/* vi: set sw=4 ts=4: */
/*
* Mini xargs implementation for busybox
- * Options are supported: "-prtx -n max_arg -s max_chars -e[ouf_str]"
*
* (C) 2002,2003 by Vladimir Oleynik <dzo@simtreas.ru>
*
* - Mike Rendell <michael@cs.mun.ca>
* and David MacKenzie <djm@gnu.ai.mit.edu>.
*
- * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*
* xargs is described in the Single Unix Specification v3 at
* http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html
- *
*/
-//kbuild:lib-$(CONFIG_XARGS) += xargs.o
-//config:
//config:config XARGS
//config: bool "xargs"
//config: default y
//config: instead of whitespace, and the quotes and backslash
//config: are not special.
+//applet:IF_XARGS(APPLET_NOEXEC(xargs, xargs, BB_DIR_USR_BIN, BB_SUID_DROP, xargs))
+
+//kbuild:lib-$(CONFIG_XARGS) += xargs.o
+
#include "libbb.h"
-/* COMPAT: SYSV version defaults size (and has a max value of) to 470.
- We try to make it as large as possible. */
-#if !defined(ARG_MAX) && defined(_SC_ARG_MAX)
-# define ARG_MAX sysconf(_SC_ARG_MAX)
-#endif
-#if !defined(ARG_MAX)
-# define ARG_MAX 470
-#endif
/* This is a NOEXEC applet. Be very careful! */
int idx;
} FIX_ALIASING;
#define G (*(struct globals*)&bb_common_bufsiz1)
-#define INIT_G() do { } while (0)
+#define INIT_G() do { \
+ G.eof_str = NULL; /* need to clear by hand because we are NOEXEC applet */ \
+} while (0)
/*
#define QUOTE 1
#define BACKSLASH 2
#define SPACE 4
- char *s; /* start of the word */
- char *p; /* pointer to end of the word */
- char q = '\0'; /* quote char */
+ char q = '\0'; /* quote char */
char state = NORM;
+ char *s = buf; /* start of the word */
+ char *p = s + strlen(buf); /* end of the word */
- s = buf;
- p = s + strlen(buf);
+ buf += n_max_chars; /* past buffer's end */
/* "goto ret" is used instead of "break" to make control flow
* more obvious: */
goto ret;
}
}
- n_max_chars -= (p - s);
- /* if (n_max_chars < 0) impossible */
store_param(s);
dbg_msg("args[]:'%s'", s);
s = p;
n_max_arg--;
- if (n_max_arg == 0 || n_max_chars == 0) {
+ if (n_max_arg == 0) {
goto ret;
}
state = NORM;
- } else /* state != SPACE */
- if (p - s >= n_max_chars) {
- dbg_msg("s:'%s' p-s:%d n_max_chars:%d", s, (int)(p-s), n_max_chars);
+ }
+ if (p == buf) {
goto ret;
}
}
/* The variant does not support single quotes, double quotes or backslash */
static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
{
- char *s; /* start of the word */
- char *p; /* pointer to end of the word */
+ char *s = buf; /* start of the word */
+ char *p = s + strlen(buf); /* end of the word */
- s = buf;
- p = s + strlen(buf);
+ buf += n_max_chars; /* past buffer's end */
while (1) {
int c = getchar();
goto ret;
}
}
- n_max_chars -= (p - s);
- /* if (n_max_chars < 0) impossible */
store_param(s);
dbg_msg("args[]:'%s'", s);
s = p;
n_max_arg--;
- if (n_max_arg == 0 || n_max_chars == 0) {
+ if (n_max_arg == 0) {
goto ret;
}
- } else /* c != EOF */
- if (p - s >= n_max_chars) {
+ }
+ if (p == buf) {
goto ret;
}
}
#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
static char* FAST_FUNC process0_stdin(int n_max_chars, int n_max_arg, char *buf)
{
- char *s; /* start of the word */
- char *p; /* pointer to end of the word */
+ char *s = buf; /* start of the word */
+ char *p = s + strlen(buf); /* end of the word */
- s = buf;
- p = s + strlen(buf);
+ buf += n_max_chars; /* past buffer's end */
while (1) {
int c = getchar();
*p++ = c;
if (c == '\0') { /* word's delimiter or EOF detected */
/* A full word is loaded */
- n_max_chars -= (p - s);
- /* if (n_max_chars < 0) impossible */
store_param(s);
dbg_msg("args[]:'%s'", s);
- n_max_arg--;
s = p;
