2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * $xMach: xargs.c,v 1.6 2002/02/23 05:27:47 tim Exp $
41 static const char copyright[] =
42 "@(#) Copyright (c) 1990, 1993\n\
43 The Regents of the University of California. All rights reserved.\n";
47 static char sccsid[] = "@(#)xargs.c 8.1 (Berkeley) 6/6/93";
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD$");
53 #include <sys/param.h>
68 #include "pathnames.h"
70 static void parse_input(int, char *[]);
71 static void prerun(int, char *[]);
72 static int prompt(void);
73 static void run(char **);
74 static void usage(void);
75 void strnsubst(char **, const char *, const char *, size_t);
76 static void waitchildren(const char *, int);
78 static char echo[] = _PATH_ECHO;
79 static char **av, **bxp, **ep, **endxp, **xp;
80 static char *argp, *bbp, *ebp, *inpline, *p, *replstr;
81 static const char *eofstr;
82 static int count, insingle, indouble, oflag, pflag, tflag, Rflag, rval, zflag;
83 static int cnt, Iflag, jfound, Lflag, Sflag, wasquoted, xflag;
84 static int curprocs, maxprocs;
86 static volatile int childerr;
88 extern char **environ;
91 main(int argc, char *argv[])
94 int ch, Jflag, nargs, nflag, nline;
98 inpline = replstr = NULL;
103 (void)setlocale(LC_ALL, "");
106 * POSIX.2 limits the exec line length to ARG_MAX - 2K. Running that
107 * caused some E2BIG errors, so it was changed to ARG_MAX - 4K. Given
108 * that the smallest argument is 2 bytes in length, this means that
109 * the number of arguments is limited to:
111 * (ARG_MAX - 4K - LENGTH(utility + arguments)) / 2.
113 * We arbitrarily limit the number of arguments to 5000. This is
114 * allowed by POSIX.2 as long as the resulting minimum exec line is
115 * at least LINE_MAX. Realloc'ing as necessary is possible, but
116 * probably not worthwhile.
119 if ((arg_max = sysconf(_SC_ARG_MAX)) == -1)
120 errx(1, "sysconf(_SC_ARG_MAX) failed");
121 nline = arg_max - 4 * 1024;
122 while (*ep != NULL) {
123 /* 1 byte for each '\0' */
124 nline -= strlen(*ep++) + 1 + sizeof(*ep);
127 while ((ch = getopt(argc, argv, "0E:I:J:L:n:oP:pR:S:s:rtx")) != -1)
144 Lflag = atoi(optarg);
148 if ((nargs = atoi(optarg)) <= 0)
149 errx(1, "illegal argument count");
155 if ((maxprocs = atoi(optarg)) <= 0)
156 errx(1, "max. processes must be >0");
162 Rflag = strtol(optarg, &endptr, 10);
164 errx(1, "replacements must be a number");
167 /* GNU compatibility */
170 Sflag = strtoul(optarg, &endptr, 10);
172 errx(1, "replsize must be a number");
175 nline = atoi(optarg);
205 if (replstr != NULL && *replstr == '\0')
206 errx(1, "replstr may not be empty");
209 * Allocate pointers for the utility name, the utility arguments,
210 * the maximum arguments to be read from stdin and the trailing
213 linelen = 1 + argc + nargs + 1;
214 if ((av = bxp = malloc(linelen * sizeof(char **))) == NULL)
215 errx(1, "malloc failed");
218 * Use the user's name for the utility as argv[0], just like the
219 * shell. Echo is the default. Set up pointers for the user's
223 cnt = strlen(*bxp++ = echo);
226 if (Jflag && strcmp(*argv, replstr) == 0) {
230 for (avj = argv; *avj; avj++)
231 cnt += strlen(*avj) + 1;
234 cnt += strlen(*bxp++ = *argv) + 1;
235 } while (*++argv != NULL);
239 * Set up begin/end/traversing pointers into the array. The -n
240 * count doesn't include the trailing NULL pointer, so the malloc
241 * added in an extra slot.
243 endxp = (xp = bxp) + nargs;
246 * Allocate buffer space for the arguments read from stdin and the
247 * trailing NULL. Buffer space is defined as the default or specified
248 * space, minus the length of the utility name and arguments. Set up
249 * begin/end/traversing pointers into the array. The -s count does
250 * include the trailing NULL, so the malloc didn't add in an extra
255 errx(1, "insufficient space for command");
257 if ((bbp = malloc((size_t)(nline + 1))) == NULL)
258 errx(1, "malloc failed");
259 ebp = (argp = p = bbp) + nline - 1;
261 parse_input(argc, argv);
265 parse_input(int argc, char *argv[])
272 switch (ch = getchar()) {
274 /* No arguments since last exec. */
276 waitchildren(*argv, 1);
282 /* Quotes escape tabs and spaces. */
283 if (insingle || indouble || zflag)
289 * Increment 'count', so that nulls will be treated
290 * as end-of-line, as well as end-of-argument. This
291 * is needed so -0 works properly with -I and -L.
