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xargs: add support for -I and -i. Closes 493

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function                                             old     new   delta
process_stdin_with_replace                             -     195    +195
xmalloc_substitute_string                              -     145    +145
xargs_main                                           808     884     +76
count_strstr                                           -      45     +45
packed_usage                                       29580   29571      -9
parse_params                                        1445    1416     -29
func_exec                                            285     138    -147
------------------------------------------------------------------------------
(add/remove: 4/0 grow/shrink: 1/3 up/down: 461/-185)          Total: 276 bytes
   text	   data	    bss	    dec	    hex	filename
 922156	    932	  17692	 940780	  e5aec	busybox_old
 922440	    932	  17692	 941064	  e5c08	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2014-02-27 11:17:06 +01:00
parent 6885e49ba5
commit 6f068904dc
4 changed files with 176 additions and 56 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
findutils/find.c
View File

@ -402,34 +402,6 @@ struct globals {
G.recurse_flags = ACTION_RECURSE; \
} while (0)
#if ENABLE_FEATURE_FIND_EXEC
static unsigned count_subst(const char *str)
{
unsigned count = 0;
while ((str = strstr(str, "{}")) != NULL) {
count++;
str++;
}
return count;
}
static char* subst(const char *src, unsigned count, const char* filename)
{
char *buf, *dst, *end;
size_t flen = strlen(filename);
/* we replace each '{}' with filename: growth by strlen-2 */
buf = dst = xmalloc(strlen(src) + count*(flen-2) + 1);
while ((end = strstr(src, "{}")) != NULL) {
dst = mempcpy(dst, src, end - src);
dst = mempcpy(dst, filename, flen);
src = end + 2;
}
strcpy(dst, src);
return buf;
}
#endif
/* Return values of ACTFs ('action functions') are a bit mask:
* bit 1=1: prune (use SKIP constant for setting it)
* bit 0=1: matched successfully (TRUE)
@ -613,7 +585,7 @@ ACTF(exec)
char *argv[ap->exec_argc + 1];
#endif
for (i = 0; i < ap->exec_argc; i++)
argv[i] = subst(ap->exec_argv[i], ap->subst_count[i], fileName);
argv[i] = xmalloc_substitute_string(ap->exec_argv[i], ap->subst_count[i], "{}", fileName);
argv[i] = NULL; /* terminate the list */
rc = spawn_and_wait(argv);
@ -1091,7 +1063,7 @@ static action*** parse_params(char **argv)
ap->subst_count = xmalloc(ap->exec_argc * sizeof(int));
i = ap->exec_argc;
while (i--)
ap->subst_count[i] = count_subst(ap->exec_argv[i]);
ap->subst_count[i] = count_strstr(ap->exec_argv[i], "{}");
}
#endif
#if ENABLE_FEATURE_FIND_PAREN

