1 /*- 2 * Copyright (c) 1990, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * John B. Roll Jr. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 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. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * $xMach: xargs.c,v 1.6 2002/02/23 05:27:47 tim Exp $ 33 * 34 * @(#) Copyright (c) 1990, 1993 The Regents of the University of California. All rights reserved. 35 * @(#)xargs.c 8.1 (Berkeley) 6/6/93 36 * $FreeBSD: src/usr.bin/xargs/xargs.c,v 1.9.2.6 2003/06/01 21:40:35 mux Exp $ 37 */ 38 39 #include <sys/types.h> 40 #include <sys/wait.h> 41 42 #include <err.h> 43 #include <errno.h> 44 #include <fcntl.h> 45 #include <langinfo.h> 46 #include <limits.h> 47 #include <locale.h> 48 #include <paths.h> 49 #include <regex.h> 50 #include <stdint.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 #ifndef BOOTSTRAPPING 61 static int prompt(void); 62 #endif 63 static void run(char **); 64 static void usage(void); 65 void strnsubst(char **, const char *, const char *, size_t); 66 static void waitchildren(const char *, int); 67 68 static char echo[] = _PATH_ECHO; 69 static char **av, **bxp, **ep, **expx, **xp; 70 static char *argp, *bbp, *ebp, *inpline, *p, *replstr; 71 static const char *eofstr; 72 static int count, insingle, indouble, oflag, pflag, tflag, Rflag, rval, zflag; 73 static int cnt, Iflag, jfound, Lflag, wasquoted, xflag; 74 static int curprocs, maxprocs; 75 static volatile int childerr; 76 77 extern char **environ; 78 79 int 80 main(int argc, char *argv[]) 81 { 82 char *tmp; 83 long arg_max; 84 int ch, Jflag, nargs, nflag, nline; 85 size_t linelen; 86 87 inpline = replstr = NULL; 88 ep = environ; 89 eofstr = ""; 90 Jflag = nflag = 0; 91 92 (void)setlocale(LC_MESSAGES, ""); 93 94 /* 95 * POSIX.2 limits the exec line length to ARG_MAX - 2K. Running that 96 * caused some E2BIG errors, so it was changed to ARG_MAX - 4K. Given 97 * that the smallest argument is 2 bytes in length, this means that 98 * the number of arguments is limited to: 99 * 100 * (ARG_MAX - 4K - LENGTH(utility + arguments)) / 2. 101 * 102 * We arbitrarily limit the number of arguments to 5000. This is 103 * allowed by POSIX.2 as long as the resulting minimum exec line is 104 * at least LINE_MAX. Realloc'ing as necessary is possible, but 105 * probably not worthwhile. 106 */ 107 nargs = 5000; 108 if ((arg_max = sysconf(_SC_ARG_MAX)) == -1) 109 errx(1, "sysconf(_SC_ARG_MAX) failed"); 110 if (arg_max > INT32_MAX) { 111 /* cap arg_max to int32_t */ 112 arg_max = INT32_MAX; 113 } 114 nline = arg_max - 4 * 1024; 115 while (*ep != NULL) { 116 /* 1 byte for each '\0' */ 117 nline -= strlen(*ep++) + 1 + sizeof(*ep); 118 } 119 120 maxprocs = 1; 121 while ((ch = getopt(argc, argv, "0E:I:J:L:n:oprP:R:s:tx")) != -1) 122 switch(ch) { 123 case 'E': 124 eofstr = optarg; 125 break; 126 case 'I': 127 Jflag = 0; 128 Iflag = 1; 129 Lflag = 1; 130 replstr = optarg; 131 break; 132 case 'J': 133 Iflag = 0; 134 Jflag = 1; 135 replstr = optarg; 136 break; 137 case 'L': 138 Lflag = strtol(optarg, &tmp, 10); 139 if (*tmp != 0 || *optarg == 0) 140 errx(1, "illegal argument count"); 141 break; 142 case 'n': 143 nflag = 1; 144 if ((nargs = atoi(optarg)) <= 0) 145 errx(1, "illegal argument count"); 146 break; 147 case 'o': 148 oflag = 1; 149 break; 150 case 'p': 151 #ifndef BOOTSTRAPPING 152 pflag = 1; 153 #endif 154 break; 155 case 'P': 156 if ((maxprocs = atoi(optarg)) <= 0) 157 errx(1, "max.processes must be >0"); 158 break; 