- if (n_max_arg == 0 || n_max_chars == 0) {
+ n_max_arg--;
+ if (n_max_arg == 0) {
goto ret;
}
- } else /* c != '\0' */
- if (p - s >= n_max_chars) {
+ }
+ if (p == buf) {
goto ret;
}
}
# define xargs_ask_confirmation() 1
#endif
+//usage:#define xargs_trivial_usage
+//usage: "[OPTIONS] [PROG ARGS]"
+//usage:#define xargs_full_usage "\n\n"
+//usage: "Run PROG on every item given by stdin\n"
+//usage: IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(
+//usage: "\n -p Ask user whether to run each command"
+//usage: )
+//usage: "\n -r Don't run command if input is empty"
+//usage: IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(
+//usage: "\n -0 Input is separated by NUL characters"
+//usage: )
+//usage: "\n -t Print the command on stderr before execution"
+//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_TERMOPT(
+//usage: "\n -x Exit if size is exceeded"
+//usage: )
+//usage:#define xargs_example_usage
+//usage: "$ ls | xargs gzip\n"
+//usage: "$ find . -name '*.c' -print | xargs rm\n"
+
/* Correct regardless of combination of CONFIG_xxx */
enum {
OPTBIT_VERBOSE = 0,
INIT_G();
- G.eof_str = NULL;
+#if ENABLE_DESKTOP && ENABLE_LONG_OPTS
+ /* For example, Fedora's build system uses --no-run-if-empty */
+ applet_long_options =
+ "no-run-if-empty\0" No_argument "r"
+ ;
+#endif
opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &G.eof_str, &G.eof_str);
/* -E ""? You may wonder why not just omit -E?
argc++;
}
- /* The Open Group Base Specifications Issue 6:
+ /* -s NUM default. fileutils-4.4.2 uses 128k, but I heasitate
+ * to use such a big value - first need to change code to use
+ * growable buffer instead of fixed one.
+ */
+ n_max_chars = 32 * 1024;
+ /* Make smaller if system does not allow our default value.
+ * The Open Group Base Specifications Issue 6:
* "The xargs utility shall limit the command line length such that
* when the command line is invoked, the combined argument
* and environment lists (see the exec family of functions
* in the System Interfaces volume of IEEE Std 1003.1-2001)
* shall not exceed {ARG_MAX}-2048 bytes".
*/
- n_max_chars = ARG_MAX; /* might be calling sysconf(_SC_ARG_MAX) */
- if (n_max_chars < 4*1024); /* paranoia */
- n_max_chars = 4*1024;
- n_max_chars -= 2048;
- /* Sanity check for systems with huge ARG_MAX defines (e.g., Suns which
- * have it at 1 meg). Things will work fine with a large ARG_MAX
- * but it will probably hurt the system more than it needs to;
- * an array of this size is allocated.
- */
- if (n_max_chars > 20 * 1024)
- n_max_chars = 20 * 1024;
-
+ {
+ long arg_max = 0;
+#if defined _SC_ARG_MAX
+ arg_max = sysconf(_SC_ARG_MAX) - 2048;
+#elif defined ARG_MAX
+ arg_max = ARG_MAX - 2048;
+#endif
+ if (arg_max > 0 && n_max_chars > arg_max)
+ n_max_chars = arg_max;
+ }
if (opt & OPT_UPTO_SIZE) {
- size_t n_chars = 0;
n_max_chars = xatou_range(max_chars, 1, INT_MAX);
+ }
+ /* Account for prepended fixed arguments */
+ {
+ size_t n_chars = 0;
for (i = 0; argv[i]; i++) {
n_chars += strlen(argv[i]) + 1;
}
n_max_chars -= n_chars;
- if (n_max_chars <= 0) {
- bb_error_msg_and_die("can't fit single argument within argument list size limit");
- }
+ }
+ /* Sanity check */
+ if (n_max_chars <= 0) {
+ bb_error_msg_and_die("can't fit single argument within argument list size limit");
}
buf = xzalloc(n_max_chars + 1);
n_max_arg = n_max_chars;
if (opt & OPT_UPTO_NUMBER) {
n_max_arg = xatou_range(max_args, 1, INT_MAX);
+ /* Not necessary, we use growable args[]: */
+ /* if (n_max_arg > n_max_chars) n_max_arg = n_max_chars */
}
/* Allocate pointers for execvp */
projects / oweals / busybox.git / blobdiff