1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * John B. Roll Jr.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * $xMach: xargs.c,v 1.6 2002/02/23 05:27:47 tim Exp $
35 */
36
37 #include <sys/types.h>
38 #include <sys/wait.h>
39 #include <sys/time.h>
40 #include <sys/limits.h>
41 #include <sys/resource.h>
42 #include <err.h>
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <getopt.h>
46 #include <langinfo.h>
47 #include <locale.h>
48 #include <paths.h>
49 #include <regex.h>
50 #include <stdbool.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <unistd.h>
55
56 #include "pathnames.h"
57
58 static void parse_input(int, char *[]);
59 static void prerun(int, char *[]);
60 static int prompt(void);
61 static void run(char **);
62 static void usage(void);
63 bool strnsubst(char **, const char *, const char *, size_t);
64 static pid_t xwait(int block, int *status);
65 static void xexit(const char *, const int);
66 static void waitchildren(const char *, int);
67 static void pids_init(void);
68 static int pids_empty(void);
69 static int pids_full(void);
70 static void pids_add(pid_t pid);
71 static int pids_remove(pid_t pid);
72 static int findslot(pid_t pid);
73 static int findfreeslot(void);
74 static void clearslot(int slot);
75
76 static char echo[] = _PATH_ECHO;
77 static char **av, **bxp, **ep, **endxp, **xp;
78 static char *argp, *bbp, *ebp, *inpline, *p, *replstr;
79 static const char *eofstr;
80 static long eoflen;
81 static int count, insingle, indouble, oflag, pflag, tflag, Rflag, rval, zflag;
82 static int cnt, Iflag, jfound, Lflag, Sflag, wasquoted, xflag;
83 static int curprocs, maxprocs;
84 static pid_t *childpids;
85
86 static volatile int childerr;
87
88 extern char **environ;
89
90 static const char *optstr = "+0E:I:J:L:n:oP:pR:S:s:rtx";
91
92 static const struct option long_options[] =
93 {
94 {"exit", no_argument, NULL, 'x'},
95 {"interactive", no_argument, NULL, 'p'},
96 {"max-args", required_argument, NULL, 'n'},
97 {"max-chars", required_argument, NULL, 's'},
98 {"max-procs", required_argument, NULL, 'P'},
99 {"no-run-if-empty", no_argument, NULL, 'r'},
100 {"null", no_argument, NULL, '0'},
101 {"verbose", no_argument, NULL, 't'},
102
103 {NULL, no_argument, NULL, 0},
104 };
105
106 int
main(int argc,char * argv[])107 main(int argc, char *argv[])
108 {
109 long arg_max;
110 int ch, Jflag, nargs, nflag, nline;
111 size_t linelen;
112 struct rlimit rl;
113 const char *errstr;
114
115 inpline = replstr = NULL;
116 ep = environ;
117 eofstr = "";
118 eoflen = 0;
119 Jflag = nflag = 0;
120
121 (void)setlocale(LC_ALL, "");
122
123 /*
124 * POSIX.2 limits the exec line length to ARG_MAX - 2K. Running that
125 * caused some E2BIG errors, so it was changed to ARG_MAX - 4K. Given
126 * that the smallest argument is 2 bytes in length, this means that
127 * the number of arguments is limited to:
128 *
129 * (ARG_MAX - 4K - LENGTH(utility + arguments)) / 2.
130 *
131 * We arbitrarily limit the number of arguments to 5000. This is
132 * allowed by POSIX.2 as long as the resulting minimum exec line is
133 * at least LINE_MAX. Realloc'ing as necessary is possible, but
134 * probably not worthwhile.
