ goto out; } p = grabstackstr(p); TRACE(("expandarg: p:'%s'\n", p)); exparg.lastp = &exparg.list; /* * TODO - EXP_REDIR */ if (flag & EXP_FULL) { ifsbreakup(p, &exparg); *exparg.lastp = NULL; exparg.lastp = &exparg.list; expandmeta(exparg.list /*, flag*/); } else { if (flag & EXP_REDIR) { /*XXX - for now, just remove escapes */ rmescapes(p, 0); TRACE(("expandarg: rmescapes:'%s'\n", p)); } sp = stzalloc(sizeof(*sp)); sp->text = p; *exparg.lastp = sp; exparg.lastp = &sp->next; } *exparg.lastp = NULL; if (exparg.list) { *arglist->lastp = exparg.list; arglist->lastp = exparg.lastp; } out: ifsfree(); } /* * Expand shell variables and backquotes inside a here document. */ static void expandhere(union node *arg, int fd) { expandarg(arg, (struct arglist *)NULL, EXP_QUOTED); full_write(fd, stackblock(), expdest - (char *)stackblock()); } /* * Returns true if the pattern matches the string. */ static int patmatch(char *pattern, const char *string) { return pmatch(preglob(pattern, 0), string); } /* * See if a pattern matches in a case statement. */ static int casematch(union node *pattern, char *val) { struct stackmark smark; int result; setstackmark(&smark); argbackq = pattern->narg.backquote; STARTSTACKSTR(expdest); argstr(pattern->narg.text, EXP_TILDE | EXP_CASE, /* var_str_list: */ NULL); STACKSTRNUL(expdest); ifsfree(); result = patmatch(stackblock(), val); popstackmark(&smark); return result; } /* ============ find_command */ struct builtincmd { const char *name; int (*builtin)(int, char **) FAST_FUNC; /* unsigned flags; */ }; #define IS_BUILTIN_SPECIAL(b) ((b)->name[0] & 1) /* "regular" builtins always take precedence over commands, * regardless of PATH=....%builtin... position */ #define IS_BUILTIN_REGULAR(b) ((b)->name[0] & 2) #define IS_BUILTIN_ASSIGN(b) ((b)->name[0] & 4) struct cmdentry { smallint cmdtype; /* CMDxxx */ union param { int index; /* index >= 0 for commands without path (slashes) */ /* (TODO: what exactly does the value mean? PATH position?) */ /* index == -1 for commands with slashes */ /* index == (-2 - applet_no) for NOFORK applets */ const struct builtincmd *cmd; struct funcnode *func; } u; }; /* values of cmdtype */ #define CMDUNKNOWN -1 /* no entry in table for command */ #define CMDNORMAL 0 /* command is an executable program */ #define CMDFUNCTION 1 /* command is a shell function */ #define CMDBUILTIN 2 /* command is a shell builtin */ /* action to find_command() */ #define DO_ERR 0x01 /* prints errors */ #define DO_ABS 0x02 /* checks absolute paths */ #define DO_NOFUNC 0x04 /* don't return shell functions, for command */ #define DO_ALTPATH 0x08 /* using alternate path */ #define DO_ALTBLTIN 0x20 /* %builtin in alt. path */ static void find_command(char *, struct cmdentry *, int, const char *); /* ============ Hashing commands */ /* * When commands are first encountered, they are entered in a hash table. * This ensures that a full path search will not have to be done for them * on each invocation. * * We should investigate converting to a linear search, even though that * would make the command name "hash" a misnomer. */ struct tblentry { struct tblentry *next; /* next entry in hash chain */ union param param; /* definition of builtin function */ smallint cmdtype; /* CMDxxx */ char rehash; /* if set, cd done since entry created */ char cmdname[1]; /* name of command */ }; static struct tblentry **cmdtable; #define INIT_G_cmdtable() do { \ cmdtable = xzalloc(CMDTABLESIZE * sizeof(cmdtable[0])); \ } while (0) static int builtinloc = -1; /* index in path of %builtin, or -1 */ static void tryexec(IF_FEATURE_SH_STANDALONE(int applet_no,) char *cmd, char **argv, char **envp) { #if ENABLE_FEATURE_SH_STANDALONE if (applet_no >= 0) { if (APPLET_IS_NOEXEC(applet_no)) { clearenv(); while (*envp) putenv(*envp++); run_applet_no_and_exit(applet_no, argv); } /* re-exec ourselves with the new arguments */ execve(bb_busybox_exec_path, argv, envp); /* If they called chroot or otherwise made the binary no longer * executable, fall through */ } #endif repeat: #ifdef SYSV do { execve(cmd, argv, envp); } while (errno == EINTR); #else execve(cmd, argv, envp); #endif if (cmd != (char*) bb_busybox_exec_path && errno == ENOEXEC) { /* Run "cmd" as a shell script: * http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html * "If the execve() function fails with ENOEXEC, the shell * shall execute a command equivalent to having a shell invoked * with the command name as its first operand, * with any remaining arguments passed to the new shell" * * That is, do not use $SHELL, user's shell, or /bin/sh; * just call ourselves. * * Note that bash reads ~80 chars of the file, and if it sees * a zero byte before it sees newline, it doesn't try to * interpret it, but fails with "cannot execute binary file" * message and exit code 126. For one, this prevents attempts * to interpret foreign ELF binaries as shell scripts. */ argv[0] = cmd; cmd = (char*) bb_busybox_exec_path; /* NB: this is only possible because all callers of shellexec() * ensure that the argv[-1] slot exists! */ argv--; argv[0] = (char*) "ash"; goto repeat; } } /* * Exec a program. Never returns. If you change this routine, you may * have to change the find_command routine as well. * argv[-1] must exist and be writable! See tryexec() for why. */ static void shellexec(char *prog, char **argv, const char *path, int idx) NORETURN; static void shellexec(char *prog, char **argv, const char *path, int idx) { char *cmdname; int e; char **envp; int exerrno; int applet_no = -1; /* used only by FEATURE_SH_STANDALONE */ envp = listvars(VEXPORT, VUNSET, /*end:*/ NULL); if (strchr(prog, '/') != NULL #if ENABLE_FEATURE_SH_STANDALONE || (applet_no = find_applet_by_name(prog)) >= 0 #endif ) { tryexec(IF_FEATURE_SH_STANDALONE(applet_no,) prog, argv, envp); if (applet_no >= 0) { /* We tried execing ourself, but it didn't work. * Maybe /proc/self/exe doesn't exist? * Try $PATH search. */ goto try_PATH; } e = errno; } else { try_PATH: e = ENOENT; while ((cmdname = path_advance(&path, prog)) != NULL) { if (--idx < 0 && pathopt == NULL) { tryexec(IF_FEATURE_SH_STANDALONE(-1,) cmdname, argv, envp); if (errno != ENOENT && errno != ENOTDIR) e = errno; } stunalloc(cmdname); } } /* Map to POSIX errors */ switch (e) { case EACCES: exerrno = 126; break; case ENOENT: exerrno = 127; break; default: exerrno = 2; break; } exitstatus = exerrno; TRACE(("shellexec failed for %s, errno %d, suppress_int %d\n", prog, e, suppress_int)); ash_msg_and_raise(EXEXIT, "%s: %s", prog, errmsg(e, "not found")); /* NOTREACHED */ } static void printentry(struct tblentry *cmdp) { int idx; const char *path; char *name; idx = cmdp->param.index; path = pathval(); do { name = path_advance(&path, cmdp->cmdname); stunalloc(name); } while (--idx >= 0); out1fmt("%s%s\n", name, (cmdp->rehash ? "*" : nullstr)); } /* * Clear out command entries. The argument specifies the first entry in * PATH which has changed. */ static void clearcmdentry(int firstchange) { struct tblentry **tblp; struct tblentry **pp; struct tblentry *cmdp; INT_OFF; for (tblp = cmdtable; tblp < &cmdtable[CMDTABLESIZE]; tblp++) { pp = tblp; while ((cmdp = *pp) != NULL) { if ((cmdp->cmdtype == CMDNORMAL && cmdp->param.index >= firstchange) || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= firstchange) ) { *pp = cmdp->next; free(cmdp); } else { pp = &cmdp->next; } } } INT_ON; } /* * Locate a command in the command hash table. If "add" is nonzero, * add the command to the table if it is not already present. The * variable "lastcmdentry" is set to point to the address of the link * pointing to the entry, so that delete_cmd_entry can delete the * entry. * * Interrupts must be off if called with add != 0. */ static struct tblentry **lastcmdentry; static struct tblentry * cmdlookup(const char *name, int add) { unsigned int hashval; const char *p; struct tblentry *cmdp; struct tblentry **pp; p = name; hashval = (unsigned char)*p << 4; while (*p) hashval += (unsigned char)*p++; hashval &= 0x7FFF; pp = &cmdtable[hashval % CMDTABLESIZE]; for (cmdp = *pp; cmdp; cmdp = cmdp->next) { if (strcmp(cmdp->cmdname, name) == 0) break; pp = &cmdp->next; } if (add && cmdp == NULL) { cmdp = *pp = ckzalloc(sizeof(struct tblentry) + strlen(name) /* + 1 - already done because * tblentry::cmdname is char[1] */); /*cmdp->next = NULL; - ckzalloc did it */ cmdp->cmdtype = CMDUNKNOWN; strcpy(cmdp->cmdname, name); } lastcmdentry = pp; return cmdp; } /* * Delete the command entry returned on the last lookup. */ static void delete_cmd_entry(void) { struct tblentry *cmdp; INT_OFF; cmdp = *lastcmdentry; *lastcmdentry = cmdp->next; if (cmdp->cmdtype == CMDFUNCTION) freefunc(cmdp->param.func); free(cmdp); INT_ON; } /* * Add a new command entry, replacing any existing command entry for * the same name - except special builtins. */ static void addcmdentry(char *name, struct cmdentry *entry) { struct tblentry *cmdp; cmdp = cmdlookup(name, 1); if (cmdp->cmdtype == CMDFUNCTION) { freefunc(cmdp->param.func); } cmdp->cmdtype = entry->cmdtype; cmdp->param = entry->u; cmdp->rehash = 0; } static int FAST_FUNC hashcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { struct tblentry **pp; struct tblentry *cmdp; int c; struct cmdentry entry; char *name; if (nextopt("r") != '\0') { clearcmdentry(0); return 0; } if (*argptr == NULL) { for (pp = cmdtable; pp < &cmdtable[CMDTABLESIZE]; pp++) { for (cmdp = *pp; cmdp; cmdp = cmdp->next) { if (cmdp->cmdtype == CMDNORMAL) printentry(cmdp); } } return 0; } c = 0; while ((name = *argptr) != NULL) { cmdp = cmdlookup(name, 0); if (cmdp != NULL && (cmdp->cmdtype == CMDNORMAL || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)) ) { delete_cmd_entry(); } find_command(name, &entry, DO_ERR, pathval()); if (entry.cmdtype == CMDUNKNOWN) c = 1; argptr++; } return c; } /* * Called when a cd is done. Marks all commands so the next time they * are executed they will be rehashed. */ static void hashcd(void) { struct tblentry **pp; struct tblentry *cmdp; for (pp = cmdtable; pp < &cmdtable[CMDTABLESIZE]; pp++) { for (cmdp = *pp; cmdp; cmdp = cmdp->next) { if (cmdp->cmdtype == CMDNORMAL || (cmdp->cmdtype == CMDBUILTIN && !IS_BUILTIN_REGULAR(cmdp->param.cmd) && builtinloc > 0) ) { cmdp->rehash = 1; } } } } /* * Fix command hash table when PATH changed. * Called before PATH is changed. The argument is the new value of PATH; * pathval() still returns the old value at this point. * Called with interrupts off. */ static void FAST_FUNC changepath(const char *new) { const char *old; int firstchange; int idx; int idx_bltin; old = pathval(); firstchange = 9999; /* assume no change */ idx = 0; idx_bltin = -1; for (;;) { if (*old != *new) { firstchange = idx; if ((*old == '\0' && *new == ':') || (*old == ':' && *new == '\0') ) { firstchange++; } old = new; /* ignore subsequent differences */ } if (*new == '\0') break; if (*new == '%' && idx_bltin < 0 && prefix(new + 1, "builtin")) idx_bltin = idx; if (*new == ':') idx++; new++; old++; } if (builtinloc < 0 && idx_bltin >= 0) builtinloc = idx_bltin; /* zap builtins */ if (builtinloc >= 0 && idx_bltin < 0) firstchange = 0; clearcmdentry(firstchange); builtinloc = idx_bltin; } enum { TEOF, TNL, TREDIR, TWORD, TSEMI, TBACKGND, TAND, TOR, TPIPE, TLP, TRP, TENDCASE, TENDBQUOTE, TNOT, TCASE, TDO, TDONE, TELIF, TELSE, TESAC, TFI, TFOR, #if BASH_FUNCTION TFUNCTION, #endif TIF, TIN, TTHEN, TUNTIL, TWHILE, TBEGIN, TEND }; typedef smallint token_id_t; /* Nth bit indicates if token marks the end of a list */ enum { tokendlist = 0 /* 0 */ | (1u << TEOF) /* 1 */ | (0u << TNL) /* 2 */ | (0u << TREDIR) /* 3 */ | (0u << TWORD) /* 4 */ | (0u << TSEMI) /* 5 */ | (0u << TBACKGND) /* 6 */ | (0u << TAND) /* 7 */ | (0u << TOR) /* 8 */ | (0u << TPIPE) /* 9 */ | (0u << TLP) /* 10 */ | (1u << TRP) /* 11 */ | (1u << TENDCASE) /* 12 */ | (1u << TENDBQUOTE) /* 13 */ | (0u << TNOT) /* 14 */ | (0u << TCASE) /* 15 */ | (1u << TDO) /* 16 */ | (1u << TDONE) /* 17 */ | (1u << TELIF) /* 18 */ | (1u << TELSE) /* 19 */ | (1u << TESAC) /* 20 */ | (1u << TFI) /* 21 */ | (0u << TFOR) #if BASH_FUNCTION /* 22 */ | (0u << TFUNCTION) #endif /* 23 */ | (0u << TIF) /* 24 */ | (0u << TIN) /* 25 */ | (1u << TTHEN) /* 26 */ | (0u << TUNTIL) /* 27 */ | (0u << TWHILE) /* 28 */ | (0u << TBEGIN) /* 29 */ | (1u << TEND) , /* thus far 29 bits used */ }; static const char *const tokname_array[] = { "end of file", "newline", "redirection", "word", ";", "&", "&&", "||", "|", "(", ")", ";;", "`", #define KWDOFFSET 13 /* the following are keywords */ "!", "case", "do", "done", "elif", "else", "esac", "fi", "for", #if BASH_FUNCTION "function", #endif "if", "in", "then", "until", "while", "{", "}", }; /* Wrapper around strcmp for qsort/bsearch/... */ static int pstrcmp(const void *a, const void *b) { return strcmp((char*)a, *(char**)b); } static const char *const * findkwd(const char *s) { return bsearch(s, tokname_array + KWDOFFSET, ARRAY_SIZE(tokname_array) - KWDOFFSET, sizeof(tokname_array[0]), pstrcmp); } /* * Locate and print what a word is... */ static int describe_command(char *command, const char *path, int describe_command_verbose) { struct cmdentry entry; #if ENABLE_ASH_ALIAS const struct alias *ap; #endif path = path ? path : pathval(); if (describe_command_verbose) { out1str(command); } /* First look at the keywords */ if (findkwd(command)) { out1str(describe_command_verbose ? " is a shell keyword" : command); goto out; } #if ENABLE_ASH_ALIAS /* Then look at the aliases */ ap = lookupalias(command, 0); if (ap != NULL) { if (!describe_command_verbose) { out1str("alias "); printalias(ap); return 0; } out1fmt(" is an alias for %s", ap->val); goto out; } #endif /* Brute force */ find_command(command, &entry, DO_ABS, path); switch (entry.cmdtype) { case CMDNORMAL: { int j = entry.u.index; char *p; if (j < 0) { p = command; } else { do { p = path_advance(&path, command); stunalloc(p); } while (--j >= 0); } if (describe_command_verbose) { out1fmt(" is %s", p); } else { out1str(p); } break; } case CMDFUNCTION: if (describe_command_verbose) { out1str(" is a shell function"); } else { out1str(command); } break; case CMDBUILTIN: if (describe_command_verbose) { out1fmt(" is a %sshell builtin", IS_BUILTIN_SPECIAL(entry.u.cmd) ? "special " : nullstr ); } else { out1str(command); } break; default: if (describe_command_verbose) { out1str(": not found\n"); } return 127; } out: out1str("\n"); return 0; } static int FAST_FUNC typecmd(int argc UNUSED_PARAM, char **argv) { int i = 1; int err = 0; int verbose = 1; /* type -p ... ? (we don't bother checking for 'p') */ if (argv[1] && argv[1][0] == '-') { i++; verbose = 0; } while (argv[i]) { err |= describe_command(argv[i++], NULL, verbose); } return err; } #if ENABLE_ASH_CMDCMD /* Is it "command [-p] PROG ARGS" bltin, no other opts? Return ptr to "PROG" if yes */ static char ** parse_command_args(char **argv, const char **path) { char *cp, c; for (;;) { cp = *++argv; if (!cp) return NULL; if (*cp++ != '-') break; c = *cp++; if (!c) break; if (c == '-' && !*cp) { if (!