-/* minix xargs - Make and execute commands
- * Author: Ian Nicholls: 1 Mar 90 */
-
+/* vi: set sw=4 ts=4: */
/*
- * xargs - Accept words from stdin until, combined with the arguments
- * given on the command line, just fit into the command line limit.
- * Then, execute the result.
- * e.g. ls | xargs compress
- * find . -name '*.s' -print | xargs ar qv libc.a
+ * Mini xargs implementation for busybox
*
- * flags: -t Print the command just before it is run
- * -l len Use len as maximum line length (default 490, max 1023)
- * -e ending Append ending to the command before executing it.
+ * (C) 2002,2003 by Vladimir Oleynik <dzo@simtreas.ru>
*
- * Exits with: 0 No errors.
- * 1 If any system(3) call returns a nonzero status.
- * 2 Usage error
- * 3 Line length too short to contain some single argument.
+ * Special thanks
+ * - Mark Whitley and Glenn McGrath for stimulus to rewrite :)
+ * - Mike Rendell <michael@cs.mun.ca>
+ * and David MacKenzie <djm@gnu.ai.mit.edu>.
*
- * Examples: xargs ar qv libc.a < liborder # Create a new libc.a
- * find . -name '*.s' -print | xargs rm # Remove all .s files
- * find . -type f ! -name '*.Z' \ # Compress old files.
- * -atime +60 -print | xargs compress -v
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*
- * Bugs: If the command contains unquoted wildflags, then the system(3) call
- * call may expand this to larger than the maximum line size.
- * The command is not executed if nothing was read from stdin.
- * xargs may give up too easily when the command returns nonzero.
+ * xargs is described in the Single Unix Specification v3 at
+ * http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html
+ */
+
+//config:config XARGS
+//config: bool "xargs"
+//config: default y
+//config: help
+//config: xargs is used to execute a specified command for
+//config: every item from standard input.
+//config:
+//config:config FEATURE_XARGS_SUPPORT_CONFIRMATION
+//config: bool "Enable -p: prompt and confirmation"
+//config: default y
+//config: depends on XARGS
+//config: help
+//config: Support -p: prompt the user whether to run each command
+//config: line and read a line from the terminal.
+//config:
+//config:config FEATURE_XARGS_SUPPORT_QUOTES
+//config: bool "Enable single and double quotes and backslash"
+//config: default y
+//config: depends on XARGS
+//config: help
+//config: Support quoting in the input.
+//config:
+//config:config FEATURE_XARGS_SUPPORT_TERMOPT
+//config: bool "Enable -x: exit if -s or -n is exceeded"
+//config: default y
+//config: depends on XARGS
+//config: help
+//config: Support -x: exit if the command size (see the -s or -n option)
+//config: is exceeded.
+//config:
+//config:config FEATURE_XARGS_SUPPORT_ZERO_TERM
+//config: bool "Enable -0: NUL-terminated input"
+//config: default y
+//config: depends on XARGS
+//config: help
+//config: Support -0: input items are terminated by a NUL character
+//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"
+
+/* This is a NOEXEC applet. Be very careful! */
+
+
+//#define dbg_msg(...) bb_error_msg(__VA_ARGS__)
+#define dbg_msg(...) ((void)0)
+
+
+#ifdef TEST
+# ifndef ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION
+# define ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION 1
+# endif
+# ifndef ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
+# define ENABLE_FEATURE_XARGS_SUPPORT_QUOTES 1
+# endif
+# ifndef ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT
+# define ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT 1
+# endif
+# ifndef ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
+# define ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM 1
+# endif
+#endif
+
+
+struct globals {
+ char **args;
+ 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 */ \
+} while (0)
+
+
+/*
+ * This function has special algorithm.
+ * Don't use fork and include to main!
+ */
+static int xargs_exec(void)
+{
+ int status;
+
+ status = spawn_and_wait(G.args);
+ if (status < 0) {
+ bb_simple_perror_msg(G.args[0]);
+ return errno == ENOENT ? 127 : 126;
+ }
+ if (status == 255) {
+ bb_error_msg("%s: exited with status 255; aborting", G.args[0]);
+ return 124;
+ }
+ if (status >= 0x180) {
+ bb_error_msg("%s: terminated by signal %d",
+ G.args[0], status - 0x180);
+ return 125;
+ }
+ if (status)
+ return 123;
+ return 0;
+}
+
+/* In POSIX/C locale isspace is only these chars: "\t\n\v\f\r" and space.