135 */
136 nargs = 5000;
137 if ((arg_max = sysconf(_SC_ARG_MAX)) == -1)
138 errx(1, "sysconf(_SC_ARG_MAX) failed");
139 nline = arg_max - 4 * 1024;
140 while (*ep != NULL) {
141 /* 1 byte for each '\0' */
142 nline -= strlen(*ep++) + 1 + sizeof(*ep);
143 }
144 maxprocs = 1;
145 while ((ch = getopt_long(argc, argv, optstr, long_options, NULL)) != -1)
146 switch (ch) {
147 case 'E':
148 eofstr = optarg;
149 eoflen = strlen(eofstr);
150 break;
151 case 'I':
152 Jflag = 0;
153 Iflag = 1;
154 Lflag = 1;
155 replstr = optarg;
156 break;
157 case 'J':
158 Iflag = 0;
159 Jflag = 1;
160 replstr = optarg;
161 break;
162 case 'L':
163 Lflag = (int)strtonum(optarg, 1, INT_MAX, &errstr);
164 if (errstr)
165 errx(1, "-%c %s: %s", ch, optarg, errstr);
166 break;
167 case 'n':
168 nflag = 1;
169 nargs = (int)strtonum(optarg, 1, INT_MAX, &errstr);
170 if (errstr)
171 errx(1, "-%c %s: %s", ch, optarg, errstr);
172 break;
173 case 'o':
174 oflag = 1;
175 break;
176 case 'P':
177 maxprocs = (int)strtonum(optarg, 0, INT_MAX, &errstr);
178 if (errstr)
179 errx(1, "-%c %s: %s", ch, optarg, errstr);
180 if (getrlimit(RLIMIT_NPROC, &rl) != 0)
181 errx(1, "getrlimit failed");
182 if (maxprocs == 0 || maxprocs > rl.rlim_cur)
183 maxprocs = rl.rlim_cur;
184 break;
185 case 'p':
186 pflag = 1;
187 break;
188 case 'R':
189 Rflag = (int)strtonum(optarg, INT_MIN, INT_MAX, &errstr);
190 if (errstr)
191 errx(1, "-%c %s: %s", ch, optarg, errstr);
192 if (!Rflag)
193 errx(1, "-%c %s: %s", ch, optarg, "must be non-zero");
194 break;
195 case 'r':
196 /* GNU compatibility */
197 break;
198 case 'S':
199 Sflag = (int)strtonum(optarg, 0, INT_MAX, &errstr);
200 if (errstr)
201 errx(1, "-%c %s: %s", ch, optarg, errstr);
202 break;
203 case 's':
204 nline = (int)strtonum(optarg, 0, INT_MAX, &errstr);
205 if (errstr)
206 errx(1, "-%c %s: %s", ch, optarg, errstr);
207 break;
208 case 't':
209 tflag = 1;
210 break;
211 case 'x':
212 xflag = 1;
213 break;
214 case '0':
215 zflag = 1;
216 break;
217 case '?':
218 default:
219 usage();
220 }
221 argc -= optind;
222 argv += optind;
223
224 if (!Iflag && Rflag)
225 usage();
226 if (!Iflag && Sflag)
227 usage();
228 if (Iflag && !Rflag)
229 Rflag = 5;
230 if (Iflag && !Sflag)
231 Sflag = 255;
232 if (xflag && !nflag)
233 usage();
234 if (Iflag || Lflag)
235 xflag = 1;
236 if (replstr != NULL && *replstr == '\0')
237 errx(1, "replstr may not be empty");
238
239 pids_init();
240
241 /*
242 * Allocate pointers for the utility name, the utility arguments,
243 * the maximum arguments to be read from stdin and the trailing
244 * NULL.
245 */
246 linelen = 1 + argc + (size_t)nargs + 1;
247 if ((av = bxp = malloc(linelen * sizeof(char *))) == NULL)
248 errx(1, "malloc failed");
249
250 /*
251 * Use the user's name for the utility as argv[0], just like the
252 * shell. Echo is the default. Set up pointers for the user's
253 * arguments.