153
findutils/xargs.c
View File

@ -53,6 +53,13 @@
//config: Support -0: input items are terminated by a NUL character
//config: instead of whitespace, and the quotes and backslash
//config: are not special.
//config:
//config:config FEATURE_XARGS_SUPPORT_REPL_STR
//config: bool "Enable -I STR: string to replace"
//config: default y
//config: depends on XARGS
//config: help
//config: Support -I STR and -i[STR] options.
//applet:IF_XARGS(APPLET_NOEXEC(xargs, xargs, BB_DIR_USR_BIN, BB_SUID_DROP, xargs))
@ -85,19 +92,22 @@
struct globals {
char **args;
#if ENABLE_FEATURE_XARGS_SUPPORT_REPL_STR
char **argv;
const char *repl_str;
char eol_ch;
#endif
const char *eof_str;
int idx;
} FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1)
#define INIT_G() do { \
G.eof_str = NULL; /* need to clear by hand because we are NOEXEC applet */ \
IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.repl_str = "{}";) \
IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.eol_ch = '\n';) \
} while (0)
/*
* This function has special algorithm.
* Don't use fork and include to main!
*/
static int xargs_exec(void)
{
int status;
@ -301,7 +311,7 @@ static char* FAST_FUNC process0_stdin(int n_max_chars, int n_max_arg, char *buf)
c = '\0';
}
*p++ = c;
if (c == '\0') { /* word's delimiter or EOF detected */
if (c == '\0') { /* NUL or EOF detected */
/* A full word is loaded */
store_param(s);
dbg_msg("args[]:'%s'", s);
@ -323,10 +333,71 @@ static char* FAST_FUNC process0_stdin(int n_max_chars, int n_max_arg, char *buf)
}
#endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */
#if ENABLE_FEATURE_XARGS_SUPPORT_REPL_STR
/*
* Used if -I<repl> was specified.
* In this mode, words aren't appended to PROG ARGS.
* Instead, entire input line is read, then <repl> string
* in every PROG and ARG is replaced with the line:
* echo -e "ho ho\nhi" | xargs -I_ cmd __ _
* results in "cmd 'ho hoho ho' 'ho ho'"; "cmd 'hihi' 'hi'".
* -n MAX_ARGS seems to be ignored.
* Tested with GNU findutils 4.5.10.
*/
//FIXME: n_max_chars is not handled the same way as in GNU findutils.
//FIXME: quoting is not implemented.
static char* FAST_FUNC process_stdin_with_replace(int n_max_chars, int n_max_arg UNUSED_PARAM, char *buf)
{
int i;
char *end, *p;
/* Free strings from last invocation, if any */
for (i = 0; G.args && G.args[i]; i++)
if (G.args[i] != G.argv[i])
free(G.args[i]);
end = buf + n_max_chars;
p = buf;
while (1) {
int c = getchar();
if (c == EOF || c == G.eol_ch) {
if (p == buf)
goto ret; /* empty line */
c = '\0';
}
*p++ = c;
if (c == '\0') { /* EOL or EOF detected */
i = 0;
while (G.argv[i]) {
char *arg = G.argv[i];
int count = count_strstr(arg, G.repl_str);
if (count != 0)
arg = xmalloc_substitute_string(arg, count, G.repl_str, s);
store_param(arg);
dbg_msg("args[]:'%s'", arg);
i++;
}
p = buf;
goto ret;
}
if (p == end) {
goto ret;
}
}
ret:
*p = '\0';
/* store_param(NULL) - caller will do it */
dbg_msg("return:'%s'", buf);
return buf;
}
#endif
#if ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION
/* Prompt the user for a response, and
if the user responds affirmatively, return true;
otherwise, return false. Uses "/dev/tty", not stdin. */
* if user responds affirmatively, return true;
* otherwise, return false. Uses "/dev/tty", not stdin.
*/
static int xargs_ask_confirmation(void)
{
FILE *tty_stream;
@ -360,6 +431,9 @@ static int xargs_ask_confirmation(void)
//usage: "\n -e[STR] STR stops input processing"
//usage: "\n -n N Pass no more than N args to PROG"
//usage: "\n -s N Pass command line of no more than N bytes"
//usage: IF_FEATURE_XARGS_SUPPORT_REPL_STR(
//usage: "\n -I STR Replace STR within PROG ARGS with input line"
//usage: )
//usage: IF_FEATURE_XARGS_SUPPORT_TERMOPT(
//usage: "\n -x Exit if size is exceeded"
//usage: )
@ -378,6 +452,8 @@ enum {
IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
IF_FEATURE_XARGS_SUPPORT_TERMOPT( OPTBIT_TERMINATE ,)
IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( OPTBIT_ZEROTERM ,)
IF_FEATURE_XARGS_SUPPORT_REPL_STR( OPTBIT_REPLSTR ,)
IF_FEATURE_XARGS_SUPPORT_REPL_STR( OPTBIT_REPLSTR1 ,)
OPT_VERBOSE = 1 << OPTBIT_VERBOSE ,
OPT_NO_EMPTY = 1 << OPTBIT_NO_EMPTY ,
@ -388,11 +464,14 @@ enum {
OPT_INTERACTIVE = IF_FEATURE_XARGS_SUPPORT_CONFIRMATION((1 << OPTBIT_INTERACTIVE)) + 0,
OPT_TERMINATE = IF_FEATURE_XARGS_SUPPORT_TERMOPT( (1 << OPTBIT_TERMINATE )) + 0,
OPT_ZEROTERM = IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( (1 << OPTBIT_ZEROTERM )) + 0,
OPT_REPLSTR = IF_FEATURE_XARGS_SUPPORT_REPL_STR( (1 << OPTBIT_REPLSTR )) + 0,
OPT_REPLSTR1 = IF_FEATURE_XARGS_SUPPORT_REPL_STR( (1 << OPTBIT_REPLSTR1 )) + 0,
};
#define OPTION_STR "+trn:s:e::E:" \
IF_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \
IF_FEATURE_XARGS_SUPPORT_TERMOPT( "x") \
IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( "0")
IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( "0") \
IF_FEATURE_XARGS_SUPPORT_REPL_STR( "I:i::")
int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int xargs_main(int argc, char **argv)
@ -405,7 +484,8 @@ int xargs_main(int argc, char **argv)
unsigned opt;
int n_max_chars;
int n_max_arg;
#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM \
|| ENABLE_FEATURE_XARGS_SUPPORT_REPL_STR
char* FAST_FUNC (*read_args)(int, int, char*) = process_stdin;
#else
#define read_args process_stdin
@ -419,7 +499,10 @@ int xargs_main(int argc, char **argv)
"no-run-if-empty\0" No_argument "r"
;
#endif
opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &G.eof_str, &G.eof_str);
opt = getopt32(argv, OPTION_STR,
&max_args, &max_chars, &G.eof_str, &G.eof_str
IF_FEATURE_XARGS_SUPPORT_REPL_STR(, &G.repl_str, &G.repl_str)
);
/* -E ""? You may wonder why not just omit -E?
* This is used for portability:
@ -427,8 +510,10 @@ int xargs_main(int argc, char **argv)
if ((opt & OPT_EOF_STRING1) && G.eof_str[0] == '\0')
G.eof_str = NULL;
if (opt & OPT_ZEROTERM)
IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
if (opt & OPT_ZEROTERM) {
IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin;)
IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.eol_ch = '\0';)
}
argv += optind;
argc -= optind;
@ -486,20 +571,36 @@ int xargs_main(int argc, char **argv)
/* if (n_max_arg > n_max_chars) n_max_arg = n_max_chars */
}
/* Allocate pointers for execvp */
/* We can statically allocate (argc + n_max_arg + 1) elements
* and do not bother with resizing args[], but on 64-bit machines
* this results in args[] vector which is ~8 times bigger
* than n_max_chars! That is, with n_max_chars == 20k,
* args[] will take 160k (!), which will most likely be
* almost entirely unused.
*/
/* See store_param() for matching 256-step growth logic */
G.args = xmalloc(sizeof(G.args[0]) * ((argc + 0xff) & ~0xff));
/* Store the command to be executed, part 1 */
for (i = 0; argv[i]; i++)
G.args[i] = argv[i];
#if ENABLE_FEATURE_XARGS_SUPPORT_REPL_STR
if (opt & (OPT_REPLSTR | OPT_REPLSTR1)) {
/*
* -I<str>:
* Unmodified args are kept in G.argv[i],
* G.args[i] receives malloced G.argv[i] with <str> replaced
* with input line. Setting this up:
*/
G.args = NULL;
G.argv = argv;
argc = 0;
read_args = process_stdin_with_replace;
} else
#endif
{
/* Allocate pointers for execvp.
* We can statically allocate (argc + n_max_arg + 1) elements
* and do not bother with resizing args[], but on 64-bit machines
* this results in args[] vector which is ~8 times bigger
* than n_max_chars! That is, with n_max_chars == 20k,
* args[] will take 160k (!), which will most likely be
* almost entirely unused.
*
* See store_param() for matching 256-step growth logic
*/
G.args = xmalloc(sizeof(G.args[0]) * ((argc + 0xff) & ~0xff));
/* Store the command to be executed, part 1 */
for (i = 0; argv[i]; i++)
G.args[i] = argv[i];
}
while (1) {
char *rem;