*++argv) return NULL; break; } do { switch (c) { case 'p': *path = bb_default_path; break; default: /* run 'typecmd' for other options */ return NULL; } c = *cp++; } while (c); } return argv; } static int FAST_FUNC commandcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { char *cmd; int c; enum { VERIFY_BRIEF = 1, VERIFY_VERBOSE = 2, } verify = 0; const char *path = NULL; /* "command [-p] PROG ARGS" (that is, without -V or -v) * never reaches this function. */ while ((c = nextopt("pvV")) != '\0') if (c == 'V') verify |= VERIFY_VERBOSE; else if (c == 'v') /*verify |= VERIFY_BRIEF*/; #if DEBUG else if (c != 'p') abort(); #endif else path = bb_default_path; /* Mimic bash: just "command -v" doesn't complain, it's a nop */ cmd = *argptr; if (/*verify && */ cmd) return describe_command(cmd, path, verify /* - VERIFY_BRIEF*/); return 0; } #endif /*static int funcblocksize; // size of structures in function */ /*static int funcstringsize; // size of strings in node */ static void *funcblock; /* block to allocate function from */ static char *funcstring_end; /* end of block to allocate strings from */ /* flags in argument to evaltree */ #define EV_EXIT 01 /* exit after evaluating tree */ #define EV_TESTED 02 /* exit status is checked; ignore -e flag */ static const uint8_t nodesize[N_NUMBER] ALIGN1 = { [NCMD ] = SHELL_ALIGN(sizeof(struct ncmd)), [NPIPE ] = SHELL_ALIGN(sizeof(struct npipe)), [NREDIR ] = SHELL_ALIGN(sizeof(struct nredir)), [NBACKGND ] = SHELL_ALIGN(sizeof(struct nredir)), [NSUBSHELL] = SHELL_ALIGN(sizeof(struct nredir)), [NAND ] = SHELL_ALIGN(sizeof(struct nbinary)), [NOR ] = SHELL_ALIGN(sizeof(struct nbinary)), [NSEMI ] = SHELL_ALIGN(sizeof(struct nbinary)), [NIF ] = SHELL_ALIGN(sizeof(struct nif)), [NWHILE ] = SHELL_ALIGN(sizeof(struct nbinary)), [NUNTIL ] = SHELL_ALIGN(sizeof(struct nbinary)), [NFOR ] = SHELL_ALIGN(sizeof(struct nfor)), [NCASE ] = SHELL_ALIGN(sizeof(struct ncase)), [NCLIST ] = SHELL_ALIGN(sizeof(struct nclist)), [NDEFUN ] = SHELL_ALIGN(sizeof(struct narg)), [NARG ] = SHELL_ALIGN(sizeof(struct narg)), [NTO ] = SHELL_ALIGN(sizeof(struct nfile)), #if BASH_REDIR_OUTPUT [NTO2 ] = SHELL_ALIGN(sizeof(struct nfile)), #endif [NCLOBBER ] = SHELL_ALIGN(sizeof(struct nfile)), [NFROM ] = SHELL_ALIGN(sizeof(struct nfile)), [NFROMTO ] = SHELL_ALIGN(sizeof(struct nfile)), [NAPPEND ] = SHELL_ALIGN(sizeof(struct nfile)), [NTOFD ] = SHELL_ALIGN(sizeof(struct ndup)), [NFROMFD ] = SHELL_ALIGN(sizeof(struct ndup)), [NHERE ] = SHELL_ALIGN(sizeof(struct nhere)), [NXHERE ] = SHELL_ALIGN(sizeof(struct nhere)), [NNOT ] = SHELL_ALIGN(sizeof(struct nnot)), }; static int calcsize(int funcblocksize, union node *n); static int sizenodelist(int funcblocksize, struct nodelist *lp) { while (lp) { funcblocksize += SHELL_ALIGN(sizeof(struct nodelist)); funcblocksize = calcsize(funcblocksize, lp->n); lp = lp->next; } return funcblocksize; } static int calcsize(int funcblocksize, union node *n) { if (n == NULL) return funcblocksize; funcblocksize += nodesize[n->type]; switch (n->type) { case NCMD: funcblocksize = calcsize(funcblocksize, n->ncmd.redirect); funcblocksize = calcsize(funcblocksize, n->ncmd.args); funcblocksize = calcsize(funcblocksize, n->ncmd.assign); break; case NPIPE: funcblocksize = sizenodelist(funcblocksize, n->npipe.cmdlist); break; case NREDIR: case NBACKGND: case NSUBSHELL: funcblocksize = calcsize(funcblocksize, n->nredir.redirect); funcblocksize = calcsize(funcblocksize, n->nredir.n); break; case NAND: case NOR: case NSEMI: case NWHILE: case NUNTIL: funcblocksize = calcsize(funcblocksize, n->nbinary.ch2); funcblocksize = calcsize(funcblocksize, n->nbinary.ch1); break; case NIF: funcblocksize = calcsize(funcblocksize, n->nif.elsepart); funcblocksize = calcsize(funcblocksize, n->nif.ifpart); funcblocksize = calcsize(funcblocksize, n->nif.test); break; case NFOR: funcblocksize += SHELL_ALIGN(strlen(n->nfor.var) + 1); /* was funcstringsize += ... */ funcblocksize = calcsize(funcblocksize, n->nfor.body); funcblocksize = calcsize(funcblocksize, n->nfor.args); break; case NCASE: funcblocksize = calcsize(funcblocksize, n->ncase.cases); funcblocksize = calcsize(funcblocksize, n->ncase.expr); break; case NCLIST: funcblocksize = calcsize(funcblocksize, n->nclist.body); funcblocksize = calcsize(funcblocksize, n->nclist.pattern); funcblocksize = calcsize(funcblocksize, n->nclist.next); break; case NDEFUN: case NARG: funcblocksize = sizenodelist(funcblocksize, n->narg.backquote); funcblocksize += SHELL_ALIGN(strlen(n->narg.text) + 1); /* was funcstringsize += ... */ funcblocksize = calcsize(funcblocksize, n->narg.next); break; case NTO: #if BASH_REDIR_OUTPUT case NTO2: #endif case NCLOBBER: case NFROM: case NFROMTO: case NAPPEND: funcblocksize = calcsize(funcblocksize, n->nfile.fname); funcblocksize = calcsize(funcblocksize, n->nfile.next); break; case NTOFD: case NFROMFD: funcblocksize = calcsize(funcblocksize, n->ndup.vname); funcblocksize = calcsize(funcblocksize, n->ndup.next); break; case NHERE: case NXHERE: funcblocksize = calcsize(funcblocksize, n->nhere.doc); funcblocksize = calcsize(funcblocksize, n->nhere.next); break; case NNOT: funcblocksize = calcsize(funcblocksize, n->nnot.com); break; }; return funcblocksize; } static char * nodeckstrdup(char *s) { funcstring_end -= SHELL_ALIGN(strlen(s) + 1); return strcpy(funcstring_end, s); } static union node *copynode(union node *); static struct nodelist * copynodelist(struct nodelist *lp) { struct nodelist *start; struct nodelist **lpp; lpp = &start; while (lp) { *lpp = funcblock; funcblock = (char *) funcblock + SHELL_ALIGN(sizeof(struct nodelist)); (*lpp)->n = copynode(lp->n); lp = lp->next; lpp = &(*lpp)->next; } *lpp = NULL; return start; } static union node * copynode(union node *n) { union node *new; if (n == NULL) return NULL; new = funcblock; funcblock = (char *) funcblock + nodesize[n->type]; switch (n->type) { case NCMD: new->ncmd.redirect = copynode(n->ncmd.redirect); new->ncmd.args = copynode(n->ncmd.args); new->ncmd.assign = copynode(n->ncmd.assign); break; case NPIPE: new->npipe.cmdlist = copynodelist(n->npipe.cmdlist); new->npipe.pipe_backgnd = n->npipe.pipe_backgnd; break; case NREDIR: case NBACKGND: case NSUBSHELL: new->nredir.redirect = copynode(n->nredir.redirect); new->nredir.n = copynode(n->nredir.n); break; case NAND: case NOR: case NSEMI: case NWHILE: case NUNTIL: new->nbinary.ch2 = copynode(n->nbinary.ch2); new->nbinary.ch1 = copynode(n->nbinary.ch1); break; case NIF: new->nif.elsepart = copynode(n->nif.elsepart); new->nif.ifpart = copynode(n->nif.ifpart); new->nif.test = copynode(n->nif.test); break; case NFOR: new->nfor.var = nodeckstrdup(n->nfor.var); new->nfor.body = copynode(n->nfor.body); new->nfor.args = copynode(n->nfor.args); break; case NCASE: new->ncase.cases = copynode(n->ncase.cases); new->ncase.expr = copynode(n->ncase.expr); break; case NCLIST: new->nclist.body = copynode(n->nclist.body); new->nclist.pattern = copynode(n->nclist.pattern); new->nclist.next = copynode(n->nclist.next); break; case NDEFUN: case NARG: new->narg.backquote = copynodelist(n->narg.backquote); new->narg.text = nodeckstrdup(n->narg.text); new->narg.next = copynode(n->narg.next); break; case NTO: #if BASH_REDIR_OUTPUT case NTO2: #endif case NCLOBBER: case NFROM: case NFROMTO: case NAPPEND: new->nfile.fname = copynode(n->nfile.fname); new->nfile.fd = n->nfile.fd; new->nfile.next = copynode(n->nfile.next); break; case NTOFD: case NFROMFD: new->ndup.vname = copynode(n->ndup.vname); new->ndup.dupfd = n->ndup.dupfd; new->ndup.fd = n->ndup.fd; new->ndup.next = copynode(n->ndup.next); break; case NHERE: case NXHERE: new->nhere.doc = copynode(n->nhere.doc); new->nhere.fd = n->nhere.fd; new->nhere.next = copynode(n->nhere.next); break; case NNOT: new->nnot.com = copynode(n->nnot.com); break; }; new->type = n->type; return new; } /* * Make a copy of a parse tree. */ static struct funcnode * copyfunc(union node *n) { struct funcnode *f; size_t blocksize; /*funcstringsize = 0;*/ blocksize = offsetof(struct funcnode, n) + calcsize(0, n); f = ckzalloc(blocksize /* + funcstringsize */); funcblock = (char *) f + offsetof(struct funcnode, n); funcstring_end = (char *) f + blocksize; copynode(n); /* f->count = 0; - ckzalloc did it */ return f; } /* * Define a shell function. */ static void defun(union node *func) { struct cmdentry entry; INT_OFF; entry.cmdtype = CMDFUNCTION; entry.u.func = copyfunc(func); addcmdentry(func->narg.text, &entry); INT_ON; } /* Reasons for skipping commands (see comment on breakcmd routine) */ #define SKIPBREAK (1 << 0) #define SKIPCONT (1 << 1) #define SKIPFUNC (1 << 2) static smallint evalskip; /* set to SKIPxxx if we are skipping commands */ static int skipcount; /* number of levels to skip */ static int funcnest; /* depth of function calls */ static int loopnest; /* current loop nesting level */ /* Forward decl way out to parsing code - dotrap needs it */ static int evalstring(char *s, int flags); /* Called to execute a trap. * Single callsite - at the end of evaltree(). * If we return non-zero, evaltree raises EXEXIT exception. * * Perhaps we should avoid entering new trap handlers * while we are executing a trap handler. [is it a TODO?] */ static void dotrap(void) { uint8_t *g; int sig; uint8_t last_status; if (!pending_sig) return; last_status = exitstatus; pending_sig = 0; barrier(); TRACE(("dotrap entered\n")); for (sig = 1, g = gotsig; sig < NSIG; sig++, g++) { char *p; if (!*g) continue; if (evalskip) { pending_sig = sig; break; } p = trap[sig]; /* non-trapped SIGINT is handled separately by raise_interrupt, * don't upset it by resetting gotsig[SIGINT-1] */ if (sig == SIGINT && !p) continue; TRACE(("sig %d is active, will run handler '%s'\n", sig, p)); *g = 0; if (!p) continue; evalstring(p, 0); } exitstatus = last_status; TRACE(("dotrap returns\n")); } /* forward declarations - evaluation is fairly recursive business... */ static int evalloop(union node *, int); static int evalfor(union node *, int); static int evalcase(union node *, int); static int evalsubshell(union node *, int); static void expredir(union node *); static int evalpipe(union node *, int); static int evalcommand(union node *, int); static int evalbltin(const struct builtincmd *, int, char **, int); static void prehash(union node *); /* * Evaluate a parse tree. The value is left in the global variable * exitstatus. */ static int evaltree(union node *n, int flags) { int checkexit = 0; int (*evalfn)(union node *, int); int status = 0; if (n == NULL) { TRACE(("evaltree(NULL) called\n")); goto out; } TRACE(("evaltree(%p: %d, %d) called\n", n, n->type, flags)); dotrap(); switch (n->type) { default: #if DEBUG out1fmt("Node type = %d\n", n->type); fflush_all(); break; #endif case NNOT: status = !evaltree(n->nnot.com, EV_TESTED); goto setstatus; case NREDIR: expredir(n->nredir.redirect); status = redirectsafe(n->nredir.redirect, REDIR_PUSH); if (!status) { status = evaltree(n->nredir.n, flags & EV_TESTED); } if (n->nredir.redirect) popredir(/*drop:*/ 0, /*restore:*/ 0 /* not sure */); goto setstatus; case NCMD: evalfn = evalcommand; checkexit: if (eflag && !(flags & EV_TESTED)) checkexit = ~0; goto calleval; case NFOR: evalfn = evalfor; goto calleval; case NWHILE: case NUNTIL: evalfn = evalloop; goto calleval; case NSUBSHELL: case NBACKGND: evalfn = evalsubshell; goto checkexit; case NPIPE: evalfn = evalpipe; goto checkexit; case NCASE: evalfn = evalcase; goto calleval; case NAND: case NOR: case NSEMI: { #if NAND + 1 != NOR #error NAND + 1 != NOR #endif #if NOR + 1 != NSEMI #error NOR + 1 != NSEMI #endif unsigned is_or = n->type - NAND; status = evaltree( n->nbinary.ch1, (flags | ((is_or >> 1) - 1)) & EV_TESTED ); if ((!status) == is_or || evalskip) break; n = n->nbinary.ch2; evaln: evalfn = evaltree; calleval: status = evalfn(n, flags); goto setstatus; } case NIF: status = evaltree(n->nif.test, EV_TESTED); if (evalskip) break; if (!status) { n = n->nif.ifpart; goto evaln; } if (n->nif.elsepart) { n = n->nif.elsepart; goto evaln; } status = 0; goto setstatus; case NDEFUN: defun(n); /* Not necessary. To test it: * "false; f() { qwerty; }; echo $?" should print 0. */ /* status = 0; */ setstatus: exitstatus = status; break; } out: /* Order of checks below is important: * signal handlers trigger before exit caused by "set -e". */ dotrap(); if (checkexit & status) raise_exception(EXEXIT); if (flags & EV_EXIT) raise_exception(EXEXIT); TRACE(("leaving evaltree (no interrupts)\n")); return exitstatus; } #if !defined(__alpha__) || (defined(__GNUC__) && __GNUC__ >= 3) static #endif int evaltreenr(union node *, int) __attribute__ ((alias("evaltree"),__noreturn__)); static int skiploop(void) { int skip = evalskip; switch (skip) { case 0: break; case SKIPBREAK: case SKIPCONT: if (--skipcount <= 0) { evalskip = 0; break; } skip = SKIPBREAK; break; } return skip; } static int evalloop(union node *n, int flags) { int skip; int status; loopnest++; status = 0; flags &= EV_TESTED; do { int i; i = evaltree(n->nbinary.ch1, EV_TESTED); skip = skiploop(); if (skip == SKIPFUNC) status = i; if (skip) continue; if (n->type != NWHILE) i = !i; if (i != 0) break; status = evaltree(n->nbinary.ch2, flags); skip = skiploop(); } while (!(skip & ~SKIPCONT)); loopnest--; return status; } static int evalfor(union node *n, int flags) { struct arglist arglist; union node *argp; struct strlist *sp; struct stackmark smark; int status = 0; setstackmark(&smark); arglist.list = NULL; arglist.lastp = &arglist.list; for (argp = n->nfor.args; argp; argp = argp->narg.next) { expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); } *arglist.lastp = NULL; loopnest++; flags &= EV_TESTED; for (sp = arglist.list; sp; sp = sp->next) { setvar0(n->nfor.var, sp->text); status = evaltree(n->nfor.body, flags); if (skiploop() & ~SKIPCONT) break; } loopnest--; popstackmark(&smark); return status; } static int evalcase(union node *n, int flags) { union node *cp; union node *patp; struct arglist arglist; struct stackmark smark; int status = 0; setstackmark(&smark); arglist.list = NULL; arglist.lastp = &arglist.list; expandarg(n->ncase.expr, &arglist, EXP_TILDE); for (cp = n->ncase.cases; cp && evalskip == 0; cp = cp->nclist.next) { for (patp = cp->nclist.pattern; patp; patp = patp->narg.next) { if (casematch(patp, arglist.list->text)) { /* Ensure body is non-empty as otherwise * EV_EXIT may prevent us from setting the * exit status. */ if (evalskip == 0 && cp->nclist.body) { status = evaltree(cp->nclist.body, flags); } goto out; } } } out: popstackmark(&smark); return status; } /* * Kick off a subshell to evaluate a tree. */ static int evalsubshell(union node *n, int flags) { struct job *jp; int backgnd = (n->type == NBACKGND); /* FORK_BG(1) if yes, else FORK_FG(0) */ int status; expredir(n->nredir.redirect); if (!backgnd && (flags & EV_EXIT) && !may_have_traps) goto nofork; INT_OFF; if (backgnd == FORK_FG) get_tty_state(); jp = makejob(/*n,*/ 1); if (forkshell(jp, n, backgnd) == 0) { /* child */ INT_ON; flags |= EV_EXIT; if (backgnd) flags &= ~EV_TESTED; nofork: redirect(n->nredir.redirect, 0); evaltreenr(n->nredir.n, flags); /* never returns */ } /* parent */ status = 0; if (backgnd == FORK_FG) status = waitforjob(jp); INT_ON; return status; } /* * Compute the names of the files in a redirection list. */ static void fixredir(union node *, const char *, int); static void expredir(union node *n) { union node *redir; for (redir = n; redir; redir = redir->nfile.next) { struct arglist fn; fn.list = NULL; fn.lastp = &fn.list; switch (redir->type) { case NFROMTO: case NFROM: case NTO: #if BASH_REDIR_OUTPUT case NTO2: #endif case NCLOBBER: case NAPPEND: expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); TRACE(("expredir expanded to '%s'\n", fn.list->text)); #if BASH_REDIR_OUTPUT store_expfname: #endif #if 0 // By the design of stack allocator, the loop of this kind: // while true; do while true; do break; done