254 */
255 if (*argv == NULL)
256 cnt = strlen(*bxp++ = echo);
257 else {
258 do {
259 if (Jflag && strcmp(*argv, replstr) == 0) {
260 char **avj;
261 jfound = 1;
262 argv++;
263 for (avj = argv; *avj; avj++)
264 cnt += strlen(*avj) + 1;
265 break;
266 }
267 cnt += strlen(*bxp++ = *argv) + 1;
268 } while (*++argv != NULL);
269 }
270
271 /*
272 * Set up begin/end/traversing pointers into the array. The -n
273 * count doesn't include the trailing NULL pointer, so the malloc
274 * added in an extra slot.
275 */
276 endxp = (xp = bxp) + nargs;
277
278 /*
279 * Allocate buffer space for the arguments read from stdin and the
280 * trailing NULL. Buffer space is defined as the default or specified
281 * space, minus the length of the utility name and arguments. Set up
282 * begin/end/traversing pointers into the array. The -s count does
283 * include the trailing NULL, so the malloc didn't add in an extra
284 * slot.
285 */
286 nline -= cnt;
287 if (nline <= 0)
288 errx(1, "insufficient space for command");
289
290 if ((bbp = malloc((size_t)(nline + 1))) == NULL)
291 errx(1, "malloc failed");
292 ebp = (argp = p = bbp) + nline - 1;
293 for (;;)
294 parse_input(argc, argv);
295 }
296
297 static void
parse_input(int argc,char * argv[])298 parse_input(int argc, char *argv[])
299 {
300 int ch, foundeof;
301 char **avj;
302
303 foundeof = 0;
304
305 switch (ch = getchar()) {
306 case EOF:
307 /* No arguments since last exec. */
308 if (p == bbp) {
309 waitchildren(*av, 1);
310 exit(rval);
311 }
312 goto arg1;
313 case ' ':
314 case '\t':
315 /* Quotes escape tabs and spaces. */
316 if (insingle || indouble || zflag)
317 goto addch;
318 goto arg2;
319 case '\0':
320 if (zflag) {
321 /*
322 * Increment 'count', so that nulls will be treated
323 * as end-of-line, as well as end-of-argument. This
324 * is needed so -0 works properly with -I and -L.
325 */
326 count++;
327 goto arg2;
328 }
329 goto addch;
330 case '\n':
331 if (zflag)
332 goto addch;
333 count++; /* Indicate end-of-line (used by -L) */
334
335 /* Quotes do not escape newlines. */
336 arg1: if (insingle || indouble) {
337 warnx("unterminated quote");
338 xexit(*av, 1);
339 }
340 arg2:
341 foundeof = eoflen != 0 && p - argp == eoflen &&
342 strncmp(argp, eofstr, eoflen) == 0;
343
344 /* Do not make empty args unless they are quoted */
345 if ((argp != p || wasquoted) && !foundeof) {
346 *p++ = '\0';
347 *xp++ = argp;
348 if (Iflag) {
349 size_t curlen;
350
351 if (inpline == NULL)
352 curlen = 0;
353 else {
354 /*
355 * If this string is not zero
356 * length, append a space for
357 * separation before the next
358 * argument.
359 */
360 if ((curlen = strlen(inpline)))
361 strcat(inpline, " ");
362 }
363 curlen++;
364 /*
365 * Allocate enough to hold what we will
366 * be holding in a second, and to append
367 * a space next time through, if we have
368 * to.
369 */
370 inpline = realloc(inpline, curlen + 2 +
371 strlen(argp));
372 if (inpline == NULL) {
373 warnx("realloc failed");
374 xexit(*av, 1);
375 }
376 if (curlen == 1)
377 strcpy(inpline, argp);
378 else
379 strcat(inpline, argp);
380 }
381 }
382
383 /*
384 * If max'd out on args or buffer, or reached EOF,
385 * run the command. If xflag and max'd out on buffer
386 * but not on args, object. Having reached the limit
387 * of input lines, as specified by -L is the same as
388 * maxing out on arguments.