+ * "\t\n\v\f\r" happen to have ASCII codes 9,10,11,12,13.
+ */
+#define ISSPACE(a) ({ unsigned char xargs__isspace = (a) - 9; xargs__isspace == (' ' - 9) || xargs__isspace <= (13 - 9); })
+
+static void store_param(char *s)
+{
+ /* Grow by 256 elements at once */
+ if (!(G.idx & 0xff)) { /* G.idx == N*256 */
+ /* Enlarge, make G.args[(N+1)*256 - 1] last valid idx */
+ G.args = xrealloc(G.args, sizeof(G.args[0]) * (G.idx + 0x100));
+ }
+ G.args[G.idx++] = s;
+}
+
+/* process[0]_stdin:
+ * Read characters into buf[n_max_chars+1], and when parameter delimiter
+ * 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
+ * of "tail characters" string).
+ * Otherwise, the returned pointer points to NUL byte.
+ * On entry, buf[] may contain some "seed chars" which are to become
+ * the beginning of the first parameter.
*/
-#define USAGE "usage: xargs [-t] [-l len] [-e endargs] command [args...]\n"
-#include <errno.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdio.h>
-#include <getopt.h>
+#if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
+static char* FAST_FUNC process_stdin(int n_max_chars, int n_max_arg, char *buf)
+{
+#define NORM 0
+#define QUOTE 1
+#define BACKSLASH 2
+#define SPACE 4
+ char q = '\0'; /* quote char */
+ char state = NORM;
+ char *s = buf; /* start of the word */
+ char *p = s + strlen(buf); /* end of the word */
+
+ buf += n_max_chars; /* past buffer's end */
+
+ /* "goto ret" is used instead of "break" to make control flow
+ * more obvious: */
+
+ while (1) {
+ int c = getchar();
+ if (c == EOF) {
+ if (p != s)
+ goto close_word;
+ goto ret;
+ }
+ if (state == BACKSLASH) {
+ state = NORM;
+ goto set;
+ }
+ if (state == QUOTE) {
+ if (c != q)
+ goto set;
+ q = '\0';
+ state = NORM;
+ } else { /* if (state == NORM) */
+ if (ISSPACE(c)) {
+ if (p != s) {
+ close_word:
+ state = SPACE;
+ c = '\0';
+ goto set;
+ }
+ } else {
+ if (c == '\\') {
+ state = BACKSLASH;
+ } else if (c == '\'' || c == '"') {
+ q = c;
+ state = QUOTE;
+ } else {
+ set:
+ *p++ = c;
+ }
+ }
+ }
+ if (state == SPACE) { /* word's delimiter or EOF detected */
+ if (q) {
+ bb_error_msg_and_die("unmatched %s quote",
+ q == '\'' ? "single" : "double");
+ }
+ /* A full word is loaded */
+ if (G.eof_str) {
+ if (strcmp(s, G.eof_str) == 0) {
+ while (getchar() != EOF)
+ continue;
+ p = s;
+ goto ret;
+ }
+ }
+ store_param(s);
+ dbg_msg("args[]:'%s'", s);
+ s = p;
+ n_max_arg--;
+ if (n_max_arg == 0) {
+ goto ret;
+ }
+ state = NORM;
+ }
+ if (p == buf) {
+ goto ret;
+ }
+ }
+ ret:
+ *p = '\0';
+ /* store_param(NULL) - caller will do it */
+ dbg_msg("return:'%s'", s);
+ return s;
+}
+#else
+/* 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 = buf; /* start of the word */
+ char *p = s + strlen(buf); /* end of the word */
+
+ buf += n_max_chars; /* past buffer's end */
+
+ while (1) {
+ int c = getchar();
+ if (c == EOF) {
+ if (p == s)
+ goto ret;
+ }
+ if (c == EOF || ISSPACE(c)) {
+ if (p == s)
+ continue;
+ c = EOF;
+ }
+ *p++ = (c == EOF ? '\0' : c);
+ if (c == EOF) { /* word's delimiter or EOF detected */
+ /* A full word is loaded */
+ if (G.eof_str) {
+ if (strcmp(s, G.eof_str) == 0) {
+ while (getchar() != EOF)
+ continue;
+ p = s;