nfile.expfname) stunalloc(redir->nfile.expfname); // It results in corrupted state of stacked allocations. #endif redir->nfile.expfname = fn.list->text; break; case NFROMFD: case NTOFD: /* >& */ if (redir->ndup.vname) { expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE); if (fn.list == NULL) ash_msg_and_raise_error("redir error"); #if BASH_REDIR_OUTPUT //FIXME: we used expandarg with different args! if (!isdigit_str9(fn.list->text)) { /* >&file, not >&fd */ if (redir->nfile.fd != 1) /* 123>&file - BAD */ ash_msg_and_raise_error("redir error"); redir->type = NTO2; goto store_expfname; } #endif fixredir(redir, fn.list->text, 1); } break; } } } /* * Evaluate a pipeline. All the processes in the pipeline are children * of the process creating the pipeline. (This differs from some versions * of the shell, which make the last process in a pipeline the parent * of all the rest.) */ static int evalpipe(union node *n, int flags) { struct job *jp; struct nodelist *lp; int pipelen; int prevfd; int pip[2]; int status = 0; TRACE(("evalpipe(0x%lx) called\n", (long)n)); pipelen = 0; for (lp = n->npipe.cmdlist; lp; lp = lp->next) pipelen++; flags |= EV_EXIT; INT_OFF; if (n->npipe.pipe_backgnd == 0) get_tty_state(); jp = makejob(/*n,*/ pipelen); prevfd = -1; for (lp = n->npipe.cmdlist; lp; lp = lp->next) { prehash(lp->n); pip[1] = -1; if (lp->next) { if (pipe(pip) < 0) { close(prevfd); ash_msg_and_raise_error("pipe call failed"); } } if (forkshell(jp, lp->n, n->npipe.pipe_backgnd) == 0) { /* child */ INT_ON; if (pip[1] >= 0) { close(pip[0]); } if (prevfd > 0) { dup2(prevfd, 0); close(prevfd); } if (pip[1] > 1) { dup2(pip[1], 1); close(pip[1]); } evaltreenr(lp->n, flags); /* never returns */ } /* parent */ if (prevfd >= 0) close(prevfd); prevfd = pip[0]; /* Don't want to trigger debugging */ if (pip[1] != -1) close(pip[1]); } if (n->npipe.pipe_backgnd == 0) { status = waitforjob(jp); TRACE(("evalpipe: job done exit status %d\n", status)); } INT_ON; return status; } /* * Controls whether the shell is interactive or not. */ static void setinteractive(int on) { static smallint is_interactive; if (++on == is_interactive) return; is_interactive = on; setsignal(SIGINT); setsignal(SIGQUIT); setsignal(SIGTERM); #if !ENABLE_FEATURE_SH_EXTRA_QUIET if (is_interactive > 1) { /* Looks like they want an interactive shell */ static smallint did_banner; if (!did_banner) { /* note: ash and hush share this string */ out1fmt("\n\n%s %s\n" IF_ASH_HELP("Enter 'help' for a list of built-in commands.\n") "\n", bb_banner, "built-in shell (ash)" ); did_banner = 1; } } #endif } static void optschanged(void) { #if DEBUG opentrace(); #endif setinteractive(iflag); setjobctl(mflag); #if ENABLE_FEATURE_EDITING_VI if (viflag) line_input_state->flags |= VI_MODE; else line_input_state->flags &= ~VI_MODE; #else viflag = 0; /* forcibly keep the option off */ #endif } static struct localvar *localvars; /* * Called after a function returns. * Interrupts must be off. */ static void poplocalvars(void) { struct localvar *lvp; struct var *vp; while ((lvp = localvars) != NULL) { localvars = lvp->next; vp = lvp->vp; TRACE(("poplocalvar %s\n", vp ? vp->var_text : "-")); if (vp == NULL) { /* $- saved */ memcpy(optlist, lvp->text, sizeof(optlist)); free((char*)lvp->text); optschanged(); } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) { unsetvar(vp->var_text); } else { if (vp->var_func) vp->var_func(var_end(lvp->text)); if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0) free((char*)vp->var_text); vp->flags = lvp->flags; vp->var_text = lvp->text; } free(lvp); } } static int evalfun(struct funcnode *func, int argc, char **argv, int flags) { volatile struct shparam saveparam; struct localvar *volatile savelocalvars; struct jmploc *volatile savehandler; struct jmploc jmploc; int e; saveparam = shellparam; savelocalvars = localvars; savehandler = exception_handler; e = setjmp(jmploc.loc); if (e) { goto funcdone; } INT_OFF; exception_handler = &jmploc; localvars = NULL; shellparam.malloced = 0; func->count++; funcnest++; INT_ON; shellparam.nparam = argc - 1; shellparam.p = argv + 1; #if ENABLE_ASH_GETOPTS shellparam.optind = 1; shellparam.optoff = -1; #endif evaltree(func->n.narg.next, flags & EV_TESTED); funcdone: INT_OFF; funcnest--; freefunc(func); poplocalvars(); localvars = savelocalvars; freeparam(&shellparam); shellparam = saveparam; exception_handler = savehandler; INT_ON; evalskip &= ~SKIPFUNC; return e; } /* * Make a variable a local variable. When a variable is made local, it's * value and flags are saved in a localvar structure. The saved values * will be restored when the shell function returns. We handle the name * "-" as a special case: it makes changes to "set +-options" local * (options will be restored on return from the function). */ static void mklocal(char *name) { struct localvar *lvp; struct var **vpp; struct var *vp; char *eq = strchr(name, '='); INT_OFF; /* Cater for duplicate "local". Examples: * x=0; f() { local x=1; echo $x; local x; echo $x; }; f; echo $x * x=0; f() { local x=1; echo $x; local x=2; echo $x; }; f; echo $x */ lvp = localvars; while (lvp) { if (lvp->vp && varcmp(lvp->vp->var_text, name) == 0) { if (eq) setvareq(name, 0); /* else: * it's a duplicate "local VAR" declaration, do nothing */ goto ret; } lvp = lvp->next; } lvp = ckzalloc(sizeof(*lvp)); if (LONE_DASH(name)) { char *p; p = ckmalloc(sizeof(optlist)); lvp->text = memcpy(p, optlist, sizeof(optlist)); vp = NULL; } else { vpp = hashvar(name); vp = *findvar(vpp, name); if (vp == NULL) { /* variable did not exist yet */ if (eq) setvareq(name, VSTRFIXED); else setvar(name, NULL, VSTRFIXED); vp = *vpp; /* the new variable */ lvp->flags = VUNSET; } else { lvp->text = vp->var_text; lvp->flags = vp->flags; /* make sure neither "struct var" nor string gets freed * during (un)setting: */ vp->flags |= VSTRFIXED|VTEXTFIXED; if (eq) setvareq(name, 0); else /* "local VAR" unsets VAR: */ setvar0(name, NULL); } } lvp->vp = vp; lvp->next = localvars; localvars = lvp; ret: INT_ON; } /* * The "local" command. */ static int FAST_FUNC localcmd(int argc UNUSED_PARAM, char **argv) { char *name; if (!funcnest) ash_msg_and_raise_error("not in a function"); argv = argptr; while ((name = *argv++) != NULL) { mklocal(name); } return 0; } static int FAST_FUNC falsecmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { return 1; } static int FAST_FUNC truecmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { return 0; } static int FAST_FUNC execcmd(int argc UNUSED_PARAM, char **argv) { optionarg = NULL; while (nextopt("a:") != '\0') /* nextopt() sets optionarg to "-a ARGV0" */; argv = argptr; if (argv[0]) { char *prog; iflag = 0; /* exit on error */ mflag = 0; optschanged(); /* We should set up signals for "exec CMD" * the same way as for "CMD" without "exec". * But optschanged->setinteractive->setsignal * still thought we are a root shell. Therefore, for example, * SIGQUIT is still set to IGN. Fix it: */ shlvl++; setsignal(SIGQUIT); /*setsignal(SIGTERM); - unnecessary because of iflag=0 */ /*setsignal(SIGTSTP); - unnecessary because of mflag=0 */ /*setsignal(SIGTTOU); - unnecessary because of mflag=0 */ prog = argv[0]; if (optionarg) argv[0] = optionarg; shellexec(prog, argv, pathval(), 0); /* NOTREACHED */ } return 0; } /* * The return command. */ static int FAST_FUNC returncmd(int argc UNUSED_PARAM, char **argv) { /* * If called outside a function, do what ksh does; * skip the rest of the file. */ evalskip = SKIPFUNC; return argv[1] ? number(argv[1]) : exitstatus; } /* Forward declarations for builtintab[] */ static int breakcmd(int, char **) FAST_FUNC; static int dotcmd(int, char **) FAST_FUNC; static int evalcmd(int, char **, int) FAST_FUNC; static int exitcmd(int, char **) FAST_FUNC; static int exportcmd(int, char **) FAST_FUNC; #if ENABLE_ASH_GETOPTS static int getoptscmd(int, char **) FAST_FUNC; #endif #if ENABLE_ASH_HELP static int helpcmd(int, char **) FAST_FUNC; #endif #if MAX_HISTORY static int historycmd(int, char **) FAST_FUNC; #endif #if ENABLE_FEATURE_SH_MATH static int letcmd(int, char **) FAST_FUNC; #endif static int readcmd(int, char **) FAST_FUNC; static int setcmd(int, char **) FAST_FUNC; static int shiftcmd(int, char **) FAST_FUNC; static int timescmd(int, char **) FAST_FUNC; static int trapcmd(int, char **) FAST_FUNC; static int umaskcmd(int, char **) FAST_FUNC; static int unsetcmd(int, char **) FAST_FUNC; static int ulimitcmd(int, char **) FAST_FUNC; #define BUILTIN_NOSPEC "0" #define BUILTIN_SPECIAL "1" #define BUILTIN_REGULAR "2" #define BUILTIN_SPEC_REG "3" #define BUILTIN_ASSIGN "4" #define BUILTIN_SPEC_ASSG "5" #define BUILTIN_REG_ASSG "6" #define BUILTIN_SPEC_REG_ASSG "7" /* Stubs for calling non-FAST_FUNC's */ #if ENABLE_ASH_ECHO static int FAST_FUNC echocmd(int argc, char **argv) { return echo_main(argc, argv); } #endif #if ENABLE_ASH_PRINTF static int FAST_FUNC printfcmd(int argc, char **argv) { return printf_main(argc, argv); } #endif #if ENABLE_ASH_TEST || BASH_TEST2 static int FAST_FUNC testcmd(int argc, char **argv) { return test_main(argc, argv); } #endif /* Keep these in proper order since it is searched via bsearch() */ static const struct builtincmd builtintab[] = { { BUILTIN_SPEC_REG "." , dotcmd }, { BUILTIN_SPEC_REG ":" , truecmd }, #if ENABLE_ASH_TEST { BUILTIN_REGULAR "[" , testcmd }, #endif #if BASH_TEST2 { BUILTIN_REGULAR "[[" , testcmd }, #endif #if ENABLE_ASH_ALIAS { BUILTIN_REG_ASSG "alias" , aliascmd }, #endif #if JOBS { BUILTIN_REGULAR "bg" , fg_bgcmd }, #endif { BUILTIN_SPEC_REG "break" , breakcmd }, { BUILTIN_REGULAR "cd" , cdcmd }, { BUILTIN_NOSPEC "chdir" , cdcmd }, #if ENABLE_ASH_CMDCMD { BUILTIN_REGULAR "command" , commandcmd }, #endif { BUILTIN_SPEC_REG "continue", breakcmd }, #if ENABLE_ASH_ECHO { BUILTIN_REGULAR "echo" , echocmd }, #endif { BUILTIN_SPEC_REG "eval" , NULL }, /*evalcmd() has a differing prototype*/ { BUILTIN_SPEC_REG "exec" , execcmd }, { BUILTIN_SPEC_REG "exit" , exitcmd }, { BUILTIN_SPEC_REG_ASSG "export" , exportcmd }, { BUILTIN_REGULAR "false" , falsecmd }, #if JOBS { BUILTIN_REGULAR "fg" , fg_bgcmd }, #endif #if ENABLE_ASH_GETOPTS { BUILTIN_REGULAR "getopts" , getoptscmd }, #endif { BUILTIN_NOSPEC "hash" , hashcmd }, #if ENABLE_ASH_HELP { BUILTIN_NOSPEC "help" , helpcmd }, #endif #if MAX_HISTORY { BUILTIN_NOSPEC "history" , historycmd }, #endif #if JOBS { BUILTIN_REGULAR "jobs" , jobscmd }, { BUILTIN_REGULAR "kill" , killcmd }, #endif #if ENABLE_FEATURE_SH_MATH { BUILTIN_NOSPEC "let" , letcmd }, #endif { BUILTIN_ASSIGN "local" , localcmd }, #if ENABLE_ASH_PRINTF { BUILTIN_REGULAR "printf" , printfcmd }, #endif { BUILTIN_NOSPEC "pwd" , pwdcmd }, { BUILTIN_REGULAR "read" , readcmd }, { BUILTIN_SPEC_REG_ASSG "readonly", exportcmd }, { BUILTIN_SPEC_REG "return" , returncmd }, { BUILTIN_SPEC_REG "set" , setcmd }, { BUILTIN_SPEC_REG "shift" , shiftcmd }, #if BASH_SOURCE { BUILTIN_SPEC_REG "source" , dotcmd }, #endif #if ENABLE_ASH_TEST { BUILTIN_REGULAR "test" , testcmd }, #endif { BUILTIN_SPEC_REG "times" , timescmd }, { BUILTIN_SPEC_REG "trap" , trapcmd }, { BUILTIN_REGULAR "true" , truecmd }, { BUILTIN_NOSPEC "type" , typecmd }, { BUILTIN_NOSPEC "ulimit" , ulimitcmd }, { BUILTIN_REGULAR "umask" , umaskcmd }, #if ENABLE_ASH_ALIAS { BUILTIN_REGULAR "unalias" , unaliascmd }, #endif { BUILTIN_SPEC_REG "unset" , unsetcmd }, { BUILTIN_REGULAR "wait" , waitcmd }, }; /* Should match the above table! */ #define COMMANDCMD (builtintab + \ /* . : */ 2 + \ /* [ */ 1 * ENABLE_ASH_TEST + \ /* [[ */ 1 * BASH_TEST2 + \ /* alias */ 1 * ENABLE_ASH_ALIAS + \ /* bg */ 1 * ENABLE_ASH_JOB_CONTROL + \ /* break cd cddir */ 3) #define EVALCMD (COMMANDCMD + \ /* command */ 1 * ENABLE_ASH_CMDCMD + \ /* continue */ 1 + \ /* echo */ 1 * ENABLE_ASH_ECHO + \ 0) #define EXECCMD (EVALCMD + \ /* eval */ 1) /* * Search the table of builtin commands. */ static int pstrcmp1(const void *a, const void *b) { return strcmp((char*)a, *(char**)b + 1); } static struct builtincmd * find_builtin(const char *name) { struct builtincmd *bp; bp = bsearch( name, builtintab, ARRAY_SIZE(builtintab), sizeof(builtintab[0]), pstrcmp1 ); return bp; } /* * Execute a simple command. */ static int isassignment(const char *p) { const char *q = endofname(p); if (p == q) return 0; return *q == '='; } static int FAST_FUNC bltincmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { /* Preserve exitstatus of a previous possible redirection * as POSIX mandates */ return back_exitstatus; } static int evalcommand(union node *cmd, int flags) { static const struct builtincmd null_bltin = { "\0\0", bltincmd /* why three NULs? */ }; struct stackmark smark; union node *argp; struct arglist arglist; struct arglist varlist; char **argv; int argc; const struct strlist *sp; struct cmdentry cmdentry; struct job *jp; char *lastarg; const char *path; int spclbltin; int status; char **nargv; struct builtincmd *bcmd; smallint cmd_is_exec; smallint pseudovarflag = 0; /* First expand the arguments. */ TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags)); setstackmark(&smark); back_exitstatus = 0; cmdentry.cmdtype = CMDBUILTIN; cmdentry.u.cmd = &null_bltin; varlist.lastp = &varlist.list; *varlist.lastp = NULL; arglist.lastp = &arglist.list; *arglist.lastp = NULL; argc = 0; if (cmd->ncmd.args) { bcmd = find_builtin(cmd->ncmd.args->narg.text); pseudovarflag = bcmd && IS_BUILTIN_ASSIGN(bcmd); } for (argp = cmd->ncmd.args; argp; argp = argp->narg.next) { struct strlist **spp; spp = arglist.lastp; if (pseudovarflag && isassignment(argp->narg.text)) expandarg(argp, &arglist, EXP_VARTILDE); else expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); for (sp = *spp; sp; sp = sp->next) argc++; } /* Reserve one extra spot at the front for shellexec. */ nargv = stalloc(sizeof(char *) * (argc + 2)); argv = ++nargv; for (sp = arglist.list; sp; sp = sp->next) { TRACE(("evalcommand arg: %s\n", sp->text)); *nargv++ = sp->text; } *nargv = NULL; lastarg = NULL; if (iflag && funcnest == 0 && argc > 0) lastarg = nargv[-1]; preverrout_fd = 2; expredir(cmd->ncmd.redirect); status = redirectsafe(cmd->ncmd.redirect, REDIR_PUSH | REDIR_SAVEFD2); path = vpath.var_text; for (argp = cmd->ncmd.assign; argp; argp = argp->narg.next) { struct strlist **spp; char *p; spp = varlist.lastp; expandarg(argp, &varlist, EXP_VARTILDE); /* * Modify the command lookup path, if a PATH= assignment * is present */ p = (*spp)->text; if (varcmp(p, path) == 0) path = p; } /* Print the command if xflag is set. */ if (xflag) { int n; const char *p = " %s" + 1; fdprintf(preverrout_fd, p, expandstr(ps4val())); sp = varlist.list; for (n = 0; n < 2; n++) { while (sp) { fdprintf(preverrout_fd, p, sp->text); sp = sp->next; p = " %s"; } sp = arglist.list; } safe_write(preverrout_fd, "\n", 1); } cmd_is_exec = 0; spclbltin = -1; /* Now locate the command. */ if (argc) { int cmd_flag = DO_ERR; #if ENABLE_ASH_CMDCMD const char *oldpath = path + 5; #endif path += 5; for (;;) { find_command(argv[0], &cmdentry, cmd_flag, path); if (cmdentry.cmdtype == CMDUNKNOWN) { flush_stdout_stderr(); status = 127; goto bail; } /* implement bltin and command here */ if (cmdentry.cmdtype != CMDBUILTIN) break; if (spclbltin < 0) spclbltin = IS_BUILTIN_SPECIAL(cmdentry.u.cmd); if (cmdentry.u.cmd == EXECCMD) cmd_is_exec = 1; #if ENABLE_ASH_CMDCMD if (cmdentry.u.cmd == COMMANDCMD) { path = oldpath; nargv = parse_command_args(argv, &path); if (!nargv) break; /* It's "command [-p] PROG ARGS" (that is, no -Vv). * nargv => "PROG". path is updated if -p. */ argc -= nargv - argv; argv = nargv; cmd_flag |= DO_NOFUNC; } else #endif break; } } if (status) { bail: exitstatus = status; /* We have a redirection error. */ if (spclbltin > 0) raise_exception(EXERROR); goto out; } /* Execute the command. */ switch (cmdentry.cmdtype) { default: { #if ENABLE_FEATURE_SH_NOFORK /* (1) BUG: if variables are set, we need to fork, or save/restore them * around run_nofork_applet() call. * (2) Should this check also be done in forkshell()? * (perhaps it should, so that "VAR=VAL nofork" at least avoids exec...) */ /* find_command() encodes applet_no as (-2 - applet_no) */ int applet_no = (- cmdentry.u.index - 2); if (applet_no >= 0 && APPLET_IS_NOFORK(applet_no)) { listsetvar(varlist.list, VEXPORT|VSTACK); /* run _main() */ status = run_nofork_applet(applet_no, argv); break; } #endif /* Can we avoid forking off? For example, very last command * in a script or a subshell does not need forking, * we can just exec it. */ if (!