389 */
390 if (xp == endxp || p > ebp || ch == EOF ||
391 (Lflag <= count && xflag) || foundeof) {
392 if (xflag && xp != endxp && p > ebp) {
393 warnx("insufficient space for arguments");
394 xexit(*av, 1);
395 }
396 if (jfound) {
397 for (avj = argv; *avj; avj++)
398 *xp++ = *avj;
399 }
400 prerun(argc, av);
401 if (ch == EOF || foundeof) {
402 waitchildren(*av, 1);
403 exit(rval);
404 }
405 p = bbp;
406 xp = bxp;
407 count = 0;
408 }
409 argp = p;
410 wasquoted = 0;
411 break;
412 case '\'':
413 if (indouble || zflag)
414 goto addch;
415 insingle = !insingle;
416 wasquoted = 1;
417 break;
418 case '"':
419 if (insingle || zflag)
420 goto addch;
421 indouble = !indouble;
422 wasquoted = 1;
423 break;
424 case '\\':
425 if (zflag)
426 goto addch;
427 /* Backslash escapes anything, is escaped by quotes. */
428 if (!insingle && !indouble && (ch = getchar()) == EOF) {
429 warnx("backslash at EOF");
430 xexit(*av, 1);
431 }
432 /* FALLTHROUGH */
433 default:
434 addch: if (p < ebp) {
435 *p++ = ch;
436 break;
437 }
438
439 /* If only one argument, not enough buffer space. */
440 if (bxp == xp) {
441 warnx("insufficient space for argument");
442 xexit(*av, 1);
443 }
444 /* Didn't hit argument limit, so if xflag object. */
445 if (xflag) {
446 warnx("insufficient space for arguments");
447 xexit(*av, 1);
448 }
449
450 if (jfound) {
451 for (avj = argv; *avj; avj++)
452 *xp++ = *avj;
453 }
454 prerun(argc, av);
455 xp = bxp;
456 cnt = ebp - argp;
457 memcpy(bbp, argp, (size_t)cnt);
458 p = (argp = bbp) + cnt;
459 *p++ = ch;
460 break;
461 }
462 }
463
464 /*
465 * Do things necessary before run()'ing, such as -I substitution,
466 * and then call run().
467 */
468 static void
prerun(int argc,char * argv[])469 prerun(int argc, char *argv[])
470 {
471 char **tmp, **tmp2, **avj;
472 int repls;
473
474 repls = Rflag;
475
476 if (argc == 0 || repls == 0) {
477 *xp = NULL;
478 run(argv);
479 return;
480 }
481
482 avj = argv;
483
484 /*
485 * Allocate memory to hold the argument list, and
486 * a NULL at the tail.
487 */
488 tmp = malloc((argc + 1) * sizeof(char *));
489 if (tmp == NULL) {
490 warnx("malloc failed");
491 xexit(*argv, 1);
492 }
493 tmp2 = tmp;
494
495 /*
496 * Save the first argument and iterate over it, we
497 * cannot do strnsubst() to it.
498 */
499 if ((*tmp++ = strdup(*avj++)) == NULL) {
500 warnx("strdup failed");
501 xexit(*argv, 1);
502 }
503
504 /*
505 * For each argument to utility, if we have not used up
506 * the number of replacements we are allowed to do, and
507 * if the argument contains at least one occurrence of
508 * replstr, call strnsubst(), else just save the string.
509 * Iterations over elements of avj and tmp are done
510 * where appropriate.
511 */
512 while (--argc) {
513 *tmp = *avj++;
514 if (repls && strstr(*tmp, replstr) != NULL) {
515 if (strnsubst(tmp++, replstr, inpline, (size_t)Sflag)) {
516 warnx("command line cannot be assembled, too long");
517 xexit(*argv, 1);
518 }
519 if (repls > 0)
520 repls--;
521 } else {
522 if ((*tmp = strdup(*tmp)) == NULL) {
523 warnx("strdup failed");
524 xexit(*argv, 1);
525 }
526 tmp++;
527 }
528 }
529
530 /*
531 * Run it.