+ goto ret;
+ }
+ }
+ store_param(s);
+ dbg_msg("args[]:'%s'", s);
+ s = p;
+ n_max_arg--;
+ if (n_max_arg == 0) {
+ goto ret;
+ }
+ }
+ if (p == buf) {
+ goto ret;
+ }
+ }
+ ret:
+ *p = '\0';
+ /* store_param(NULL) - caller will do it */
+ dbg_msg("return:'%s'", s);
+ return s;
+}
+#endif /* FEATURE_XARGS_SUPPORT_QUOTES */
+
+#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 = buf; /* start of the word */
+ char *p = s + strlen(buf); /* end of the word */
+
+ buf += n_max_chars; /* past buffer's end */
+
+ while (1) {
+ int c = getchar();
+ if (c == EOF) {
+ if (p == s)
+ goto ret;
+ c = '\0';
+ }
+ *p++ = c;
+ if (c == '\0') { /* word's delimiter or EOF detected */
+ /* A full word is loaded */
+ store_param(s);
+ dbg_msg("args[]:'%s'", s);
+ s = p;
+ n_max_arg--;
+ if (n_max_arg == 0) {
+ goto ret;
+ }
+ }
+ if (p == buf) {
+ goto ret;
+ }
+ }
+ ret:
+ *p = '\0';
+ /* store_param(NULL) - caller will do it */
+ dbg_msg("return:'%s'", s);
+ return s;
+}
+#endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */
+
+#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. */
+static int xargs_ask_confirmation(void)
+{
+ FILE *tty_stream;
+ int c, savec;
-#ifndef MAX_ARGLINE
-# define MAX_ARGLINE 1023
+ tty_stream = xfopen_for_read(CURRENT_TTY);
+ fputs(" ?...", stderr);
+ fflush_all();
+ c = savec = getc(tty_stream);
+ while (c != EOF && c != '\n')
+ c = getc(tty_stream);
+ fclose(tty_stream);
+ return (savec == 'y' || savec == 'Y');
+}
+#else
+# define xargs_ask_confirmation() 1
#endif
-#ifndef min
-# define min(a,b) ((a) < (b) ? (a) : (b))
+
+//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,
+ OPTBIT_NO_EMPTY,
+ OPTBIT_UPTO_NUMBER,
+ OPTBIT_UPTO_SIZE,
+ OPTBIT_EOF_STRING,
+ OPTBIT_EOF_STRING1,
+ IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
+ IF_FEATURE_XARGS_SUPPORT_TERMOPT( OPTBIT_TERMINATE ,)
+ IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( OPTBIT_ZEROTERM ,)
+
+ OPT_VERBOSE = 1 << OPTBIT_VERBOSE ,
+ OPT_NO_EMPTY = 1 << OPTBIT_NO_EMPTY ,
+ OPT_UPTO_NUMBER = 1 << OPTBIT_UPTO_NUMBER,
+ OPT_UPTO_SIZE = 1 << OPTBIT_UPTO_SIZE ,
+ OPT_EOF_STRING = 1 << OPTBIT_EOF_STRING , /* GNU: -e[<param>] */
+ OPT_EOF_STRING1 = 1 << OPTBIT_EOF_STRING1, /* SUS: -E<param> */
+ 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,
+};
+#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")
+
+int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int xargs_main(int argc, char **argv)
+{
+ int i;
+ int child_error = 0;
+ char *max_args;
+ char *max_chars;
+ char *buf;
+ unsigned opt;
+ int n_max_chars;
+ int n_max_arg;
+#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
+ char* FAST_FUNC (*read_args)(int, int, char*) = process_stdin;
+#else
+#define read_args process_stdin
+#endif
+
+ INIT_G();
+
+#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?
+ * This is used for portability:
+ * old xargs was using "_" as default for -E / -e */
+ 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);
+
+ argv += optind;
+ argc -= optind;
+ if (!argv[0]) {
+ /* default behavior is to echo all the filenames */
+ *--argv = (char*)"echo";
+ argc++;
+ }
+
+ /* -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".
