/* 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-$(CONFIG_XARGS) += xargs.o
-
//config:config XARGS
//config: bool "xargs"
//config: default y
//config: Support -0: input items are terminated by a NUL character
//config: instead of whitespace, and the quotes and backslash
//config: are not special.
+//config:
+//config:config FEATURE_XARGS_SUPPORT_REPL_STR
+//config: bool "Enable -I STR: string to replace"
+//config: default y
+//config: depends on XARGS
+//config: help
+//config: Support -I STR and -i[STR] options.
+
+//applet:IF_XARGS(APPLET_NOEXEC(xargs, xargs, BB_DIR_USR_BIN, BB_SUID_DROP, xargs))
+
+//kbuild:lib-$(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
+#include "common_bufsiz.h"
/* This is a NOEXEC applet. Be very careful! */
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 { } while (0)
+#define G (*(struct globals*)bb_common_bufsiz1)
+#define INIT_G() do { \
+ setup_common_bufsiz(); \
+ 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;
return 124;
}
if (status >= 0x180) {
- bb_error_msg("%s: terminated by signal %d",
+ bb_error_msg("'%s' terminated by signal %d",
G.args[0], status - 0x180);
return 125;
}
* is seen, store the address of a new parameter to args[].
* If reading discovers that last chars do not form the complete
* parameter, the pointer to the first such "tail character" is returned.
- * (buf has extra byte at the end to accomodate terminating NUL
+ * (buf has extra byte at the end to accommodate terminating NUL
* of "tail characters" string).
* Otherwise, the returned pointer points to NUL byte.
* On entry, buf[] may contain some "seed chars" which are to become
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);
}
#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, buf);
+ 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;
# 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_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: )
+//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,
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 ,
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)
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
INIT_G();
- G.eof_str = NULL;
- opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &G.eof_str, &G.eof_str);
+#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
+ 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:
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;
argc++;
}
- /* The Open Group Base Specifications Issue 6:
+ /*
+ * 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.
+ n_max_chars = bb_arg_max();
+ if (n_max_chars > 32 * 1024)
+ n_max_chars = 32 * 1024;
+ /*
+ * POSIX suggests substracting 2048 bytes from sysconf(_SC_ARG_MAX)
+ * so that the process may safely modify its environment.
*/
- if (n_max_chars > 20 * 1024)
- n_max_chars = 20 * 1024;
+ n_max_chars -= 2048;
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 */
- /* 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;
+ /* Make -I imply -r. GNU findutils seems to do the same: */
+ /* (otherwise "echo -n | xargs -I% echo %" would SEGV) */
+ opt |= OPT_NO_EMPTY;
+ } 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;