532 */
533 *tmp = NULL;
534 run(tmp2);
535
536 /*
537 * Walk from the tail to the head, free along the way.
538 */
539 for (; tmp2 != tmp; tmp--)
540 free(*tmp);
541 /*
542 * Now free the list itself.
543 */
544 free(tmp2);
545
546 /*
547 * Free the input line buffer, if we have one.
548 */
549 if (inpline != NULL) {
550 free(inpline);
551 inpline = NULL;
552 }
553 }
554
555 static void
run(char ** argv)556 run(char **argv)
557 {
558 pid_t pid;
559 int fd;
560 char **avec;
561
562 /*
563 * If the user wants to be notified of each command before it is
564 * executed, notify them. If they want the notification to be
565 * followed by a prompt, then prompt them.
566 */
567 if (tflag || pflag) {
568 (void)fprintf(stderr, "%s", *argv);
569 for (avec = argv + 1; *avec != NULL; ++avec)
570 (void)fprintf(stderr, " %s", *avec);
571 /*
572 * If the user has asked to be prompted, do so.
573 */
574 if (pflag)
575 /*
576 * If they asked not to exec, return without execution
577 * but if they asked to, go to the execution. If we
578 * could not open their tty, break the switch and drop
579 * back to -t behaviour.
580 */
581 switch (prompt()) {
582 case 0:
583 return;
584 case 1:
585 goto exec;
586 case 2:
587 break;
588 }
589 (void)fprintf(stderr, "\n");
590 (void)fflush(stderr);
591 }
592 exec:
593 childerr = 0;
594 switch (pid = vfork()) {
595 case -1:
596 warn("vfork");
597 xexit(*argv, 1);
598 case 0:
599 if (oflag) {
600 if ((fd = open(_PATH_TTY, O_RDONLY)) == -1)
601 err(1, "can't open /dev/tty");
602 } else {
603 fd = open(_PATH_DEVNULL, O_RDONLY);
604 }
605 if (fd > STDIN_FILENO) {
606 if (dup2(fd, STDIN_FILENO) != 0)
607 err(1, "can't dup2 to stdin");
608 close(fd);
609 }
610 execvp(argv[0], argv);
611 childerr = errno;
612 _exit(1);
613 }
614 pids_add(pid);
615 waitchildren(*argv, 0);
616 }
617
618 /*
619 * Wait for a tracked child to exit and return its pid and exit status.
620 *
621 * Ignores (discards) all untracked child processes.
622 * Returns -1 and sets errno to ECHILD if no tracked children exist.
623 * If block is set, waits indefinitely for a child process to exit.
624 * If block is not set and no children have exited, returns 0 immediately.
625 */
626 static pid_t
xwait(int block,int * status)627 xwait(int block, int *status) {
628 pid_t pid;
629
630 if (pids_empty()) {
631 errno = ECHILD;
632 return (-1);
633 }
634
635 while ((pid = waitpid(-1, status, block ? 0 : WNOHANG)) > 0)
636 if (pids_remove(pid))
637 break;
638
639 return (pid);
640 }
641
642 static void
xexit(const char * name,const int exit_code)643 xexit(const char *name, const int exit_code) {
644 waitchildren(name, 1);
645 exit(exit_code);
646 }
647
648 static void
waitchildren(const char * name,int waitall)649 waitchildren(const char *name, int waitall)
650 {
651 pid_t pid;
652 int status;
653 int cause_exit = 0;
654
655 while ((pid = xwait(waitall || pids_full(), &status)) > 0) {
656 /*
657 * If we couldn't invoke the utility or if utility exited
658 * because of a signal or with a value of 255, warn (per
659 * POSIX), and then wait until all other children have
660 * exited before exiting 1-125. POSIX requires us to stop
661 * reading if child exits because of a signal or with 255,
662 * but it does not require us to exit immediately; waiting
663 * is preferable to orphaning.