+ */
+ {
+ 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) {
+ 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;
+ }
+ /* Sanity check */
+ if (n_max_chars <= 0) {
+ bb_error_msg_and_die("can't fit single argument within argument list size limit");
+ }
-char outlin[MAX_ARGLINE];
-char inlin[MAX_ARGLINE];
-char startlin[MAX_ARGLINE];
-char *ending = NULL;
-char traceflag = 0;
+ 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];
+
+ while (1) {
+ char *rem;
+
+ G.idx = argc;
+ rem = read_args(n_max_chars, n_max_arg, buf);
+ store_param(NULL);
+
+ if (!G.args[argc]) {
+ if (*rem != '\0')
+ bb_error_msg_and_die("argument line too long");
+ if (opt & OPT_NO_EMPTY)
+ break;
+ }
+ opt |= OPT_NO_EMPTY;
+
+ if (opt & (OPT_INTERACTIVE | OPT_VERBOSE)) {
+ const char *fmt = " %s" + 1;
+ char **args = G.args;
+ for (i = 0; args[i]; i++) {
+ fprintf(stderr, fmt, args[i]);
+ fmt = " %s";
+ }
+ if (!(opt & OPT_INTERACTIVE))
+ bb_putchar_stderr('\n');
+ }
+
+ if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) {
+ child_error = xargs_exec();
+ }
+
+ if (child_error > 0 && child_error != 123) {
+ break;
+ }
+
+ overlapping_strcpy(buf, rem);
+ } /* while */
+
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ free(G.args);
+ free(buf);
+ }
+
+ return child_error;
+}
+
+
+#ifdef TEST
+
+const char *applet_name = "debug stuff usage";
+
+void bb_show_usage(void)
+{
+ fprintf(stderr, "Usage: %s [-p] [-r] [-t] -[x] [-n max_arg] [-s max_chars]\n",
+ applet_name);
+ exit(EXIT_FAILURE);
+}
-int xargs_main(int ac, char **av)
+int main(int argc, char **argv)
{
- int outlen, inlen, startlen, endlen=0, i;
- char errflg = 0;
- int maxlin = MAX_ARGLINE;
-
- while ((i = getopt(ac, av, "tl:e:")) != EOF)
- switch (i) {
- case 't': traceflag = 1; break;
- case 'l': maxlin = min(MAX_ARGLINE, atoi(optarg)); break;
- case 'e': ending = optarg; break;
- case '?': errflg++; break;
- }
- if (errflg) {
- fprintf(stderr, USAGE);
- exit(2);
- }
-
- startlin[0] = 0;
- if (optind == ac) {
- strcat(startlin, "echo ");
- }
- else for ( ; optind < ac; optind++) {
- strcat(startlin, av[optind]);
- strcat(startlin, " ");
- }
- startlen = strlen(startlin);
- if (ending) endlen = strlen(ending);
- maxlin = maxlin - 1 - endlen; /* Pre-compute */
-
- strcpy(outlin, startlin);
- outlen = startlen;
-
- while (gets(inlin) != NULL) {
- inlen = strlen(inlin);
- if (maxlin <= (outlen + inlen)) {
- if (outlen == startlen) {
- fprintf(stderr, "%s: Line length too short to process '%s'\n",
- av[0], inlin);
- exit(3);
- }
- if (ending) strcat(outlin, ending);
- if (traceflag) fputs(outlin,stderr);
- errno = 0;
- if (0 != system(outlin)) {
- if (errno != 0) perror("xargs");
- exit(1);
- }
- strcpy(outlin, startlin);
- outlen = startlen;
- }
- strcat(outlin, inlin);
- strcat(outlin, " ");
- outlen = outlen + inlen + 1;
- }
- if (outlen != startlen) {
- if (ending) strcat(outlin, ending);
- if (traceflag) fputs(outlin,stderr);
- errno = 0;
- if (0 != system(outlin)) {
- if (errno != 0) perror("xargs");
- exit(1);
- }
- }
- return 0;
+ return xargs_main(argc, argv);
}
+#endif /* TEST */
projects / oweals / busybox.git / blobdiff