300 count++; /* Indicate end-of-line (used by -L) */
302 /* Quotes do not escape newlines. */
303 arg1: if (insingle || indouble)
304 errx(1, "unterminated quote");
306 foundeof = *eofstr != '\0' &&
307 strncmp(argp, eofstr, p - argp) == 0;
309 /* Do not make empty args unless they are quoted */
310 if ((argp != p || wasquoted) && !foundeof) {
320 * If this string is not zero
321 * length, append a space for
322 * separation before the next
325 if ((curlen = strlen(inpline)))
326 strcat(inpline, " ");
330 * Allocate enough to hold what we will
331 * be holding in a second, and to append
332 * a space next time through, if we have
335 inpline = realloc(inpline, curlen + 2 +
338 errx(1, "realloc failed");
340 strcpy(inpline, argp);
342 strcat(inpline, argp);
347 * If max'd out on args or buffer, or reached EOF,
348 * run the command. If xflag and max'd out on buffer
349 * but not on args, object. Having reached the limit
350 * of input lines, as specified by -L is the same as
351 * maxing out on arguments.
353 if (xp == endxp || p > ebp || ch == EOF ||
354 (Lflag <= count && xflag) || foundeof) {
355 if (xflag && xp != endxp && p > ebp)
356 errx(1, "insufficient space for arguments");
358 for (avj = argv; *avj; avj++)
362 if (ch == EOF || foundeof) {
363 waitchildren(*argv, 1);
374 if (indouble || zflag)
376 insingle = !insingle;
380 if (insingle || zflag)
382 indouble = !indouble;
388 /* Backslash escapes anything, is escaped by quotes. */
389 if (!insingle && !indouble && (ch = getchar()) == EOF)
390 errx(1, "backslash at EOF");
393 addch: if (p < ebp) {
398 /* If only one argument, not enough buffer space. */
400 errx(1, "insufficient space for argument");
401 /* Didn't hit argument limit, so if xflag object. */
403 errx(1, "insufficient space for arguments");
406 for (avj = argv; *avj; avj++)
412 memcpy(bbp, argp, (size_t)cnt);
413 p = (argp = bbp) + cnt;
420 * Do things necessary before run()'ing, such as -I substitution,
421 * and then call run().
424 prerun(int argc, char *argv[])
426 char **tmp, **tmp2, **avj;
431 if (argc == 0 || repls == 0) {
440 * Allocate memory to hold the argument list, and
441 * a NULL at the tail.
443 tmp = malloc((argc + 1) * sizeof(char**));
445 errx(1, "malloc failed");
449 * Save the first argument and iterate over it, we
450 * cannot do strnsubst() to it.
452 if ((*tmp++ = strdup(*avj++)) == NULL)
453 errx(1, "strdup failed");
456 * For each argument to utility, if we have not used up
457 * the number of replacements we are allowed to do, and
458 * if the argument contains at least one occurrence of
459 * replstr, call strnsubst(), else just save the string.
460 * Iterations over elements of avj and tmp are done
465 if (repls && strstr(*tmp, replstr) != NULL) {
466 strnsubst(tmp++, replstr, inpline, (size_t)Sflag);
470 if ((*tmp = strdup(*tmp)) == NULL)
471 errx(1, "strdup failed");
483 * Walk from the tail to the head, free along the way.
485 for (; tmp2 != tmp; tmp--)
488 * Now free the list itself.
493 * Free the input line buffer, if we have one.
495 if (inpline != NULL) {
509 * If the user wants to be notified of each command before it is
510 * executed, notify them. If they want the notification to be
511 * followed by a prompt, then prompt them.
513 if (tflag || pflag) {
514 (void)fprintf(stderr, "%s", *argv);
515 for (avec = argv + 1; *avec != NULL; ++avec)
516 (void)fprintf(stderr, " %s", *avec);
518 * If the user has asked to be prompted, do so.
522 * If they asked not to exec, return without execution
523 * but if they asked to, go to the execution. If we
524 * could not open their tty, break the switch and drop
525 * back to -t behaviour.
535 (void)fprintf(stderr, "\n");
536 (void)fflush(stderr);
540 switch (pid = vfork()) {
545 if ((fd = open(_PATH_TTY, O_RDONLY)) == -1)
546 err(1, "can't open /dev/tty");
548 fd = open(_PATH_DEVNULL, O_RDONLY);
550 if (fd > STDIN_FILENO) {
551 if (dup2(fd, STDIN_FILENO) != 0)
552 err(1, "can't dup2 to stdin");
555 execvp(argv[0], argv);
560 waitchildren(*argv, 0);
564 waitchildren(const char *name, int waitall)
569 while ((pid = waitpid(-1, &status, !waitall && curprocs < maxprocs ?
572 /* If we couldn't invoke the utility, exit. */
575 err(errno == ENOENT ? 127 : 126, "%s", name);
578 * If utility signaled or exited with a value of 255,
581 if (WIFSIGNALED(status) || WEXITSTATUS(status) == 255)
583 if (WEXITSTATUS(status))
586 if (pid == -1 && errno != ECHILD)
591 * Prompt the user about running a command.
602 if ((ttyfp = fopen(_PATH_TTY, "r")) == NULL)
603 return (2); /* Indicate that the TTY failed to open. */
604 (void)fprintf(stderr, "?...");
605 (void)fflush(stderr);
606 if ((response = fgetln(ttyfp, &rsize)) == NULL ||
607 regcomp(&cre, nl_langinfo(YESEXPR), REG_BASIC) != 0) {
611 response[rsize - 1] = '\0';
612 match = regexec(&cre, response, 0, NULL, 0);
622 "usage: xargs [-0opt] [-E eofstr] [-I replstr [-R replacements] [-S replsize]]\n"
623 " [-J replstr] [-L number] [-n number [-x]] [-P maxprocs]\n"
624 " [-s size] [utility [argument ...]]\n");