664 */
665 if (childerr != 0 && cause_exit == 0) {
666 errno = childerr;
667 waitall = 1;
668 cause_exit = errno == ENOENT ? 127 : 126;
669 warn("%s", name);
670 } else if (WIFSIGNALED(status)) {
671 waitall = cause_exit = 1;
672 warnx("%s: terminated with signal %d; aborting",
673 name, WTERMSIG(status));
674 } else if (WEXITSTATUS(status) == 255) {
675 waitall = cause_exit = 1;
676 warnx("%s: exited with status 255; aborting", name);
677 } else if (WEXITSTATUS(status))
678 rval = 1;
679 }
680
681 if (cause_exit)
682 exit(cause_exit);
683 if (pid == -1 && errno != ECHILD)
684 err(1, "waitpid");
685 }
686
687 #define NOPID (0)
688
689 static void
pids_init(void)690 pids_init(void)
691 {
692 int i;
693
694 if ((childpids = malloc(maxprocs * sizeof(*childpids))) == NULL)
695 errx(1, "malloc failed");
696
697 for (i = 0; i < maxprocs; i++)
698 clearslot(i);
699 }
700
701 static int
pids_empty(void)702 pids_empty(void)
703 {
704
705 return (curprocs == 0);
706 }
707
708 static int
pids_full(void)709 pids_full(void)
710 {
711
712 return (curprocs >= maxprocs);
713 }
714
715 static void
pids_add(pid_t pid)716 pids_add(pid_t pid)
717 {
718 int slot;
719
720 slot = findfreeslot();
721 childpids[slot] = pid;
722 curprocs++;
723 }
724
725 static int
pids_remove(pid_t pid)726 pids_remove(pid_t pid)
727 {
728 int slot;
729
730 if ((slot = findslot(pid)) < 0)
731 return (0);
732
733 clearslot(slot);
734 curprocs--;
735 return (1);
736 }
737
738 static int
findfreeslot(void)739 findfreeslot(void)
740 {
741 int slot;
742
743 if ((slot = findslot(NOPID)) < 0)
744 errx(1, "internal error: no free pid slot");
745 return (slot);
746 }
747
748 static int
findslot(pid_t pid)749 findslot(pid_t pid)
750 {
751 int slot;
752
753 for (slot = 0; slot < maxprocs; slot++)
754 if (childpids[slot] == pid)
755 return (slot);
756 return (-1);
757 }
758
759 static void
clearslot(int slot)760 clearslot(int slot)
761 {
762
763 childpids[slot] = NOPID;
764 }
765
766 /*
767 * Prompt the user about running a command.
768 */
769 static int
prompt(void)770 prompt(void)
771 {
772 regex_t cre;
773 size_t rsize = 0;
774 int match;
775 char *response = NULL;
776 FILE *ttyfp;
777
778 if ((ttyfp = fopen(_PATH_TTY, "r")) == NULL)
779 return (2); /* Indicate that the TTY failed to open. */
780 (void)fprintf(stderr, "?...");
781 (void)fflush(stderr);
782 if (getline(&response, &rsize, ttyfp) < 0 ||
783 regcomp(&cre, nl_langinfo(YESEXPR), REG_EXTENDED) != 0) {
784 (void)fclose(ttyfp);
785 return (0);
786 }
787 match = regexec(&cre, response, 0, NULL, 0);
788 free(response);
789 (void)fclose(ttyfp);
790 regfree(&cre);
791 return (match == 0);
792 }
793
794 static void
usage(void)795 usage(void)
796 {
797
798 fprintf(stderr,
799 "usage: xargs [-0opt] [-E eofstr] [-I replstr [-R replacements] [-S replsize]]\n"
800 " [-J replstr] [-L number] [-n number [-x]] [-P maxprocs]\n"
801 " [-s size] [utility [argument ...]]\n");
802 exit(1);
803 }
804