(flags & EV_EXIT) || may_have_traps) { /* No, forking off a child is necessary */ INT_OFF; get_tty_state(); jp = makejob(/*cmd,*/ 1); if (forkshell(jp, cmd, FORK_FG) != 0) { /* parent */ status = waitforjob(jp); INT_ON; TRACE(("forked child exited with %d\n", status)); break; } /* child */ FORCE_INT_ON; /* fall through to exec'ing external program */ } listsetvar(varlist.list, VEXPORT|VSTACK); shellexec(argv[0], argv, path, cmdentry.u.index); /* NOTREACHED */ } /* default */ case CMDBUILTIN: cmdenviron = varlist.list; if (cmdenviron) { struct strlist *list = cmdenviron; int i = VNOSET; if (spclbltin > 0 || argc == 0) { i = 0; if (cmd_is_exec && argc > 1) i = VEXPORT; } listsetvar(list, i); } /* Tight loop with builtins only: * "while kill -0 $child; do true; done" * will never exit even if $child died, unless we do this * to reap the zombie and make kill detect that it's gone: */ dowait(DOWAIT_NONBLOCK, NULL); if (evalbltin(cmdentry.u.cmd, argc, argv, flags)) { if (exception_type == EXERROR && spclbltin <= 0) { FORCE_INT_ON; goto readstatus; } raise: longjmp(exception_handler->loc, 1); } goto readstatus; case CMDFUNCTION: listsetvar(varlist.list, 0); /* See above for the rationale */ dowait(DOWAIT_NONBLOCK, NULL); if (evalfun(cmdentry.u.func, argc, argv, flags)) goto raise; readstatus: status = exitstatus; break; } /* switch */ out: if (cmd->ncmd.redirect) popredir(/*drop:*/ cmd_is_exec, /*restore:*/ cmd_is_exec); if (lastarg) { /* dsl: I think this is intended to be used to support * '_' in 'vi' command mode during line editing... * However I implemented that within libedit itself. */ setvar0("_", lastarg); } popstackmark(&smark); return status; } static int evalbltin(const struct builtincmd *cmd, int argc, char **argv, int flags) { char *volatile savecmdname; struct jmploc *volatile savehandler; struct jmploc jmploc; int status; int i; savecmdname = commandname; savehandler = exception_handler; i = setjmp(jmploc.loc); if (i) goto cmddone; exception_handler = &jmploc; commandname = argv[0]; argptr = argv + 1; optptr = NULL; /* initialize nextopt */ if (cmd == EVALCMD) status = evalcmd(argc, argv, flags); else status = (*cmd->builtin)(argc, argv); flush_stdout_stderr(); status |= ferror(stdout); exitstatus = status; cmddone: clearerr(stdout); commandname = savecmdname; exception_handler = savehandler; return i; } static int goodname(const char *p) { return endofname(p)[0] == '\0'; } /* * Search for a command. This is called before we fork so that the * location of the command will be available in the parent as well as * the child. The check for "goodname" is an overly conservative * check that the name will not be subject to expansion. */ static void prehash(union node *n) { struct cmdentry entry; if (n->type == NCMD && n->ncmd.args && goodname(n->ncmd.args->narg.text)) find_command(n->ncmd.args->narg.text, &entry, 0, pathval()); } /* ============ Builtin commands * * Builtin commands whose functions are closely tied to evaluation * are implemented here. */ /* * Handle break and continue commands. Break, continue, and return are * all handled by setting the evalskip flag. The evaluation routines * above all check this flag, and if it is set they start skipping * commands rather than executing them. The variable skipcount is * the number of loops to break/continue, or the number of function * levels to return. (The latter is always 1.) It should probably * be an error to break out of more loops than exist, but it isn't * in the standard shell so we don't make it one here. */ static int FAST_FUNC breakcmd(int argc UNUSED_PARAM, char **argv) { int n = argv[1] ? number(argv[1]) : 1; if (n <= 0) ash_msg_and_raise_error(msg_illnum, argv[1]); if (n > loopnest) n = loopnest; if (n > 0) { evalskip = (**argv == 'c') ? SKIPCONT : SKIPBREAK; skipcount = n; } return 0; } /* * This implements the input routines used by the parser. */ enum { INPUT_PUSH_FILE = 1, INPUT_NOFILE_OK = 2, }; static smallint checkkwd; /* values of checkkwd variable */ #define CHKALIAS 0x1 #define CHKKWD 0x2 #define CHKNL 0x4 /* * Push a string back onto the input at this current parsefile level. * We handle aliases this way. */ #if !ENABLE_ASH_ALIAS #define pushstring(s, ap) pushstring(s) #endif static void pushstring(char *s, struct alias *ap) { struct strpush *sp; int len; len = strlen(s); INT_OFF; if (g_parsefile->strpush) { sp = ckzalloc(sizeof(*sp)); sp->prev = g_parsefile->strpush; } else { sp = &(g_parsefile->basestrpush); } g_parsefile->strpush = sp; sp->prev_string = g_parsefile->next_to_pgetc; sp->prev_left_in_line = g_parsefile->left_in_line; sp->unget = g_parsefile->unget; memcpy(sp->lastc, g_parsefile->lastc, sizeof(sp->lastc)); #if ENABLE_ASH_ALIAS sp->ap = ap; if (ap) { ap->flag |= ALIASINUSE; sp->string = s; } #endif g_parsefile->next_to_pgetc = s; g_parsefile->left_in_line = len; g_parsefile->unget = 0; INT_ON; } static void popstring(void) { struct strpush *sp = g_parsefile->strpush; INT_OFF; #if ENABLE_ASH_ALIAS if (sp->ap) { if (g_parsefile->next_to_pgetc[-1] == ' ' || g_parsefile->next_to_pgetc[-1] == '\t' ) { checkkwd |= CHKALIAS; } if (sp->string != sp->ap->val) { free(sp->string); } sp->ap->flag &= ~ALIASINUSE; if (sp->ap->flag & ALIASDEAD) { unalias(sp->ap->name); } } #endif g_parsefile->next_to_pgetc = sp->prev_string; g_parsefile->left_in_line = sp->prev_left_in_line; g_parsefile->unget = sp->unget; memcpy(g_parsefile->lastc, sp->lastc, sizeof(sp->lastc)); g_parsefile->strpush = sp->prev; if (sp != &(g_parsefile->basestrpush)) free(sp); INT_ON; } static int preadfd(void) { int nr; char *buf = g_parsefile->buf; g_parsefile->next_to_pgetc = buf; #if ENABLE_FEATURE_EDITING retry: if (!iflag || g_parsefile->pf_fd != STDIN_FILENO) nr = nonblock_immune_read(g_parsefile->pf_fd, buf, IBUFSIZ - 1); else { int timeout = -1; # if ENABLE_ASH_IDLE_TIMEOUT if (iflag) { const char *tmout_var = lookupvar("TMOUT"); if (tmout_var) { timeout = atoi(tmout_var) * 1000; if (timeout <= 0) timeout = -1; } } # endif # if ENABLE_FEATURE_TAB_COMPLETION line_input_state->path_lookup = pathval(); # endif reinit_unicode_for_ash(); nr = read_line_input(line_input_state, cmdedit_prompt, buf, IBUFSIZ, timeout); if (nr == 0) { /* ^C pressed, "convert" to SIGINT */ write(STDOUT_FILENO, "^C", 2); if (trap[SIGINT]) { buf[0] = '\n'; buf[1] = '\0'; raise(SIGINT); return 1; } exitstatus = 128 + SIGINT; bb_putchar('\n'); goto retry; } if (nr < 0) { if (errno == 0) { /* Ctrl+D pressed */ nr = 0; } # if ENABLE_ASH_IDLE_TIMEOUT else if (errno == EAGAIN && timeout > 0) { puts("\007timed out waiting for input: auto-logout"); exitshell(); } # endif } } #else nr = nonblock_immune_read(g_parsefile->pf_fd, buf, IBUFSIZ - 1); #endif #if 0 /* disabled: nonblock_immune_read() handles this problem */ if (nr < 0) { if (parsefile->fd == 0 && errno == EWOULDBLOCK) { int flags = fcntl(0, F_GETFL); if (flags >= 0 && (flags & O_NONBLOCK)) { flags &= ~O_NONBLOCK; if (fcntl(0, F_SETFL, flags) >= 0) { out2str("sh: turning off NDELAY mode\n"); goto retry; } } } } #endif return nr; } /* * Refill the input buffer and return the next input character: * * 1) If a string was pushed back on the input, pop it; * 2) If an EOF was pushed back (g_parsefile->left_in_line < -BIGNUM) * or we are reading from a string so we can't refill the buffer, * return EOF. * 3) If there is more stuff in this buffer, use it else call read to fill it. * 4) Process input up to the next newline, deleting nul characters. */ //#define pgetc_debug(...) bb_error_msg(__VA_ARGS__) #define pgetc_debug(...) ((void)0) static int pgetc(void); static int preadbuffer(void) { char *q; int more; if (g_parsefile->strpush) { #if ENABLE_ASH_ALIAS if (g_parsefile->left_in_line == -1 && g_parsefile->strpush->ap && g_parsefile->next_to_pgetc[-1] != ' ' && g_parsefile->next_to_pgetc[-1] != '\t' ) { pgetc_debug("preadbuffer PEOA"); return PEOA; } #endif popstring(); return pgetc(); } /* on both branches above g_parsefile->left_in_line < 0. * "pgetc" needs refilling. */ /* -90 is our -BIGNUM. Below we use -99 to mark "EOF on read", * pungetc() may increment it a few times. * Assuming it won't increment it to less than -90. */ if (g_parsefile->left_in_line < -90 || g_parsefile->buf == NULL) { pgetc_debug("preadbuffer PEOF1"); /* even in failure keep left_in_line and next_to_pgetc * in lock step, for correct multi-layer pungetc. * left_in_line was decremented before preadbuffer(), * must inc next_to_pgetc: */ g_parsefile->next_to_pgetc++; return PEOF; } more = g_parsefile->left_in_buffer; if (more <= 0) { flush_stdout_stderr(); again: more = preadfd(); if (more <= 0) { /* don't try reading again */ g_parsefile->left_in_line = -99; pgetc_debug("preadbuffer PEOF2"); g_parsefile->next_to_pgetc++; return PEOF; } } /* Find out where's the end of line. * Set g_parsefile->left_in_line * and g_parsefile->left_in_buffer acordingly. * NUL chars are deleted. */ q = g_parsefile->next_to_pgetc; for (;;) { char c; more--; c = *q; if (c == '\0') { memmove(q, q + 1, more); } else { q++; if (c == '\n') { g_parsefile->left_in_line = q - g_parsefile->next_to_pgetc - 1; break; } } if (more <= 0) { g_parsefile->left_in_line = q - g_parsefile->next_to_pgetc - 1; if (g_parsefile->left_in_line < 0) goto again; break; } } g_parsefile->left_in_buffer = more; if (vflag) { char save = *q; *q = '\0'; out2str(g_parsefile->next_to_pgetc); *q = save; } pgetc_debug("preadbuffer at %d:%p'%s'", g_parsefile->left_in_line, g_parsefile->next_to_pgetc, g_parsefile->next_to_pgetc); return (unsigned char)*g_parsefile->next_to_pgetc++; } static void nlprompt(void) { g_parsefile->linno++; setprompt_if(doprompt, 2); } static void nlnoprompt(void) { g_parsefile->linno++; needprompt = doprompt; } static int pgetc(void) { int c; pgetc_debug("pgetc at %d:%p'%s'", g_parsefile->left_in_line, g_parsefile->next_to_pgetc, g_parsefile->next_to_pgetc); if (g_parsefile->unget) return g_parsefile->lastc[--g_parsefile->unget]; if (--g_parsefile->left_in_line >= 0) c = (unsigned char)*g_parsefile->next_to_pgetc++; else c = preadbuffer(); g_parsefile->lastc[1] = g_parsefile->lastc[0]; g_parsefile->lastc[0] = c; return c; } #if ENABLE_ASH_ALIAS static int pgetc_without_PEOA(void) { int c; do { pgetc_debug("pgetc at %d:%p'%s'", g_parsefile->left_in_line, g_parsefile->next_to_pgetc, g_parsefile->next_to_pgetc); c = pgetc(); } while (c == PEOA); return c; } #else # define pgetc_without_PEOA() pgetc() #endif /* * Read a line from the script. */ static char * pfgets(char *line, int len) { char *p = line; int nleft = len; int c; while (--nleft > 0) { c = pgetc_without_PEOA(); if (c == PEOF) { if (p == line) return NULL; break; } *p++ = c; if (c == '\n') break; } *p = '\0'; return line; } /* * Undo a call to pgetc. Only two characters may be pushed back. * PEOF may be pushed back. */ static void pungetc(void) { g_parsefile->unget++; } /* This one eats backslash+newline */ static int pgetc_eatbnl(void) { int c; while ((c = pgetc()) == '\\') { if (pgetc() != '\n') { pungetc(); break; } nlprompt(); } return c; } /* * To handle the "." command, a stack of input files is used. Pushfile * adds a new entry to the stack and popfile restores the previous level. */ static void pushfile(void) { struct parsefile *pf; pf = ckzalloc(sizeof(*pf)); pf->prev = g_parsefile; pf->pf_fd = -1; /*pf->strpush = NULL; - ckzalloc did it */ /*pf->basestrpush.prev = NULL;*/ /*pf->unget = 0;*/ g_parsefile = pf; } static void popfile(void) { struct parsefile *pf = g_parsefile; if (pf == &basepf) return; INT_OFF; if (pf->pf_fd >= 0) close(pf->pf_fd); free(pf->buf); while (pf->strpush) popstring(); g_parsefile = pf->prev; free(pf); INT_ON; } /* * Return to top level. */ static void popallfiles(void) { while (g_parsefile != &basepf) popfile(); } /* * Close the file(s) that the shell is reading commands from. Called * after a fork is done. */ static void closescript(void) { popallfiles(); if (g_parsefile->pf_fd > 0) { close(g_parsefile->pf_fd); g_parsefile->pf_fd = 0; } } /* * Like setinputfile, but takes an open file descriptor. Call this with * interrupts off. */ static void setinputfd(int fd, int push) { if (push) { pushfile(); g_parsefile->buf = NULL; } g_parsefile->pf_fd = fd; if (g_parsefile->buf == NULL) g_parsefile->buf = ckmalloc(IBUFSIZ); g_parsefile->left_in_buffer = 0; g_parsefile->left_in_line = 0; g_parsefile->linno = 1; } /* * Set the input to take input from a file. If push is set, push the * old input onto the stack first. */ static int setinputfile(const char *fname, int flags) { int fd; INT_OFF; fd = open(fname, O_RDONLY); if (fd < 0) { if (flags & INPUT_NOFILE_OK) goto out; exitstatus = 127; ash_msg_and_raise_error("can't open '%s'", fname); } if (fd < 10) fd = savefd(fd); else close_on_exec_on(fd); setinputfd(fd, flags & INPUT_PUSH_FILE); out: INT_ON; return fd; } /* * Like setinputfile, but takes input from a string. */ static void setinputstring(char *string) { INT_OFF; pushfile(); g_parsefile->next_to_pgetc = string; g_parsefile->left_in_line = strlen(string); g_parsefile->buf = NULL; g_parsefile->linno = 1; INT_ON; } /* * Routines to check for mail. */ #if ENABLE_ASH_MAIL /* Hash of mtimes of mailboxes */ static unsigned mailtime_hash; /* Set if MAIL or MAILPATH is changed. */ static smallint mail_var_path_changed; /* * Print appropriate message(s) if mail has arrived. * If mail_var_path_changed is set, * then the value of MAIL has mail_var_path_changed, * so we just update the values. */ static void chkmail(void) { const char *mpath; char *p; char *q; unsigned new_hash; struct stackmark smark; struct stat statb; setstackmark(&smark); mpath = mpathset() ? mpathval() : mailval(); new_hash = 0; for (;;) { p = path_advance(&mpath, nullstr); if (p == NULL) break; if (*p == '\0') continue; for (q = p; *q; q++) continue; #if DEBUG if (q[-1] != '/') abort(); #endif q[-1] = '\0'; /* delete trailing '/' */ if (stat(p, &statb) < 0) { continue; } /* Very simplistic "hash": just a sum of all mtimes */ new_hash += (unsigned)statb.st_mtime; } if (!mail_var_path_changed && mailtime_hash != new_hash) { if (mailtime_hash != 0) out2str("you have mail\n"); mailtime_hash = new_hash; } mail_var_path_changed = 0; popstackmark(&smark); } static void FAST_FUNC changemail(const char *val UNUSED_PARAM) { mail_var_path_changed = 1; } #endif /* ASH_MAIL */ /* ============ ??? */ /* * Set the shell parameters. */ static void setparam(char **argv) { char **newparam; char **ap; int nparam; for (nparam = 0; argv[nparam]; nparam++) continue; ap = newparam = ckmalloc((nparam + 1) * sizeof(*ap)); while (*argv) { *ap++ = ckstrdup(*argv++); } *ap = NULL; freeparam(&shellparam); shellparam.malloced = 1; shellparam.nparam = nparam; shellparam.p = newparam; #if ENABLE_ASH_GETOPTS shellparam.optind = 1; shellparam.optoff = -1; #endif } /* * Process shell options. The global variable argptr contains a pointer * to the argument list; we advance it past the options. * * SUSv3 section 2.8.1 "Consequences of Shell Errors" says: * For a non-interactive shell, an error condition encountered * by a special built-in ... shall cause the shell to write a diagnostic message * to standard error and exit as shown in the following table: * Error Special Built-In * ... * Utility syntax error (option or operand error) Shall exit * ... * However, in bug 1142 (http://busybox.net/bugs/view.php?id=1142) * we see that bash does not do that (set "finishes" with error code 1 instead, * and shell continues), and people rely on this behavior! * Testcase: * set -o barfoo 2>/dev/null * echo $? * * Oh well. Let's mimic that. */ static int plus_minus_o(char *name, int val) { int i; if (name) { for (i = 0; i < NOPTS; i++) { if (strcmp(name, optnames(i)) == 0) { optlist[i] = val; return 0; } } ash_msg("illegal option %co %s", val ? '-' : '+', name); return 1; } for (i = 0; i < NOPTS; i++) { if (val) { out1fmt("%-16s%s\n", optnames(i), optlist[i] ? "on" : "off"); } else { out1fmt("set %co %s\n", optlist[i] ? '-' : '+', optnames(i)); } } return 0; } static void setoption(int flag, int val) { int i; for (i = 0; i < NOPTS; i++) { if (optletters(i) == flag) { optlist[i] = val; return; } } ash_msg_and_raise_error("illegal option %c%c", val ? '-' : '+', flag); /* NOTREACHED */ } static int options(int cmdline) { char *p; int val; int c; if (cmdline) minusc = NULL; while ((p = *argptr) != NULL) { c = *p++; if (c != '-' && c != '+') break; argptr++; val = 0; /* val = 0 if c == '+' */ if (c == '-') { val = 1; if (p[0] == '\0' || LONE_DASH(p)) { if (!cmdline) { /* "-" means turn off -x and -v */ if (p[0] == '\0') xflag = vflag = 0; /* "--" means reset params */ else if (*argptr == NULL) setparam(argptr); } break; /* "-" or "--" terminates options */ } } /* first char was + or - */ while ((c = *p++) != '\0') { /* bash 3.2 indeed handles -c CMD and +c CMD the same */ if (c == 'c' && cmdline) { minusc = p; /* command is after shell args */ } else if (c == 'o') { if (plus_minus_o(*argptr, val)) { /* it already printed err message */ return 1; /* error */ } if (*argptr) argptr++; } else if (cmdline && (c == 'l')) { /* -l or +l == --login */ isloginsh = 1; /* bash does not accept +-login, we also won't */ } else if (cmdline && val && (c == '-')) { /* long options */ if (strcmp(p, "login") == 0) isloginsh = 1; break; } else { setoption(c, val); } } } return 0; } /* * The shift builtin command. */ static int FAST_FUNC shiftcmd(int argc UNUSED_PARAM, char **argv) { int n; char **ap1, **ap2; n = 1; if (argv[1]) n = number(argv[1]); if (n > shellparam.nparam) n = 0; /* bash compat, was = shellparam.nparam; */ INT_OFF; shellparam.nparam -= n; for (ap1 = shellparam.p; --n >= 0; ap1++) { if (shellparam.malloced) free(*ap1); } ap2 = shellparam.p; while ((*ap2++ = *ap1++) != NULL) continue; #if ENABLE_ASH_GETOPTS shellparam.optind = 1; shellparam.optoff = -1; #endif INT_ON; return 0; } /* * POSIX requires that 'set' (but not export or readonly) output the * variables in lexicographic order - by the locale's collating order (sigh). * Maybe we could keep them in an ordered balanced binary tree * instead of hashed lists. * For now just roll 'em through qsort for printing... */ static int showvars(const char *sep_prefix, int on, int off) { const char *sep; char **ep, **epend; ep = listvars(on, off, &epend); qsort(ep, epend - ep, sizeof(char *), vpcmp); sep = *sep_prefix ? " " : sep_prefix; for (; ep < epend; ep++) { const char *p; const char *q; p = strchrnul(*ep, '='); q = nullstr; if (*p) q = single_quote(++p); out1fmt("%s%s%.*s%s\n", sep_prefix, sep, (int)(p - *ep), *ep, q); } return 0; } /* * The set command builtin. */ static int FAST_FUNC setcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { int retval; if (!argv[1]) return showvars(nullstr, 0, VUNSET); INT_OFF; retval = options(/*cmdline:*/ 0); if (retval == 0) { /* if no parse error... */ optschanged(); if (*argptr != NULL) { setparam(argptr); } } INT_ON; return retval; } #if ENABLE_ASH_RANDOM_SUPPORT static void FAST_FUNC change_random(const char *value) { uint32_t t; if (value == NULL) { /* "get", generate */ t = next_random(&random_gen); /* set without recursion */ setvar(vrandom.var_text, utoa(t), VNOFUNC); vrandom.flags &= ~VNOFUNC; } else { /* set/reset */ t = strtoul(value, NULL, 10); INIT_RANDOM_T(&random_gen, (t ? t : 1), t); } } #endif #if ENABLE_ASH_GETOPTS static int getopts(char *optstr, char *optvar, char **optfirst) { char *p, *q; char c = '?'; int done = 0; char sbuf[2]; char **optnext; int ind = shellparam.optind; int off = shellparam.optoff; sbuf[1] = '\0'; shellparam.optind = -1; optnext = optfirst + ind - 1; if (ind <= 1 || off < 0 || (int)strlen(optnext[-1]) < off) p = NULL; else p = optnext[-1] + off; if (p == NULL || *p == '\0') { /* Current word is done, advance */ p = *optnext; if (p == NULL || *p != '-' || *++p == '\0') { atend: p = NULL; done = 1; goto out; } optnext++; if (LONE_DASH(p)) /* check for "--" */ goto atend; } c = *p++; for (q = optstr; *q != c;) { if (*q == '\0') { if (optstr[0] == ':') { sbuf[0] = c; /*sbuf[1] = '\0'; - already is */ setvar0("OPTARG", sbuf); } else { fprintf(stderr, "Illegal option -%c\n", c); unsetvar("OPTARG"); } c = '?'; goto out; } if (*++q == ':') q++; } if (*++q == ':') { if (*p == '\0' && (p = *optnext) == NULL) { if (optstr[0] == ':') { sbuf[0] = c; /*sbuf[1] = '\0'; - already is */ setvar0("OPTARG", sbuf); c = ':'; } else { fprintf(stderr, "No arg for -%c option\n", c); unsetvar("OPTARG"); c = '?'; } goto out; } if (p == *optnext) optnext++; setvar0("OPTARG", p); p = NULL; } else setvar0("OPTARG", nullstr); out: ind = optnext - optfirst + 1; setvar("OPTIND", itoa(ind), VNOFUNC); sbuf[0] = c; /*sbuf[1] = '\0'; - already is */ setvar0(optvar, sbuf); shellparam.optoff = p ? p - *(optnext - 1) : -1; shellparam.optind = ind; return done; } /* * The getopts builtin. Shellparam.optnext points to the next argument * to be processed. Shellparam.optptr points to the next character to * be processed in the current argument. If shellparam.optnext is NULL, * then it's the first time getopts has been called. */ static int FAST_FUNC getoptscmd(int argc, char **argv) { char **optbase; if (argc < 3) ash_msg_and_raise_error("usage: getopts optstring var [arg]"); if (argc == 3) { optbase = shellparam.p; if ((unsigned)shellparam.optind > shellparam.nparam + 1) { shellparam.optind = 1; shellparam.optoff = -1; } } else { optbase = &argv[3]; if ((unsigned)shellparam.optind > argc - 2) { shellparam.optind = 1; shellparam.optoff = -1; } } return getopts(argv[1], argv[2], optbase); } #endif /* ASH_GETOPTS */ /* ============ Shell parser */ struct heredoc { struct heredoc *next; /* next here document in list */ union node *here; /* redirection node */ char *eofmark; /* string indicating end of input */ smallint striptabs; /* if set, strip leading tabs */ }; static smallint tokpushback; /* last token pushed back */ static smallint quoteflag; /* set if (part of) last token was quoted */ static token_id_t lasttoken; /* last token read (integer id Txxx) */ static struct heredoc *heredoclist; /* list of here documents to read */ static char *wordtext; /* text of last word returned by readtoken */ static struct nodelist *backquotelist; static union node *redirnode; static struct heredoc *heredoc; static const char * tokname(char *buf, int tok) { if (tok < TSEMI) return tokname_array[tok]; sprintf(buf, "\"%s\"", tokname_array[tok]); return buf; } /* raise_error_unexpected_syntax: * Called when an unexpected token is read during the parse. The argument * is the token that is expected, or -1 if more than one type of token can * occur at this point. */ static void raise_error_unexpected_syntax(int) NORETURN; static void raise_error_unexpected_syntax(int token) { char msg[64]; char buf[16]; int l; l = sprintf(msg, "unexpected %s", tokname(buf, lasttoken)); if (token >= 0) sprintf(msg + l, " (expecting %s)", tokname(buf, token)); raise_error_syntax(msg); /* NOTREACHED */ } #define EOFMARKLEN 79 /* parsing is heavily cross-recursive, need these forward decls */ static union node *andor(void); static union node *pipeline(void); static union node *parse_command(void); static void parseheredoc(void); static int peektoken(void); static int readtoken(void); static union node * list(int nlflag) { union node *n1, *n2, *n3; int tok; n1 = NULL; for (;;) { switch (peektoken()) { case TNL: if (!(nlflag & 1)) break; parseheredoc(); return n1; case TEOF: if (!n1 && (nlflag & 1)) n1 = NODE_EOF; parseheredoc(); return n1; } checkkwd = CHKNL | CHKKWD | CHKALIAS; if (nlflag == 2 && ((1 << peektoken()) & tokendlist)) return n1; nlflag |= 2; n2 = andor(); tok = readtoken(); if (tok == TBACKGND) { if (n2->type == NPIPE) { n2->npipe.pipe_backgnd = 1; } else { if (n2->type != NREDIR) { n3 = stzalloc(sizeof(struct nredir)); n3->nredir.n = n2; /*n3->nredir.redirect = NULL; - stzalloc did it */ n2 = n3; } n2->type = NBACKGND; } } if (n1 == NULL) { n1 = n2; } else { n3 = stzalloc(sizeof(struct nbinary)); n3->type = NSEMI; n3->nbinary.ch1 = n1; n3->nbinary.ch2 = n2; n1 = n3; } switch (tok) { case TNL: case TEOF: tokpushback = 1; /* fall through */ case TBACKGND: case TSEMI: break; default: if ((nlflag & 1)) raise_error_unexpected_syntax(-1); tokpushback = 1; return n1; } } } static union node * andor(void) { union node *n1, *n2, *n3; int t; n1 = pipeline(); for (;;) { t = readtoken(); if (t == TAND) { t = NAND; } else if (t == TOR) { t = NOR; } else { tokpushback = 1; return n1; } checkkwd = CHKNL | CHKKWD | CHKALIAS; n2 = pipeline(); n3 = stzalloc(sizeof(struct nbinary)); n3->type = t; n3->nbinary.ch1 = n1; n3->nbinary.ch2 = n2; n1 = n3; } } static union node * pipeline(void) { union node *n1, *n2, *pipenode; struct nodelist *lp, *prev; int negate; negate = 0; TRACE(("pipeline: entered\n")); if (readtoken() == TNOT) { negate = !negate; checkkwd = CHKKWD | CHKALIAS; } else tokpushback = 1; n1 = parse_command(); if (readtoken() == TPIPE) { pipenode = stzalloc(sizeof(struct npipe)); pipenode->type = NPIPE; /*pipenode->npipe.pipe_backgnd = 0; - stzalloc did it */ lp = stzalloc(sizeof(struct nodelist)); pipenode->npipe.cmdlist = lp; lp->n = n1; do { prev = lp; lp = stzalloc(sizeof(struct nodelist)); checkkwd = CHKNL | CHKKWD | CHKALIAS; lp->n = parse_command(); prev->next = lp; } while (readtoken() == TPIPE); lp->next = NULL; n1 = pipenode; } tokpushback = 1; if (negate) { n2 = stzalloc(sizeof(struct nnot)); n2->type = NNOT; n2->nnot.com = n1; return n2; } return n1; } static union node * makename(void) { union node *n; n = stzalloc(sizeof(struct narg)); n->type = NARG; /*n->narg.next = NULL; - stzalloc did it */ n->narg.text = wordtext; n->narg.backquote = backquotelist; return n; } static void fixredir(union node *n, const char *text, int err) { int fd; TRACE(("Fix redir %s %d\n", text, err)); if (!err) n->ndup.vname = NULL; fd = bb_strtou(text, NULL, 10); if (!errno && fd >= 0) n->ndup.dupfd = fd; else if (LONE_DASH(text)) n->ndup.dupfd = -1; else { if (err) raise_error_syntax("bad fd number"); n->ndup.vname = makename(); } } /* * Returns true if the text contains nothing to expand (no dollar signs * or backquotes). */ static int noexpand(const char *text) { unsigned char c; while ((c = *text++) != '\0') { if (c == CTLQUOTEMARK) continue; if (c == CTLESC) text++; else if (SIT(c, BASESYNTAX) == CCTL) return 0; } return 1; } static void parsefname(void) { union node *n = redirnode; if (readtoken() != TWORD) raise_error_unexpected_syntax(-1); if (n->type == NHERE) { struct heredoc *here = heredoc; struct heredoc *p; int i; if (quoteflag == 0) n->type = NXHERE; TRACE(("Here document %d\n", n->type)); if (!noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) raise_error_syntax("illegal eof marker for << redirection"); rmescapes(wordtext, 0); here->eofmark = wordtext; here->next = NULL; if (heredoclist == NULL) heredoclist = here; else { for (p = heredoclist; p->next; p = p->next) continue; p->next = here; } } else if (n->type == NTOFD || n->type == NFROMFD) { fixredir(n, wordtext, 0); } else { n->nfile.fname = makename(); } } static union node * simplecmd(void) { union node *args, **app; union node *n = NULL; union node *vars, **vpp; union node **rpp, *redir; int savecheckkwd; #if BASH_TEST2 smallint double_brackets_flag = 0; #endif IF_BASH_FUNCTION(smallint function_flag = 0;) args = NULL; app = &args; vars = NULL; vpp = &vars; redir = NULL; rpp = &redir; savecheckkwd = CHKALIAS; for (;;) { int t; checkkwd = savecheckkwd; t = readtoken(); switch (t) { #if BASH_FUNCTION case TFUNCTION: if (peektoken() != TWORD) raise_error_unexpected_syntax(TWORD); function_flag = 1; break; #endif #if BASH_TEST2 case TAND: /* "&&" */ case TOR: /* "||" */ if (!double_brackets_flag) { tokpushback = 1; goto out; } wordtext = (char *) (t == TAND ? "-a" : "-o"); #endif case TWORD: n = stzalloc(sizeof(struct narg)); n->type = NARG; /*n->narg.next = NULL; - stzalloc did it */ n->narg.text = wordtext; #if BASH_TEST2 if (strcmp("[[", wordtext) == 0) double_brackets_flag = 1; else if (strcmp("]]", wordtext) == 0) double_brackets_flag = 0; #endif n->narg.backquote = backquotelist; if (savecheckkwd && isassignment(wordtext)) { *vpp = n; vpp = &n->narg.next; } else { *app = n; app = &n->narg.next; savecheckkwd = 0; } #if BASH_FUNCTION if (function_flag) { checkkwd = CHKNL | CHKKWD; switch (peektoken()) { case TBEGIN: case TIF: case TCASE: case TUNTIL: case TWHILE: case TFOR: goto do_func; case TLP: function_flag = 0; break; case TWORD: if (strcmp("[[", wordtext) == 0) goto do_func; /* fall through */ default: raise_error_unexpected_syntax(-1); } } #endif break; case TREDIR: *rpp = n = redirnode; rpp = &n->nfile.next; parsefname(); /* read name of redirection file */ break; case TLP: IF_BASH_FUNCTION(do_func:) if (args && app == &args->narg.next && !vars && !redir ) { struct builtincmd *bcmd; const char *name; /* We have a function */ if (IF_BASH_FUNCTION(!function_flag &&) readtoken() != TRP) raise_error_unexpected_syntax(TRP); name = n->narg.text; if (!goodname(name) || ((bcmd = find_builtin(name)) && IS_BUILTIN_SPECIAL(bcmd)) ) { raise_error_syntax("bad function name"); } n->type = NDEFUN; checkkwd = CHKNL | CHKKWD | CHKALIAS; n->narg.next = parse_command(); return n; } IF_BASH_FUNCTION(function_flag = 0;) /* fall through */ default: tokpushback = 1; goto out; } } out: *app = NULL; *vpp = NULL; *rpp = NULL; n = stzalloc(sizeof(struct ncmd)); n->type = NCMD; n->ncmd.args = args; n->ncmd.assign = vars; n->ncmd.redirect = redir; return n; } static union node * parse_command(void) { union node *n1, *n2; union node *ap, **app; union node *cp, **cpp; union node *redir, **rpp; union node **rpp2; int t; redir = NULL; rpp2 = &redir; switch (readtoken()) { default: raise_error_unexpected_syntax(-1); /* NOTREACHED */ case TIF: n1 = stzalloc(sizeof(struct nif)); n1->type = NIF; n1->nif.test = list(0); if (readtoken() != TTHEN) raise_error_unexpected_syntax(TTHEN); n1->nif.ifpart = list(0); n2 = n1; while (readtoken() == TELIF) { n2->nif.elsepart = stzalloc(sizeof(struct nif)); n2 = n2->nif.elsepart; n2->type = NIF; n2->nif.test = list(0); if (readtoken() != TTHEN) raise_error_unexpected_syntax(TTHEN); n2->nif.ifpart = list(0); } if (lasttoken == TELSE) n2->nif.elsepart = list(0); else { n2->nif.elsepart = NULL; tokpushback = 1; } t = TFI; break; case TWHILE: case TUNTIL: { int got; n1 = stzalloc(sizeof(struct nbinary)); n1->type = (lasttoken == TWHILE) ? NWHILE : NUNTIL; n1->nbinary.ch1 = list(0); got = readtoken(); if (got != TDO) { TRACE(("expecting DO got '%s' %s\n", tokname_array[got], got == TWORD ? wordtext : "")); raise_error_unexpected_syntax(TDO); } n1->nbinary.ch2 = list(0); t = TDONE; break; } case TFOR: if (readtoken() != TWORD || quoteflag || !goodname(wordtext)) raise_error_syntax("bad for loop variable"); n1 = stzalloc(sizeof(struct nfor)); n1->type = NFOR; n1->nfor.var = wordtext; checkkwd = CHKNL | CHKKWD | CHKALIAS; if (readtoken() == TIN) { app = ≈ while (readtoken() == TWORD) { n2 = stzalloc(sizeof(struct narg)); n2->type = NARG; /*n2->narg.next = NULL; - stzalloc did it */ n2->narg.text = wordtext; n2->narg.backquote = backquotelist; *app = n2; app = &n2->narg.next; } *app = NULL; n1->nfor.args = ap; if (lasttoken != TNL && lasttoken != TSEMI) raise_error_unexpected_syntax(-1); } else { n2 = stzalloc(sizeof(struct narg)); n2->type = NARG; /*n2->narg.next = NULL; - stzalloc did it */ n2->narg.text = (char *)dolatstr; /*n2->narg.backquote = NULL;*/ n1->nfor.args = n2; /* * Newline or semicolon here is optional (but note * that the original Bourne shell only allowed NL). */ if (lasttoken != TSEMI) tokpushback = 1; } checkkwd = CHKNL | CHKKWD | CHKALIAS; if (readtoken() != TDO) raise_error_unexpected_syntax(TDO); n1->nfor.body = list(0); t = TDONE; break; case TCASE: n1 = stzalloc(sizeof(struct ncase)); n1->type = NCASE; if (readtoken() != TWORD) raise_error_unexpected_syntax(TWORD); n1->ncase.expr = n2 = stzalloc(sizeof(struct narg)); n2->type = NARG; /*n2->narg.next = NULL; - stzalloc did it */ n2->narg.text = wordtext; n2->narg.backquote = backquotelist; checkkwd = CHKNL | CHKKWD | CHKALIAS; if (readtoken() != TIN) raise_error_unexpected_syntax(TIN); cpp = &n1->ncase.cases; next_case: checkkwd = CHKNL | CHKKWD; t = readtoken(); while (t != TESAC) { if (lasttoken == TLP) readtoken(); *cpp = cp = stzalloc(sizeof(struct nclist)); cp->type = NCLIST; app = &cp->nclist.pattern; for (;;) { *app = ap = stzalloc(sizeof(struct narg)); ap->type = NARG; /*ap->narg.next = NULL; - stzalloc did it */ ap->narg.text = wordtext; ap->narg.backquote = backquotelist; if (readtoken() != TPIPE) break; app = &ap->narg.next; readtoken(); } //ap->narg.next = NULL; if (lasttoken != TRP) raise_error_unexpected_syntax(TRP); cp->nclist.body = list(2); cpp = &cp->nclist.next; checkkwd = CHKNL | CHKKWD; t = readtoken(); if (t != TESAC) { if (t != TENDCASE) raise_error_unexpected_syntax(TENDCASE); goto next_case; } } *cpp = NULL; goto redir; case TLP: n1 = stzalloc(sizeof(struct nredir)); n1->type = NSUBSHELL; n1->nredir.n = list(0); /*n1->nredir.redirect = NULL; - stzalloc did it */ t = TRP; break; case TBEGIN: n1 = list(0); t = TEND; break; IF_BASH_FUNCTION(case TFUNCTION:) case TWORD: case TREDIR: tokpushback = 1; return simplecmd(); } if (readtoken() != t) raise_error_unexpected_syntax(t); redir: /* Now check for redirection which may follow command */ checkkwd = CHKKWD | CHKALIAS; rpp = rpp2; while (readtoken() == TREDIR) { *rpp = n2 = redirnode; rpp = &n2->nfile.next; parsefname(); } tokpushback = 1; *rpp = NULL; if (redir) { if (n1->type != NSUBSHELL) { n2 = stzalloc(sizeof(struct nredir)); n2->type = NREDIR; n2->nredir.n = n1; n1 = n2; } n1->nredir.redirect = redir; } return n1; } #if BASH_DOLLAR_SQUOTE static int decode_dollar_squote(void) { static const char C_escapes[] ALIGN1 = "nrbtfav""x\\01234567"; int c, cnt; char *p; char buf[4]; c = pgetc(); p = strchr(C_escapes, c); if (p) { buf[0] = c; p = buf; cnt = 3; if ((unsigned char)(c - '0') <= 7) { /* \ooo */ do { c = pgetc(); *++p = c; } while ((unsigned char)(c - '0') <= 7 && --cnt); pungetc(); } else if (c == 'x') { /* \xHH */ do { c = pgetc(); *++p = c; } while (isxdigit(c) && --cnt); pungetc(); if (cnt == 3) { /* \x but next char is "bad" */ c = 'x'; goto unrecognized; } } else { /* simple seq like \\ or \t */ p++; } *p = '\0'; p = buf; c = bb_process_escape_sequence((void*)&p); } else { /* unrecognized "\z": print both chars unless ' or " */ if (c != '\'' && c != '"') { unrecognized: c |= 0x100; /* "please encode \, then me" */ } } return c; } #endif /* * If eofmark is NULL, read a word or a redirection symbol. If eofmark * is not NULL, read a here document. In the latter case, eofmark is the * word which marks the end of the document and striptabs is true if * leading tabs should be stripped from the document. The argument c * is the first character of the input token or document. * * Because C does not have internal subroutines, I have simulated them * using goto's to implement the subroutine linkage. The following macros * will run code that appears at the end of readtoken1. */ #define CHECKEND() {goto checkend; checkend_return:;} #define PARSEREDIR() {goto parseredir; parseredir_return:;} #define PARSESUB() {goto parsesub; parsesub_return:;} #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;} #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;} #define PARSEARITH() {goto parsearith; parsearith_return:;} static int readtoken1(int c, int syntax, char *eofmark, int striptabs) { /* NB: syntax parameter fits into smallint */ /* c parameter is an unsigned char or PEOF or PEOA */ char *out; size_t len; char line[EOFMARKLEN + 1]; struct nodelist *bqlist; smallint quotef; smallint dblquote; smallint oldstyle; IF_FEATURE_SH_MATH(smallint prevsyntax;) /* syntax before arithmetic */ smallint pssyntax; /* we are expanding a prompt string */ int varnest; /* levels of variables expansion */ IF_FEATURE_SH_MATH(int arinest;) /* levels of arithmetic expansion */ IF_FEATURE_SH_MATH(int parenlevel;) /* levels of parens in arithmetic */ int dqvarnest; /* levels of variables expansion within double quotes */ IF_BASH_DOLLAR_SQUOTE(smallint bash_dollar_squote = 0;) startlinno = g_parsefile->linno; bqlist = NULL; quotef = 0; IF_FEATURE_SH_MATH(prevsyntax = 0;) pssyntax = (syntax == PSSYNTAX); if (pssyntax) syntax = DQSYNTAX; dblquote = (syntax == DQSYNTAX); varnest = 0; IF_FEATURE_SH_MATH(arinest = 0;) IF_FEATURE_SH_MATH(parenlevel = 0;) dqvarnest = 0; STARTSTACKSTR(out); loop: /* For each line, until end of word */ CHECKEND(); /* set c to PEOF if at end of here document */ for (;;) { /* until end of line or end of word */ CHECKSTRSPACE(4, out); /* permit 4 calls to USTPUTC */ switch (SIT(c, syntax)) { case CNL: /* '\n' */ if (syntax == BASESYNTAX) goto endword; /* exit outer loop */ USTPUTC(c, out); nlprompt(); c = pgetc(); goto loop; /* continue outer loop */ case CWORD: USTPUTC(c, out); break; case CCTL: #if BASH_DOLLAR_SQUOTE if (c == '\\' && bash_dollar_squote) { c = decode_dollar_squote(); if (c == '\0') { /* skip $'\000', $'\x00' (like bash) */ break; } if (c & 0x100) { /* Unknown escape. Encode as '\z' */ c = (unsigned char)c; if (eofmark == NULL || dblquote) USTPUTC(CTLESC, out); USTPUTC('\\', out); } } #endif if (eofmark == NULL || dblquote) USTPUTC(CTLESC, out); USTPUTC(c, out); break; case CBACK: /* backslash */ c = pgetc_without_PEOA(); if (c == PEOF) { USTPUTC(CTLESC, out); USTPUTC('\\', out); pungetc(); } else if (c == '\n') { nlprompt(); } else { if (c == '$' && pssyntax) { USTPUTC(CTLESC, out); USTPUTC('\\', out); } /* Backslash is retained if we are in "str" and next char isn't special */ if (dblquote && c != '\\' && c != '`' && c != '$' && (c != '"' || eofmark != NULL) ) { USTPUTC('\\', out); } USTPUTC(CTLESC, out); USTPUTC(c, out); quotef = 1; } break; case CSQUOTE: syntax = SQSYNTAX; quotemark: if (eofmark == NULL) { USTPUTC(CTLQUOTEMARK, out); } break; case CDQUOTE: syntax = DQSYNTAX; dblquote = 1; goto quotemark; case CENDQUOTE: IF_BASH_DOLLAR_SQUOTE(bash_dollar_squote = 0;) if (eofmark != NULL && varnest == 0) { USTPUTC(c, out); } else { if (dqvarnest == 0) { syntax = BASESYNTAX; dblquote = 0; } quotef = 1; goto quotemark; } break; case CVAR: /* '$' */ PARSESUB(); /* parse substitution */ break; case CENDVAR: /* '}' */ if (varnest > 0) { varnest--; if (dqvarnest > 0) { dqvarnest--; } c = CTLENDVAR; } USTPUTC(c, out); break; #if ENABLE_FEATURE_SH_MATH case CLP: /* '(' in arithmetic */ parenlevel++; USTPUTC(c, out); break; case CRP: /* ')' in arithmetic */ if (parenlevel > 0) { parenlevel--; } else { if (pgetc_eatbnl() == ')') { c = CTLENDARI; if (--arinest == 0) { syntax = prevsyntax; } } else { /* * unbalanced parens * (don't 2nd guess - no error) */ pungetc(); } } USTPUTC(c, out); break; #endif case CBQUOTE: /* '`' */ PARSEBACKQOLD(); break; case CENDFILE: goto endword; /* exit outer loop */ case CIGN: break; default: if (varnest == 0) { #if BASH_REDIR_OUTPUT if (c == '&') { //Can't call pgetc_eatbnl() here, this requires three-deep pungetc() if (pgetc() == '>') c = 0x100 + '>'; /* flag &> */ pungetc(); } #endif goto endword; /* exit outer loop */ } IF_ASH_ALIAS(if (c != PEOA)) USTPUTC(c, out); } c = pgetc(); } /* for (;;) */ endword: #if ENABLE_FEATURE_SH_MATH if (syntax == ARISYNTAX) raise_error_syntax("missing '))'"); #endif if (syntax != BASESYNTAX && eofmark == NULL) raise_error_syntax("unterminated quoted string"); if (varnest != 0) { startlinno = g_parsefile->linno; /* { */ raise_error_syntax("missing '}'"); } USTPUTC('\0', out); len = out - (char *)stackblock(); out = stackblock(); if (eofmark == NULL) { if ((c == '>' || c == '<' IF_BASH_REDIR_OUTPUT( || c == 0x100 + '>')) && quotef == 0 ) { if (isdigit_str9(out)) { PARSEREDIR(); /* passed as params: out, c */ lasttoken = TREDIR; return lasttoken; } /* else: non-number X seen, interpret it * as "NNNX>file" = "NNNX >file" */ } pungetc(); } quoteflag = quotef; backquotelist = bqlist; grabstackblock(len); wordtext = out; lasttoken = TWORD; return lasttoken; /* end of readtoken routine */ /* * Check to see whether we are at the end of the here document. When this * is called, c is set to the first character of the next input line. If * we are at the end of the here document, this routine sets the c to PEOF. */ checkend: { if (eofmark) { #if ENABLE_ASH_ALIAS if (c == PEOA) c = pgetc_without_PEOA(); #endif if (striptabs) { while (c == '\t') { c = pgetc_without_PEOA(); } } if (c == *eofmark) { if (pfgets(line, sizeof(line)) != NULL) { char *p, *q; int cc; p = line; for (q = eofmark + 1;; p++, q++) { cc = *p; if (cc == '\n') cc = 0; if (!*q || cc != *q) break; } if (cc == *q) { c = PEOF; nlnoprompt(); } else { pushstring(line, NULL); } } } } goto checkend_return; } /* * Parse a redirection operator. The variable "out" points to a string * specifying the fd to be redirected. The variable "c" contains the * first character of the redirection operator. */ parseredir: { /* out is already checked to be a valid number or "" */ int fd = (*out == '\0' ? -1 : atoi(out)); union node *np; np = stzalloc(sizeof(struct nfile)); if (c == '>') { np->nfile.fd = 1; c = pgetc(); if (c == '>') np->type = NAPPEND; else if (c == '|') np->type = NCLOBBER; else if (c == '&') np->type = NTOFD; /* it also can be NTO2 (>&file), but we can't figure it out yet */ else { np->type = NTO; pungetc(); } } #if BASH_REDIR_OUTPUT else if (c == 0x100 + '>') { /* this flags &> redirection */ np->nfile.fd = 1; pgetc(); /* this is '>', no need to check */ np->type = NTO2; } #endif else { /* c == '<' */ /*np->nfile.fd = 0; - stzalloc did it */ c = pgetc(); switch (c) { case '<': if (sizeof(struct nfile) != sizeof(struct nhere)) { np = stzalloc(sizeof(struct nhere)); /*np->nfile.fd = 0; - stzalloc did it */ } np->type = NHERE; heredoc = stzalloc(sizeof(struct heredoc)); heredoc->here = np; c = pgetc(); if (c == '-') { heredoc->striptabs = 1; } else { /*heredoc->striptabs = 0; - stzalloc did it */ pungetc(); } break; case '&': np->type = NFROMFD; break; case '>': np->type = NFROMTO; break; default: np->type = NFROM; pungetc(); break; } } if (fd >= 0) np->nfile.fd = fd; redirnode = np; goto parseredir_return; } /* * Parse a substitution. At this point, we have read the dollar sign * and nothing else. */ /* is_special(c) evaluates to 1 for c in "!#$*-0123456789?@"; 0 otherwise * (assuming ascii char codes, as the original implementation did) */ #define is_special(c) \ (((unsigned)(c) - 33 < 32) \ && ((0xc1ff920dU >> ((unsigned)(c) - 33)) & 1)) parsesub: { unsigned char subtype; int typeloc; c = pgetc_eatbnl(); if (c > 255 /* PEOA or PEOF */ || (c != '(' && c != '{' && !is_name(c) && !is_special(c)) ) { #if BASH_DOLLAR_SQUOTE if (syntax != DQSYNTAX && c == '\'') bash_dollar_squote = 1; else #endif USTPUTC('$', out); pungetc(); } else if (c == '(') { /* $(command) or $((arith)) */ if (pgetc_eatbnl() == '(') { #if ENABLE_FEATURE_SH_MATH PARSEARITH(); #else raise_error_syntax("you disabled math support for $((arith)) syntax"); #endif } else { pungetc(); PARSEBACKQNEW(); } } else { /* $VAR, $, ${...}, or PEOA/PEOF */ USTPUTC(CTLVAR, out); typeloc = out - (char *)stackblock(); STADJUST(1, out); subtype = VSNORMAL; if (c == '{') { c = pgetc_eatbnl(); subtype = 0; } varname: if (is_name(c)) { /* $[{[#]]NAME[}] */ do { STPUTC(c, out); c = pgetc_eatbnl(); } while (is_in_name(c)); } else if (isdigit(c)) { /* $[{[#]]NUM[}] */ do { STPUTC(c, out); c = pgetc_eatbnl(); } while (isdigit(c)); } else if (is_special(c)) { /* $[{[#]][}] */ int cc = c; c = pgetc_eatbnl(); if (!subtype && cc == '#') { subtype = VSLENGTH; if (c == '_' || isalnum(c)) goto varname; cc = c; c = pgetc_eatbnl(); if (cc == '}' || c != '}') { pungetc(); subtype = 0; c = cc; cc = '#'; } } USTPUTC(cc, out); } else { goto badsub; } if (c != '}' && subtype == VSLENGTH) { /* ${#VAR didn't end with } */ goto badsub; } if (subtype == 0) { static const char types[] ALIGN1 = "}-+?="; /* ${VAR...} but not $VAR or ${#VAR} */ /* c == first char after VAR */ switch (c) { case ':': c = pgetc_eatbnl(); #if BASH_SUBSTR /* This check is only needed to not misinterpret * ${VAR:-WORD}, ${VAR:+WORD}, ${VAR:=WORD}, ${VAR:?WORD} * constructs. */ if (!strchr(types, c)) { subtype = VSSUBSTR; pungetc(); break; /* "goto badsub" is bigger (!) */ } #endif subtype = VSNUL; /*FALLTHROUGH*/ default: { const char *p = strchr(types, c); if (p == NULL) break; subtype |= p - types + VSNORMAL; break; } case '%': case '#': { int cc = c; subtype = (c == '#' ? VSTRIMLEFT : VSTRIMRIGHT); c = pgetc_eatbnl(); if (c != cc) goto badsub; subtype++; break; } #if BASH_PATTERN_SUBST case '/': /* ${v/[/]pattern/repl} */ //TODO: encode pattern and repl separately. // Currently ${v/$var_with_slash/repl} is horribly broken subtype = VSREPLACE; c = pgetc_eatbnl(); if (c != '/') goto badsub; subtype++; /* VSREPLACEALL */ break; #endif } } else { badsub: pungetc(); } ((unsigned char *)stackblock())[typeloc] = subtype; if (subtype != VSNORMAL) { varnest++; if (dblquote) dqvarnest++; } STPUTC('=', out); } goto parsesub_return; } /* * Called to parse command substitutions. Newstyle is set if the command * is enclosed inside $(...); nlpp is a pointer to the head of the linked * list of commands (passed by reference), and savelen is the number of * characters on the top of the stack which must be preserved. */ parsebackq: { struct nodelist **nlpp; union node *n; char *str; size_t savelen; smallint saveprompt = 0; str = NULL; savelen = out - (char *)stackblock(); if (savelen > 0) { /* * FIXME: this can allocate very large block on stack and SEGV. * Example: * echo "..