2
include/libbb.h
View File

@ -650,6 +650,8 @@ char *xstrndup(const char *s, int n) FAST_FUNC RETURNS_MALLOC;
void overlapping_strcpy(char *dst, const char *src) FAST_FUNC;
char *safe_strncpy(char *dst, const char *src, size_t size) FAST_FUNC;
char *strncpy_IFNAMSIZ(char *dst, const char *src) FAST_FUNC;
unsigned count_strstr(const char *str, const char *sub) FAST_FUNC;
char *xmalloc_substitute_string(const char *src, int count, const char *sub, const char *repl) FAST_FUNC;
/* Guaranteed to NOT be a macro (smallest code). Saves nearly 2k on uclibc.
* But potentially slow, don't use in one-billion-times loops */
int bb_putchar(int ch) FAST_FUNC;

45
libbb/replace.c Normal file
View File

@ -0,0 +1,45 @@
/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//kbuild:lib-y += replace.o
#include "libbb.h"
unsigned FAST_FUNC count_strstr(const char *str, const char *sub)
{
size_t sub_len = strlen(sub);
unsigned count = 0;
while ((str = strstr(str, sub)) != NULL) {
count++;
str += sub_len;
}
return count;
}
char* FAST_FUNC xmalloc_substitute_string(const char *src, int count, const char *sub, const char *repl)
{
char *buf, *dst, *end;
size_t sub_len = strlen(sub);
size_t repl_len = strlen(repl);
//dbg_msg("subst(s:'%s',count:%d,sub:'%s',repl:'%s'", src, count, sub, repl);
buf = dst = xmalloc(strlen(src) + count * ((int)repl_len - (int)sub_len) + 1);
/* we replace each sub with repl */
while ((end = strstr(src, sub)) != NULL) {
dst = mempcpy(dst, src, end - src);
dst = mempcpy(dst, repl, repl_len);
/*src = end + 1; - GNU findutils 4.5.10 doesn't do this... */
src = end + sub_len; /* but this. Try "xargs -Iaa echo aaa" */
}
strcpy(dst, src);
//dbg_msg("subst9:'%s'", buf);
return buf;
}