159 case 'R': 160 if ((Rflag = atoi(optarg)) <= 0) 161 errx(1, "illegal number of replacements"); 162 break; 163 case 'r': 164 /* GNU compatibility */ 165 /* --no-run-if-empty (this is our default) */ 166 break; 167 case 's': 168 nline = atoi(optarg); 169 break; 170 case 't': 171 tflag = 1; 172 break; 173 case 'x': 174 xflag = 1; 175 break; 176 case '0': 177 zflag = 1; 178 break; 179 case '?': 180 default: 181 usage(); 182 } 183 argc -= optind; 184 argv += optind; 185 186 if (!Iflag && Rflag) 187 usage(); 188 if (Iflag && !Rflag) 189 Rflag = 5; 190 if (xflag && !nflag) 191 usage(); 192 if (Iflag || Lflag) 193 xflag = 1; 194 if (replstr != NULL && *replstr == '\0') 195 errx(1, "replstr may not be empty"); 196 197 /* 198 * Allocate pointers for the utility name, the utility arguments, 199 * the maximum arguments to be read from stdin and the trailing 200 * NULL. 201 */ 202 linelen = 1 + argc + nargs + 1; 203 if ((av = bxp = malloc(linelen * sizeof(char **))) == NULL) 204 errx(1, "malloc failed"); 205 206 /* 207 * Use the user's name for the utility as argv[0], just like the 208 * shell. Echo is the default. Set up pointers for the user's 209 * arguments. 210 */ 211 if (*argv == NULL) 212 cnt = strlen(*bxp++ = echo); 213 else { 214 do { 215 if (Jflag && strcmp(*argv, replstr) == 0) { 216 char **avj; 217 jfound = 1; 218 argv++; 219 for (avj = argv; *avj; avj++) 220 cnt += strlen(*avj) + 1; 221 break; 222 } 223 cnt += strlen(*bxp++ = *argv) + 1; 224 } while (*++argv != NULL); 225 } 226 227 /* 228 * Set up begin/end/traversing pointers into the array. The -n 229 * count doesn't include the trailing NULL pointer, so the malloc 230 * added in an extra slot. 231 */ 232 expx = (xp = bxp) + nargs; 233 234 /* 235 * Allocate buffer space for the arguments read from stdin and the 236 * trailing NULL. Buffer space is defined as the default or specified 237 * space, minus the length of the utility name and arguments. Set up 238 * begin/end/traversing pointers into the array. The -s count does 239 * include the trailing NULL, so the malloc didn't add in an extra 240 * slot. 241 */ 242 nline -= cnt; 243 if (nline <= 0) 244 errx(1, "insufficient space for command"); 245 246 if ((bbp = malloc((size_t)(nline + 1))) == NULL) 247 errx(1, "malloc failed"); 248 ebp = (argp = p = bbp) + nline - 1; 249 for (;;) 250 parse_input(argc, argv); 251 } 252 253 static void 254 parse_input(int argc, char *argv[]) 255 { 256 int ch, foundeof; 257 char **avj; 258 259 foundeof = 0; 260 261 switch(ch = getchar()) { 262 case EOF: 263 /* No arguments since last exec. */ 264 if (p == bbp) { 265 waitchildren(*argv, 1); 266 exit(rval); 267 } 268 goto arg1; 269 case ' ': 270 case '\t': 271 /* Quotes escape tabs and spaces. */ 272 if (insingle || indouble || zflag) 273 goto addch; 274 goto arg2; 275 case '\0': 276 if (zflag) 277 goto arg2; 278 goto addch; 279 case '\n': 280 count++; 281 if (zflag) 282 goto addch; 283 284 /* Quotes do not escape newlines. */ 285 arg1: if (insingle || indouble) 286 errx(1, "unterminated quote"); 287 arg2: 288 foundeof = *eofstr != '\0' && 289 strcmp(argp, eofstr) == 0; 290 291 /* Do not make empty args unless they are quoted */ 292 if ((argp != p || wasquoted) && !foundeof) { 293 *p++ = '\0'; 294 *xp++ = argp; 295 if (Iflag) { 296 size_t curlen; 297 298 if (inpline == NULL) 299 curlen = 0; 300 else { 301 /* 302 * If this string is not zero 303 * length, append a space for 304 * separation before the next 305 * argument. 306 */ 307 if ((curlen = strlen(inpline))) 308 strcat(inpline, " "); 309 } 310 curlen++; 311 /* 312 * Allocate enough to hold what we will 313 * be holding in a second, and to append 314 * a space next time through, if we have 315 * to. 316 */ 317 inpline = realloc(inpline, curlen + 2 + 318 strlen(argp)); 319 if (inpline == NULL) 320 errx(1, "realloc failed"); 321 if (curlen == 1) 322 strcpy(inpline, argp); 323 else 324 strcat(inpline, argp); 325 } 326 } 327 328 /* 329 * If max'd out on args or buffer, or reached EOF, 330 * run the command. If xflag and max'd out on buffer 331 * but not on args, object. Having reached the limit 332 * of input lines, as specified by -L is the same as 333 * maxing out on arguments. 334 */ 335 if (xp == expx || p > ebp || ch == EOF || 336 (Lflag <= count && xflag) || foundeof) { 337 if (xflag && xp != expx && p > ebp) 338 errx(1, "insufficient space for arguments"); 339 if (jfound) { 340 for (avj = argv; *avj; avj++) 341 *xp++ = *avj; 342 } 343 prerun(argc, av); 344 if (ch == EOF || foundeof) { 345 waitchildren(*argv, 1); 346 exit(rval); 347 } 348 p = bbp; 349 xp = bxp; 350 count = 0; 351 } 352 argp = p; 353 wasquoted = 0; 354 break; 355 case '\'': 356 if (indouble || zflag) 357 goto addch; 358 insingle = !insingle; 359 wasquoted = 1; 360 break; 361 case '"': 362 if (insingle || zflag) 363 goto addch; 364 indouble = !indouble; 365 wasquoted = 1; 366 break; 367 case '\\': 368 if (zflag) 369 goto addch; 370 /* Backslash escapes anything, is escaped by quotes. */ 371 if (!insingle && !indouble && (ch = getchar()) == EOF) 372 errx(1, "backslash at EOF"); 373 /* FALLTHROUGH */ 374 default: 375 addch: if (p < ebp) { 376 *p++ = ch; 377 break; 378 } 379 380 /* If only one argument, not enough buffer space. */ 381 if (bxp == xp) 382 errx(1, "insufficient space for argument"); 383 /* Didn't hit argument limit, so if xflag object. */ 384 if (xflag) 385 errx(1, "insufficient space for arguments"); 386 387 if (jfound) { 388 for (avj = argv; *avj; avj++) 389 *xp++ = *avj; 390 } 391 prerun(argc, av); 392 xp = bxp; 393 cnt = ebp - argp; 394 memcpy(bbp, argp, (size_t)cnt); 395 p = (argp = bbp) + cnt; 396 *p++ = ch; 397 break; 398 } 399 return; 400 } 401 402 /* 403 * Do things necessary before run()'ing, such as -I substitution, 404 * and then call run(). 405 */ 406 static void 407 prerun(int argc, char *argv[]) 408 { 409 char **tmp, **tmp2, **avj; 410 int repls; 411 412 repls = Rflag; 413 414 if (argc == 0 || repls == 0) { 415 *xp = NULL; 416 run(argv); 417 return; 418 } 419 420 avj = argv; 421 422 /* 423 * Allocate memory to hold the argument list, and 424 * a NULL at the tail. 425 */ 426 tmp = malloc((argc + 1) * sizeof(char**)); 427 if (tmp == NULL) 428 errx(1, "malloc failed"); 429 tmp2 = tmp; 430 431 /* 432 * Save the first argument and iterate over it, we 433 * cannot do strnsubst() to it. 434 */ 435 if ((*tmp++ = strdup(*avj++)) == NULL) 436 errx(1, "strdup failed"); 437 438 /* 439 * For each argument to utility, if we have not used up 440 * the number of replacements we are allowed to do, and 441 * if the argument contains at least one occurrence of 442 * replstr, call strnsubst(), else just save the string. 443 * Iterations over elements of avj and tmp are done 444 * where appropriate. 445 */ 446 while (--argc) { 447 *tmp = *avj++; 448 if (repls && strstr(*tmp, replstr) != NULL) { 449 strnsubst(tmp++, replstr, inpline, (size_t)255); 450 repls--; 451 } else { 452 if ((*tmp = strdup(*tmp)) == NULL) 453 errx(1, "strdup failed"); 454 tmp++; 455 } 456 } 457 458 /* 459 * Run it. 460 */ 461 *tmp = NULL; 462 run(tmp2); 463 464 /* 465 * Walk from the tail to the head, free along the way. 466 */ 467 for (; tmp2 != tmp; tmp--) 468 free(*tmp); 469 /* 470 * Now free the list itself. 471 */ 472 free(tmp2); 473 474 /* 475 * Free the input line buffer, if we have one. 476 */ 477 if (inpline != NULL) { 478 free(inpline); 479 inpline = NULL; 480 } 481 } 482 483 static void 484 run(char **argv) 485 { 486 char **avec; 487 pid_t pid; 488 489 /* 490 * If the user wants to be notified of each command before it is 491 * executed, notify them. If they want the notification to be 492 * followed by a prompt, then prompt them. 493 */ 494 if (tflag || pflag) { 495 (void)fprintf(stderr, "%s", *argv); 496 for (avec = argv + 1; *avec != NULL; ++avec) 497 (void)fprintf(stderr, " %s", *avec); 498 /* 499 * If the user has asked to be prompted, do so. 500 */ 501 #ifndef BOOTSTRAPPING 502 if (pflag) 503 /* 504 * If they asked not to exec, return without execution 505 * but if they asked to, go to the execution. If we 506 * could not open their tty, break the switch and drop 507 * back to -t behaviour. 508 */ 509 switch (prompt()) { 510 case 0: 511 return; 512 case 1: 513 goto exec; 514 case 2: 515 break; 516 } 517 #endif 518 (void)fprintf(stderr, "\n"); 519 (void)fflush(stderr); 520 } 521 #ifndef BOOTSTRAPPING 522 exec: 523 #endif 524 childerr = 0; 525 switch(pid = vfork()) { 526 case -1: 527 err(1, "vfork"); 528 case 0: 529 close(0); 530 if (oflag) { 531 if (open("/dev/tty", O_RDONLY) == -1) 532 err(1, "open /dev/tty"); 533 } else { 534 if (open("/dev/null", O_RDONLY) == -1) 535 err(1, "open /dev/null"); 536 } 537 execvp(argv[0], argv); 538 childerr = errno; 539 _exit(1); 540 } 541 curprocs++; 542 waitchildren(*argv, 0); 543 } 544 545 /* 546 * Handle child processes. 547 */ 548 static void 549 waitchildren(const char *name, int waitall) 550 { 551 pid_t pid; 552 int status; 553 554 while ((pid = wait3(&status, !waitall && curprocs < maxprocs ? 555 WNOHANG : 0, NULL)) > 0) { 556 curprocs--; 557 558 /* If we couldn't invoke the utility, exit. */ 559 if (childerr != 0) { 560 errno = childerr; 561 err(errno == ENOENT ? 127 : 126, "%s", name); 562 } 563 564 /* 565 * If utility signaled or exited with a value of 255, 566 * exit 1-125. 567 */ 568 if (WIFSIGNALED(status) || WEXITSTATUS(status) == 255) 569 exit(1); 570 if (WEXITSTATUS(status)) 571 rval = 1; 572 } 573 if (pid == -1 && errno != ECHILD) 574 err(1, "wait3"); 575 } 576 577 /* 578 * Prompt the user about running a command. 579 */ 580 #ifndef BOOTSTRAPPING 581 static int 582 prompt(void) 583 { 584 regex_t cre; 585 size_t rsize; 586 int match; 587 char *response; 588 FILE *ttyfp; 589 590 if ((ttyfp = fopen(_PATH_TTY, "r")) == NULL) 591 return (2); /* Indicate that the TTY failed to open. */ 592 (void)fprintf(stderr, "?..."); 593 (void)fflush(stderr); 594 if ((response = fgetln(ttyfp, &rsize)) == NULL || 595 regcomp(&cre, 596 nl_langinfo(YESEXPR), 597 REG_BASIC) != 0) { 598 (void)fclose(ttyfp); 599 return (0); 600 } 601 match = regexec(&cre, response, 0, NULL, 0); 602 (void)fclose(ttyfp); 603 regfree(&cre); 604 return (match == 0); 605 } 606 #endif 607 608 static void 609 usage(void) 610 { 611 fprintf(stderr, 612 "usage: xargs [-0opt] [-E eofstr] [-I replstr [-R replacements]] [-J replstr]\n" 613 " [-L number] [-n number [-x] [-P maxprocs] [-s size]\n" 614 " [utility [argument ...]]\n"); 615 exit(1); 616 } 617