<100kbytes>..`true` $(true) `true` ..." * allocates 100kb for every command subst. With about * a hundred command substitutions stack overflows. * With larger prepended string, SEGV happens sooner. */ str = alloca(savelen); memcpy(str, stackblock(), savelen); } if (oldstyle) { /* We must read until the closing backquote, giving special * treatment to some slashes, and then push the string and * reread it as input, interpreting it normally. */ char *pout; size_t psavelen; char *pstr; STARTSTACKSTR(pout); for (;;) { int pc; setprompt_if(needprompt, 2); pc = pgetc(); switch (pc) { case '`': goto done; case '\\': pc = pgetc(); if (pc == '\n') { nlprompt(); /* * If eating a newline, avoid putting * the newline into the new character * stream (via the STPUTC after the * switch). */ continue; } if (pc != '\\' && pc != '`' && pc != '$' && (!dblquote || pc != '"') ) { STPUTC('\\', pout); } if (pc <= 255 /* not PEOA or PEOF */) { break; } /* fall through */ case PEOF: IF_ASH_ALIAS(case PEOA:) startlinno = g_parsefile->linno; raise_error_syntax("EOF in backquote substitution"); case '\n': nlnoprompt(); break; default: break; } STPUTC(pc, pout); } done: STPUTC('\0', pout); psavelen = pout - (char *)stackblock(); if (psavelen > 0) { pstr = grabstackstr(pout); setinputstring(pstr); } } nlpp = &bqlist; while (*nlpp) nlpp = &(*nlpp)->next; *nlpp = stzalloc(sizeof(**nlpp)); /* (*nlpp)->next = NULL; - stzalloc did it */ if (oldstyle) { saveprompt = doprompt; doprompt = 0; } n = list(2); if (oldstyle) doprompt = saveprompt; else if (readtoken() != TRP) raise_error_unexpected_syntax(TRP); (*nlpp)->n = n; if (oldstyle) { /* * Start reading from old file again, ignoring any pushed back * tokens left from the backquote parsing */ popfile(); tokpushback = 0; } while (stackblocksize() <= savelen) growstackblock(); STARTSTACKSTR(out); if (str) { memcpy(out, str, savelen); STADJUST(savelen, out); } USTPUTC(CTLBACKQ, out); if (oldstyle) goto parsebackq_oldreturn; goto parsebackq_newreturn; } #if ENABLE_FEATURE_SH_MATH /* * Parse an arithmetic expansion (indicate start of one and set state) */ parsearith: { if (++arinest == 1) { prevsyntax = syntax; syntax = ARISYNTAX; } USTPUTC(CTLARI, out); goto parsearith_return; } #endif } /* end of readtoken */ /* * Read the next input token. * If the token is a word, we set backquotelist to the list of cmds in * backquotes. We set quoteflag to true if any part of the word was * quoted. * If the token is TREDIR, then we set redirnode to a structure containing * the redirection. * In all cases, the variable startlinno is set to the number of the line * on which the token starts. * * [Change comment: here documents and internal procedures] * [Readtoken shouldn't have any arguments. Perhaps we should make the * word parsing code into a separate routine. In this case, readtoken * doesn't need to have any internal procedures, but parseword does. * We could also make parseoperator in essence the main routine, and * have parseword (readtoken1?) handle both words and redirection.] */ #define NEW_xxreadtoken #ifdef NEW_xxreadtoken /* singles must be first! */ static const char xxreadtoken_chars[7] ALIGN1 = { '\n', '(', ')', /* singles */ '&', '|', ';', /* doubles */ 0 }; #define xxreadtoken_singles 3 #define xxreadtoken_doubles 3 static const char xxreadtoken_tokens[] ALIGN1 = { TNL, TLP, TRP, /* only single occurrence allowed */ TBACKGND, TPIPE, TSEMI, /* if single occurrence */ TEOF, /* corresponds to trailing nul */ TAND, TOR, TENDCASE /* if double occurrence */ }; static int xxreadtoken(void) { int c; if (tokpushback) { tokpushback = 0; return lasttoken; } setprompt_if(needprompt, 2); startlinno = g_parsefile->linno; for (;;) { /* until token or start of word found */ c = pgetc(); if (c == ' ' || c == '\t' IF_ASH_ALIAS( || c == PEOA)) continue; if (c == '#') { while ((c = pgetc()) != '\n' && c != PEOF) continue; pungetc(); } else if (c == '\\') { if (pgetc() != '\n') { pungetc(); break; /* return readtoken1(...) */ } nlprompt(); } else { const char *p; p = xxreadtoken_chars + sizeof(xxreadtoken_chars) - 1; if (c != PEOF) { if (c == '\n') { nlnoprompt(); } p = strchr(xxreadtoken_chars, c); if (p == NULL) break; /* return readtoken1(...) */ if ((int)(p - xxreadtoken_chars) >= xxreadtoken_singles) { int cc = pgetc(); if (cc == c) { /* double occurrence? */ p += xxreadtoken_doubles + 1; } else { pungetc(); #if BASH_REDIR_OUTPUT if (c == '&' && cc == '>') /* &> */ break; /* return readtoken1(...) */ #endif } } } lasttoken = xxreadtoken_tokens[p - xxreadtoken_chars]; return lasttoken; } } /* for (;;) */ return readtoken1(c, BASESYNTAX, (char *) NULL, 0); } #else /* old xxreadtoken */ #define RETURN(token) return lasttoken = token static int xxreadtoken(void) { int c; if (tokpushback) { tokpushback = 0; return lasttoken; } setprompt_if(needprompt, 2); startlinno = g_parsefile->linno; for (;;) { /* until token or start of word found */ c = pgetc(); switch (c) { case ' ': case '\t': IF_ASH_ALIAS(case PEOA:) continue; case '#': while ((c = pgetc()) != '\n' && c != PEOF) continue; pungetc(); continue; case '\\': if (pgetc() == '\n') { nlprompt(); continue; } pungetc(); goto breakloop; case '\n': nlnoprompt(); RETURN(TNL); case PEOF: RETURN(TEOF); case '&': if (pgetc() == '&') RETURN(TAND); pungetc(); RETURN(TBACKGND); case '|': if (pgetc() == '|') RETURN(TOR); pungetc(); RETURN(TPIPE); case ';': if (pgetc() == ';') RETURN(TENDCASE); pungetc(); RETURN(TSEMI); case '(': RETURN(TLP); case ')': RETURN(TRP); default: goto breakloop; } } breakloop: return readtoken1(c, BASESYNTAX, (char *)NULL, 0); #undef RETURN } #endif /* old xxreadtoken */ static int readtoken(void) { int t; int kwd = checkkwd; #if DEBUG smallint alreadyseen = tokpushback; #endif #if ENABLE_ASH_ALIAS top: #endif t = xxreadtoken(); /* * eat newlines */ if (kwd & CHKNL) { while (t == TNL) { parseheredoc(); t = xxreadtoken(); } } if (t != TWORD || quoteflag) { goto out; } /* * check for keywords */ if (kwd & CHKKWD) { const char *const *pp; pp = findkwd(wordtext); if (pp) { lasttoken = t = pp - tokname_array; TRACE(("keyword '%s' recognized\n", tokname_array[t])); goto out; } } if (checkkwd & CHKALIAS) { #if ENABLE_ASH_ALIAS struct alias *ap; ap = lookupalias(wordtext, 1); if (ap != NULL) { if (*ap->val) { pushstring(ap->val, ap); } goto top; } #endif } out: checkkwd = 0; #if DEBUG if (!alreadyseen) TRACE(("token '%s' %s\n", tokname_array[t], t == TWORD ? wordtext : "")); else TRACE(("reread token '%s' %s\n", tokname_array[t], t == TWORD ? wordtext : "")); #endif return t; } static int peektoken(void) { int t; t = readtoken(); tokpushback = 1; return t; } /* * Read and parse a command. Returns NODE_EOF on end of file. * (NULL is a valid parse tree indicating a blank line.) */ static union node * parsecmd(int interact) { tokpushback = 0; checkkwd = 0; heredoclist = 0; doprompt = interact; setprompt_if(doprompt, doprompt); needprompt = 0; return list(1); } /* * Input any here documents. */ static void parseheredoc(void) { struct heredoc *here; union node *n; here = heredoclist; heredoclist = NULL; while (here) { setprompt_if(needprompt, 2); readtoken1(pgetc(), here->here->type == NHERE ? SQSYNTAX : DQSYNTAX, here->eofmark, here->striptabs); n = stzalloc(sizeof(struct narg)); n->narg.type = NARG; /*n->narg.next = NULL; - stzalloc did it */ n->narg.text = wordtext; n->narg.backquote = backquotelist; here->here->nhere.doc = n; here = here->next; } } /* * called by editline -- any expansions to the prompt should be added here. */ static const char * expandstr(const char *ps) { union node n; int saveprompt; /* XXX Fix (char *) cast. It _is_ a bug. ps is variable's value, * and token processing _can_ alter it (delete NULs etc). */ setinputstring((char *)ps); saveprompt = doprompt; doprompt = 0; readtoken1(pgetc(), PSSYNTAX, nullstr, 0); doprompt = saveprompt; popfile(); n.narg.type = NARG; n.narg.next = NULL; n.narg.text = wordtext; n.narg.backquote = backquotelist; expandarg(&n, NULL, EXP_QUOTED); return stackblock(); } /* * Execute a command or commands contained in a string. */ static int evalstring(char *s, int flags) { struct jmploc *volatile savehandler; struct jmploc jmploc; int ex; union node *n; struct stackmark smark; int status; s = sstrdup(s); setinputstring(s); setstackmark(&smark); status = 0; /* On exception inside execution loop, we must popfile(). * Try interactively: * readonly a=a * command eval "a=b" # throws "is read only" error * "command BLTIN" is not supposed to abort (even in non-interactive use). * But if we skip popfile(), we hit EOF in eval's string, and exit. */ savehandler = exception_handler; ex = setjmp(jmploc.loc); if (ex) goto out; exception_handler = &jmploc; while ((n = parsecmd(0)) != NODE_EOF) { int i; i = evaltree(n, flags); if (n) status = i; popstackmark(&smark); if (evalskip) break; } out: popstackmark(&smark); popfile(); stunalloc(s); exception_handler = savehandler; if (ex) longjmp(exception_handler->loc, ex); return status; } /* * The eval command. */ static int FAST_FUNC evalcmd(int argc UNUSED_PARAM, char **argv, int flags) { char *p; char *concat; if (argv[1]) { p = argv[1]; argv += 2; if (argv[0]) { STARTSTACKSTR(concat); for (;;) { concat = stack_putstr(p, concat); p = *argv++; if (p == NULL) break; STPUTC(' ', concat); } STPUTC('\0', concat); p = grabstackstr(concat); } return evalstring(p, flags & EV_TESTED); } return 0; } /* * Read and execute commands. * "Top" is nonzero for the top level command loop; * it turns on prompting if the shell is interactive. */ static int cmdloop(int top) { union node *n; struct stackmark smark; int inter; int status = 0; int numeof = 0; TRACE(("cmdloop(%d) called\n", top)); for (;;) { int skip; setstackmark(&smark); #if JOBS if (doing_jobctl) showjobs(SHOW_CHANGED|SHOW_STDERR); #endif inter = 0; if (iflag && top) { inter++; chkmail(); } n = parsecmd(inter); #if DEBUG if (DEBUG > 2 && debug && (n != NODE_EOF)) showtree(n); #endif if (n == NODE_EOF) { if (!top || numeof >= 50) break; if (!stoppedjobs()) { if (!Iflag) break; out2str("\nUse \"exit\" to leave shell.\n"); } numeof++; } else if (nflag == 0) { int i; /* job_warning can only be 2,1,0. Here 2->1, 1/0->0 */ job_warning >>= 1; numeof = 0; i = evaltree(n, 0); if (n) status = i; } popstackmark(&smark); skip = evalskip; if (skip) { evalskip &= ~SKIPFUNC; break; } } return status; } /* * Take commands from a file. To be compatible we should do a path * search for the file, which is necessary to find sub-commands. */ static char * find_dot_file(char *name) { char *fullname; const char *path = pathval(); struct stat statb; /* don't try this for absolute or relative paths */ if (strchr(name, '/')) return name; while ((fullname = path_advance(&path, name)) != NULL) { if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) { /* * Don't bother freeing here, since it will * be freed by the caller. */ return fullname; } if (fullname != name) stunalloc(fullname); } /* not found in the PATH */ ash_msg_and_raise_error("%s: not found", name); /* NOTREACHED */ } static int FAST_FUNC dotcmd(int argc_ UNUSED_PARAM, char **argv_ UNUSED_PARAM) { /* "false; . empty_file; echo $?" should print 0, not 1: */ int status = 0; char *fullname; char **argv; char *args_need_save; struct strlist *sp; volatile struct shparam saveparam; for (sp = cmdenviron; sp; sp = sp->next) setvareq(ckstrdup(sp->text), VSTRFIXED | VTEXTFIXED); nextopt(nullstr); /* handle possible "--" */ argv = argptr; if (!argv[0]) { /* bash says: "bash: .: filename argument required" */ return 2; /* bash compat */ } /* This aborts if file isn't found, which is POSIXly correct. * bash returns exitcode 1 instead. */ fullname = find_dot_file(argv[0]); argv++; args_need_save = argv[0]; if (args_need_save) { /* ". FILE ARGS", and ARGS are not empty */ int argc; saveparam = shellparam; shellparam.malloced = 0; argc = 1; while (argv[argc]) argc++; shellparam.nparam = argc; shellparam.p = argv; }; /* This aborts if file can't be opened, which is POSIXly correct. * bash returns exitcode 1 instead. */ setinputfile(fullname, INPUT_PUSH_FILE); commandname = fullname; status = cmdloop(0); popfile(); if (args_need_save) { freeparam(&shellparam); shellparam = saveparam; }; return status; } static int FAST_FUNC exitcmd(int argc UNUSED_PARAM, char **argv) { if (stoppedjobs()) return 0; if (argv[1]) exitstatus = number(argv[1]); raise_exception(EXEXIT); /* NOTREACHED */ } /* * Read a file containing shell functions. */ static void readcmdfile(char *name) { setinputfile(name, INPUT_PUSH_FILE); cmdloop(0); popfile(); } /* ============ find_command inplementation */ /* * Resolve a command name. If you change this routine, you may have to * change the shellexec routine as well. */ static void find_command(char *name, struct cmdentry *entry, int act, const char *path) { struct tblentry *cmdp; int idx; int prev; char *fullname; struct stat statb; int e; int updatetbl; struct builtincmd *bcmd; /* If name contains a slash, don't use PATH or hash table */ if (strchr(name, '/') != NULL) { entry->u.index = -1; if (act & DO_ABS) { while (stat(name, &statb) < 0) { #ifdef SYSV if (errno == EINTR) continue; #endif entry->cmdtype = CMDUNKNOWN; return; } } entry->cmdtype = CMDNORMAL; return; } /* #if ENABLE_FEATURE_SH_STANDALONE... moved after builtin check */ updatetbl = (path == pathval()); if (!updatetbl) { act |= DO_ALTPATH; if (strstr(path, "%builtin") != NULL) act |= DO_ALTBLTIN; } /* If name is in the table, check answer will be ok */ cmdp = cmdlookup(name, 0); if (cmdp != NULL) { int bit; switch (cmdp->cmdtype) { default: #if DEBUG abort(); #endif case CMDNORMAL: bit = DO_ALTPATH; break; case CMDFUNCTION: bit = DO_NOFUNC; break; case CMDBUILTIN: bit = DO_ALTBLTIN; break; } if (act & bit) { updatetbl = 0; cmdp = NULL; } else if (cmdp->rehash == 0) /* if not invalidated by cd, we're done */ goto success; } /* If %builtin not in path, check for builtin next */ bcmd = find_builtin(name); if (bcmd) { if (IS_BUILTIN_REGULAR(bcmd)) goto builtin_success; if (act & DO_ALTPATH) { if (!(act & DO_ALTBLTIN)) goto builtin_success; } else if (builtinloc <= 0) { goto builtin_success; } } #if ENABLE_FEATURE_SH_STANDALONE { int applet_no = find_applet_by_name(name); if (applet_no >= 0) { entry->cmdtype = CMDNORMAL; entry->u.index = -2 - applet_no; return; } } #endif /* We have to search path. */ prev = -1; /* where to start */ if (cmdp && cmdp->rehash) { /* doing a rehash */ if (cmdp->cmdtype == CMDBUILTIN) prev = builtinloc; else prev = cmdp->param.index; } e = ENOENT; idx = -1; loop: while ((fullname = path_advance(&path, name)) != NULL) { stunalloc(fullname); /* NB: code below will still use fullname * despite it being "unallocated" */ idx++; if (pathopt) { if (prefix(pathopt, "builtin")) { if (bcmd) goto builtin_success; continue; } if ((act & DO_NOFUNC) || !prefix(pathopt, "func") ) { /* ignore unimplemented options */ continue; } } /* if rehash, don't redo absolute path names */ if (fullname[0] == '/' && idx <= prev) { if (idx < prev) continue; TRACE(("searchexec \"%s\": no change\n", name)); goto success; } while (stat(fullname, &statb) < 0) { #ifdef SYSV if (errno == EINTR) continue; #endif if (errno != ENOENT && errno != ENOTDIR) e = errno; goto loop; } e = EACCES; /* if we fail, this will be the error */ if (!S_ISREG(statb.st_mode)) continue; if (pathopt) { /* this is a %func directory */ stalloc(strlen(fullname) + 1); /* NB: stalloc will return space pointed by fullname * (because we don't have any intervening allocations * between stunalloc above and this stalloc) */ readcmdfile(fullname); cmdp = cmdlookup(name, 0); if (cmdp == NULL || cmdp->cmdtype != CMDFUNCTION) ash_msg_and_raise_error("%s not defined in %s", name, fullname); stunalloc(fullname); goto success; } TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname)); if (!updatetbl) { entry->cmdtype = CMDNORMAL; entry->u.index = idx; return; } INT_OFF; cmdp = cmdlookup(name, 1); cmdp->cmdtype = CMDNORMAL; cmdp->param.index = idx; INT_ON; goto success; } /* We failed. If there was an entry for this command, delete it */ if (cmdp && updatetbl) delete_cmd_entry(); if (act & DO_ERR) ash_msg("%s: %s", name, errmsg(e, "not found")); entry->cmdtype = CMDUNKNOWN; return; builtin_success: if (!updatetbl) { entry->cmdtype = CMDBUILTIN; entry->u.cmd = bcmd; return; } INT_OFF; cmdp = cmdlookup(name, 1); cmdp->cmdtype = CMDBUILTIN; cmdp->param.cmd = bcmd; INT_ON; success: cmdp->rehash = 0; entry->cmdtype = cmdp->cmdtype; entry->u = cmdp->param; } /* * The trap builtin. */ static int FAST_FUNC trapcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { char *action; char **ap; int signo, exitcode; nextopt(nullstr); ap = argptr; if (!*ap) { for (signo = 0; signo < NSIG; signo++) { char *tr = trap_ptr[signo]; if (tr) { /* 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: */ out1fmt("trap -- %s %s\n", single_quote(tr), get_signame(signo)); /* trap_ptr != trap only if we are in special-cased `trap` code. * In this case, we will exit very soon, no need to free(). */ /* if (trap_ptr != trap && tp[0]) */ /* free(tr); */ } } /* if (trap_ptr != trap) { free(trap_ptr); trap_ptr = trap; } */ return 0; } action = NULL; if (ap[1]) action = *ap++; exitcode = 0; while (*ap) { signo = get_signum(*ap); if (signo < 0 || signo >= NSIG) { /* Mimic bash message exactly */ ash_msg("%s: invalid signal specification", *ap); exitcode = 1; goto next; } INT_OFF; if (action) { if (LONE_DASH(action)) action = NULL; else { if (action[0]) /* not NULL and not "" and not "-" */ may_have_traps = 1; action = ckstrdup(action); } } free(trap[signo]); trap[signo] = action; if (signo != 0) setsignal(signo); INT_ON; next: ap++; } return exitcode; } /* ============ Builtins */ #if ENABLE_ASH_HELP static int FAST_FUNC helpcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { unsigned col; unsigned i; out1fmt( "Built-in commands:\n" "------------------\n"); for (col = 0, i = 0; i < ARRAY_SIZE(builtintab); i++) { col += out1fmt("%c%s", ((col == 0) ? '\t' : ' '), builtintab[i].name + 1); if (col > 60) { out1fmt("\n"); col = 0; } } # if ENABLE_FEATURE_SH_STANDALONE { const char *a = applet_names; while (*a) { col += out1fmt("%c%s", ((col == 0) ? '\t' : ' '), a); if (col > 60) { out1fmt("\n"); col = 0; } while (*a++ != '\0') continue; } } # endif newline_and_flush(stdout); return EXIT_SUCCESS; } #endif #if MAX_HISTORY static int FAST_FUNC historycmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { show_history(line_input_state); return EXIT_SUCCESS; } #endif /* * The export and readonly commands. */ static int FAST_FUNC exportcmd(int argc UNUSED_PARAM, char **argv) { struct var *vp; char *name; const char *p; char **aptr; char opt; int flag; int flag_off; /* "readonly" in bash accepts, but ignores -n. * We do the same: it saves a conditional in nextopt's param. */ flag_off = 0; while ((opt = nextopt("np")) != '\0') { if (opt == 'n') flag_off = VEXPORT; } flag = VEXPORT; if (argv[0][0] == 'r') { flag = VREADONLY; flag_off = 0; /* readonly ignores -n */ } flag_off = ~flag_off; /*if (opt_p_not_specified) - bash doesn't check this. Try "export -p NAME" */ { aptr = argptr; name = *aptr; if (name) { do { p = strchr(name, '='); if (p != NULL) { p++; } else { vp = *findvar(hashvar(name), name); if (vp) { vp->flags = ((vp->flags | flag) & flag_off); continue; } } setvar(name, p, (flag & flag_off)); } while ((name = *++aptr) != NULL); return 0; } } /* No arguments. Show the list of exported or readonly vars. * -n is ignored. */ showvars(argv[0], flag, 0); return 0; } /* * Delete a function if it exists. */ static void unsetfunc(const char *name) { struct tblentry *cmdp; cmdp = cmdlookup(name, 0); if (cmdp != NULL && cmdp->cmdtype == CMDFUNCTION) delete_cmd_entry(); } /* * The unset builtin command. We unset the function before we unset the * variable to allow a function to be unset when there is a readonly variable * with the same name. */ static int FAST_FUNC unsetcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { char **ap; int i; int flag = 0; int ret = 0; while ((i = nextopt("vf")) != 0) { flag = i; } for (ap = argptr; *ap; ap++) { if (flag != 'f') { i = unsetvar(*ap); ret |= i; if (!(i & 2)) continue; } if (flag != 'v') unsetfunc(*ap); } return ret & 1; } static const unsigned char timescmd_str[] ALIGN1 = { ' ', offsetof(struct tms, tms_utime), '\n', offsetof(struct tms, tms_stime), ' ', offsetof(struct tms, tms_cutime), '\n', offsetof(struct tms, tms_cstime), 0 }; static int FAST_FUNC timescmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { unsigned long clk_tck, s, t; const unsigned char *p; struct tms buf; clk_tck = bb_clk_tck(); times(&buf); p = timescmd_str; do { t = *(clock_t *)(((char *) &buf) + p[1]); s = t / clk_tck; t = t % clk_tck; out1fmt("%lum%lu.%03lus%c", s / 60, s % 60, (t * 1000) / clk_tck, p[0]); p += 2; } while (*p); return 0; } #if ENABLE_FEATURE_SH_MATH /* * The let builtin. Partially stolen from GNU Bash, the Bourne Again SHell. * Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc. * * Copyright (C) 2003 Vladimir Oleynik */ static int FAST_FUNC letcmd(int argc UNUSED_PARAM, char **argv) { arith_t i; argv++; if (!*argv) ash_msg_and_raise_error("expression expected"); do { i = ash_arith(*argv); } while (*++argv); return !i; } #endif /* * The read builtin. Options: * -r Do not interpret '\' specially * -s Turn off echo (tty only) * -n NCHARS Read NCHARS max * -p PROMPT Display PROMPT on stderr (if input is from tty) * -t SECONDS Timeout after SECONDS (tty or pipe only) * -u FD Read from given FD instead of fd 0 * This uses unbuffered input, which may be avoidable in some cases. * TODO: bash also has: * -a ARRAY Read into array[0],[1],etc * -d DELIM End on DELIM char, not newline * -e Use line editing (tty only) */ static int FAST_FUNC readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { char *opt_n = NULL; char *opt_p = NULL; char *opt_t = NULL; char *opt_u = NULL; int read_flags = 0; const char *r; int i; while ((i = nextopt("p:u:rt:n:s")) != '\0') { switch (i) { case 'p': opt_p = optionarg; break; case 'n': opt_n = optionarg; break; case 's': read_flags |= BUILTIN_READ_SILENT; break; case 't': opt_t = optionarg; break; case 'r': read_flags |= BUILTIN_READ_RAW; break; case 'u': opt_u = optionarg; break; default: break; } } /* "read -s" needs to save/restore termios, can't allow ^C * to jump out of it. */ again: INT_OFF; r = shell_builtin_read(setvar0, argptr, bltinlookup("IFS"), /* can be NULL */ read_flags, opt_n, opt_p, opt_t, opt_u ); INT_ON; if ((uintptr_t)r == 1 && errno == EINTR) { /* to get SIGCHLD: sleep 1 & read x; echo $x */ if (pending_sig == 0) goto again; } if ((uintptr_t)r > 1) ash_msg_and_raise_error(r); return (uintptr_t)r; } static int FAST_FUNC umaskcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) { static const char permuser[3] ALIGN1 = "ogu"; mode_t mask; int symbolic_mode = 0; while (nextopt("S") != '\0') { symbolic_mode = 1; } INT_OFF; mask = umask(0); umask(mask); INT_ON; if (*argptr == NULL) { if (symbolic_mode) { char buf[sizeof(",u=rwx,g=rwx,o=rwx")]; char *p = buf; int i; i = 2; for (;;) { *p++ = ','; *p++ = permuser[i]; *p++ = '='; /* mask is 0..0uuugggooo. i=2 selects uuu bits */ if (!(mask & 0400)) *p++ = 'r'; if (!(mask & 0200)) *p++ = 'w'; if (!(mask & 0100)) *p++ = 'x'; mask <<= 3; if (--i < 0) break; } *p = '\0'; puts(buf + 1); } else { out1fmt("%04o\n", mask); } } else { char *modestr = *argptr; /* numeric umasks are taken as-is */ /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */ if (!isdigit(modestr[0])) mask ^= 0777; mask = bb_parse_mode(modestr, mask); if ((unsigned)mask > 0777) { ash_msg_and_raise_error("illegal mode: %s", modestr); } if (!isdigit(modestr[0])) mask ^= 0777; umask(mask); } return 0; } static int FAST_FUNC ulimitcmd(int argc UNUSED_PARAM, char **argv) { return shell_builtin_ulimit(argv); } /* ============ main() and helpers */ /* * Called to exit the shell. */ static void exitshell(void) { struct jmploc loc; char *p; int status; #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT save_history(line_input_state); #endif status = exitstatus; TRACE(("pid %d, exitshell(%d)\n", getpid(), status)); if (setjmp(loc.loc)) { if (exception_type == EXEXIT) status = exitstatus; goto out; } exception_handler = &loc; p = trap[0]; if (p) { trap[0] = NULL; evalskip = 0; evalstring(p, 0); /*free(p); - we'll exit soon */ } out: /* dash wraps setjobctl(0) in "if (setjmp(loc.loc) == 0) {...}". * our setjobctl(0) does not panic if tcsetpgrp fails inside it. */ setjobctl(0); flush_stdout_stderr(); _exit(status); /* NOTREACHED */ } static void init(void) { /* we will never free this */ basepf.next_to_pgetc = basepf.buf = ckmalloc(IBUFSIZ); sigmode[SIGCHLD - 1] = S_DFL; setsignal(SIGCHLD); /* bash re-enables SIGHUP which is SIG_IGNed on entry. * Try: "trap '' HUP; bash; echo RET" and type "kill -HUP $$" */ signal(SIGHUP, SIG_DFL); { char **envp; const char *p; struct stat st1, st2; initvar(); for (envp = environ; envp && *envp; envp++) { p = endofname(*envp); if (p != *envp && *p == '=') { setvareq(*envp, VEXPORT|VTEXTFIXED); } } setvareq((char*)defoptindvar, VTEXTFIXED); setvar0("PPID", utoa(getppid())); #if BASH_SHLVL_VAR p = lookupvar("SHLVL"); setvar("SHLVL", utoa((p ? atoi(p) : 0) + 1), VEXPORT); #endif #if BASH_HOSTNAME_VAR if (!lookupvar("HOSTNAME")) { struct utsname uts; uname(&uts); setvar0("HOSTNAME", uts.nodename); } #endif p = lookupvar("PWD"); if (p) { if (p[0] != '/' || stat(p, &st1) || stat(".", &st2) || st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino ) { p = NULL; } } setpwd(p, 0); } } //usage:#define ash_trivial_usage //usage: "[-/+OPTIONS] [-/+o OPT]... [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]" //usage:#define ash_full_usage "\n\n" //usage: "Unix shell interpreter" /* * Process the shell command line arguments. */ static void procargs(char **argv) { int i; const char *xminusc; char **xargv; xargv = argv; arg0 = xargv[0]; /* if (xargv[0]) - mmm, this is always true! */ xargv++; for (i = 0; i < NOPTS; i++) optlist[i] = 2; argptr = xargv; if (options(/*cmdline:*/ 1)) { /* it already printed err message */ raise_exception(EXERROR); } xargv = argptr; xminusc = minusc; if (*xargv == NULL) { if (xminusc) ash_msg_and_raise_error(bb_msg_requires_arg, "-c"); sflag = 1; } if (iflag == 2 && sflag == 1 && isatty(0) && isatty(1)) iflag = 1; if (mflag == 2) mflag = iflag; for (i = 0; i < NOPTS; i++) if (optlist[i] == 2) optlist[i] = 0; #if DEBUG == 2 debug = 1; #endif /* POSIX 1003.2: first arg after "-c CMD" is $0, remainder $1... */ if (xminusc) { minusc = *xargv++; if (*xargv) goto setarg0; } else if (!sflag) { setinputfile(*xargv, 0); setarg0: arg0 = *xargv++; commandname = arg0; } shellparam.p = xargv; #if ENABLE_ASH_GETOPTS shellparam.optind = 1; shellparam.optoff = -1; #endif /* assert(shellparam.malloced == 0 && shellparam.nparam == 0); */ while (*xargv) { shellparam.nparam++; xargv++; } optschanged(); } /* * Read /etc/profile, ~/.profile, $ENV. */ static void read_profile(const char *name) { name = expandstr(name); if (setinputfile(name, INPUT_PUSH_FILE | INPUT_NOFILE_OK) < 0) return; cmdloop(0); popfile(); } /* * This routine is called when an error or an interrupt occurs in an * interactive shell and control is returned to the main command loop. * (In dash, this function is auto-generated by build machinery). */ static void reset(void) { /* from eval.c: */ evalskip = 0; loopnest = 0; /* from expand.c: */ ifsfree(); /* from input.c: */ g_parsefile->left_in_buffer = 0; g_parsefile->left_in_line = 0; /* clear input buffer */ popallfiles(); /* from redir.c: */ while (redirlist) popredir(/*drop:*/ 0, /*restore:*/ 0); } #if PROFILE static short profile_buf[16384]; extern int etext(); #endif /* * Main routine. We initialize things, parse the arguments, execute * profiles if we're a login shell, and then call cmdloop to execute * commands. The setjmp call sets up the location to jump to when an * exception occurs. When an exception occurs the variable "state" * is used to figure out how far we had gotten. */ int ash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int ash_main(int argc UNUSED_PARAM, char **argv) { volatile smallint state; struct jmploc jmploc; struct stackmark smark; /* Initialize global data */ INIT_G_misc(); INIT_G_memstack(); INIT_G_var(); #if ENABLE_ASH_ALIAS INIT_G_alias(); #endif INIT_G_cmdtable(); #if PROFILE monitor(4, etext, profile_buf, sizeof(profile_buf), 50); #endif #if ENABLE_FEATURE_EDITING line_input_state = new_line_input_t(FOR_SHELL | WITH_PATH_LOOKUP); #endif state = 0; if (setjmp(jmploc.loc)) { smallint e; smallint s; reset(); e = exception_type; s = state; if (e == EXEXIT || s == 0 || iflag == 0 || shlvl) { exitshell(); } if (e == EXINT) { newline_and_flush(stderr); } popstackmark(&smark); FORCE_INT_ON; /* enable interrupts */ if (s == 1) goto state1; if (s == 2) goto state2; if (s == 3) goto state3; goto state4; } exception_handler = &jmploc; rootpid = getpid(); init(); setstackmark(&smark); procargs(argv); #if DEBUG TRACE(("Shell args: ")); trace_puts_args(argv); #endif if (argv[0] && argv[0][0] == '-') isloginsh = 1; if (isloginsh) { const char *hp; state = 1; read_profile("/etc/profile"); state1: state = 2; hp = lookupvar("HOME"); if (hp) read_profile("$HOME/.profile"); } state2: state = 3; if ( #ifndef linux getuid() == geteuid() && getgid() == getegid() && #endif iflag ) { const char *shinit = lookupvar("ENV"); if (shinit != NULL && *shinit != '\0') read_profile(shinit); } popstackmark(&smark); state3: state = 4; if (minusc) { /* evalstring pushes parsefile stack. * Ensure we don't falsely claim that 0 (stdin) * is one of stacked source fds. * Testcase: ash -c 'exec 1>&0' must not complain. */ // if (!sflag) g_parsefile->pf_fd = -1; // ^^ not necessary since now we special-case fd 0 // in is_hidden_fd() to not be considered "hidden fd" evalstring(minusc, 0); } if (sflag || minusc == NULL) { #if MAX_HISTORY > 0 && ENABLE_FEATURE_EDITING_SAVEHISTORY if (iflag) { const char *hp = lookupvar("HISTFILE"); if (!hp) { hp = lookupvar("HOME"); if (hp) { INT_OFF; hp = concat_path_file(hp, ".ash_history"); setvar0("HISTFILE", hp); free((char*)hp); INT_ON; hp = lookupvar("HISTFILE"); } } if (hp) line_input_state->hist_file = hp; # if ENABLE_FEATURE_SH_HISTFILESIZE hp = lookupvar("HISTFILESIZE"); line_input_state->max_history = size_from_HISTFILESIZE(hp); # endif } #endif state4: /* XXX ??? - why isn't this before the "if" statement */ cmdloop(1); } #if PROFILE monitor(0); #endif #ifdef GPROF { extern void _mcleanup(void); _mcleanup(); } #endif TRACE(("End of main reached\n")); exitshell(); /* NOTREACHED */ } /*- * Copyright (c) 1989, 1991, 1993, 1994 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Kenneth Almquist. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */