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. 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. 23 * 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 34 * SUCH DAMAGE. 35 * 36 * $xMach: xargs.c,v 1.6 2002/02/23 05:27:47 tim Exp $ 37 */ 38 39 #if 0 40 #ifndef lint 41 static const char copyright[] = 42 "@(#) Copyright (c) 1990, 1993\n\ 43 The Regents of the University of California. All rights reserved.\n"; 44 #endif /* not lint */ 45 46 #ifndef lint 47 static char sccsid[] = "@(#)xargs.c 8.1 (Berkeley) 6/6/93"; 48 #endif /* not lint */ 49 #endif 50 #include <sys/cdefs.h> 51 __FBSDID("$FreeBSD$"); 52 53 #include <sys/param.h> 54 #include <sys/wait.h> 55 56 #include <err.h> 57 #include <errno.h> 58 #include <fcntl.h> 59 #include <langinfo.h> 60 #include <locale.h> 61 #include <paths.h> 62 #include <regex.h> 63 #include <stdio.h> 64 #include <stdlib.h> 65 #include <string.h> 66 #include <unistd.h> 67 68 #include "pathnames.h" 69 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); 77 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, wasquoted, xflag; 84 static int curprocs, maxprocs; 85 86 static volatile int childerr; 87 88 extern char **environ; 89 90 int 91 main(int argc, char *argv[]) 92 { 93 long arg_max; 94 int ch, Jflag, nargs, nflag, nline; 95 size_t linelen; 96 char *endptr; 97 98 inpline = replstr = NULL; 99 ep = environ; 100 eofstr = ""; 101 Jflag = nflag = 0; 102 103 (void)setlocale(LC_ALL, ""); 104 105 /* 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: 110 * 111 * (ARG_MAX - 4K - LENGTH(utility + arguments)) / 2. 112 * 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. 117 */ 118 nargs = 5000; 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); 125 } 126 maxprocs = 1; 127 while ((ch = getopt(argc, argv, "0E:I:J:L:n:oP:pR:s:tx")) != -1) 128 switch(ch) { 129 case 'E': 130 eofstr = optarg; 131 break; 132 case 'I': 133 Jflag = 0; 134 Iflag = 1; 135 Lflag = 1; 136 replstr = optarg; 137 break; 138 case 'J': 139 Iflag = 0; 140 Jflag = 1; 141 replstr = optarg; 142 break; 143 case 'L': 144 Lflag = atoi(optarg); 145 break; 146 case 'n': 147 nflag = 1; 148 if ((nargs = atoi(optarg)) <= 0) 149 errx(1, "illegal argument count"); 150 break; 151 case 'o': 152 oflag = 1; 153 break; 154 case 'P': 155 if ((maxprocs = atoi(optarg)) <= 0) 156 errx(1, "max. processes must be >0"); 157 break; 158 case 'p': 159 pflag = 1; 160 break; 161 case 'R': 162 Rflag = strtol(optarg, &endptr, 10); 163 if (*endptr != '\0') 164 errx(1, "replacements must be a number"); 165 break; 166 case 's': 167 nline = atoi(optarg); 168 break; 169 case 't': 170 tflag = 1; 171 break; 172 case 'x': 173 xflag = 1; 174 break; 175 case '0': 176 zflag = 1; 177 break; 178 case '?': 179 default: 180 usage(); 181 } 182 argc -= optind; 183 argv += optind; 184 185 if (!Iflag && Rflag) 186 usage(); 187 if (Iflag && !Rflag) 188 Rflag = 5; 189 if (xflag && !nflag) 190 usage(); 191 if (Iflag || Lflag) 192 xflag = 1; 193 if (replstr != NULL && *replstr == '\0') 194 errx(1, "replstr may not be empty"); 195 196 /* 197 * Allocate pointers for the utility name, the utility arguments, 198 * the maximum arguments to be read from stdin and the trailing 199 * NULL. 200 */ 201 linelen = 1 + argc + nargs + 1; 202 if ((av = bxp = malloc(linelen * sizeof(char **))) == NULL) 203 errx(1, "malloc failed"); 204 205 /* 206 * Use the user's name for the utility as argv[0], just like the 207 * shell. Echo is the default. Set up pointers for the user's 208 * arguments. 209 */ 210 if (*argv == NULL) 211 cnt = strlen(*bxp++ = echo); 212 else { 213 do { 214 if (Jflag && strcmp(*argv, replstr) == 0) { 215 char **avj; 216 jfound = 1; 217 argv++; 218 for (avj = argv; *avj; avj++) 219 cnt += strlen(*avj) + 1; 220 break; 221 } 222 cnt += strlen(*bxp++ = *argv) + 1; 223 } while (*++argv != NULL); 224 } 225 226 /* 227 * Set up begin/end/traversing pointers into the array. The -n 228 * count doesn't include the trailing NULL pointer, so the malloc 229 * added in an extra slot. 230 */ 231 endxp = (xp = bxp) + nargs; 232 233 /* 234 * Allocate buffer space for the arguments read from stdin and the 235 * trailing NULL. Buffer space is defined as the default or specified 236 * space, minus the length of the utility name and arguments. Set up 237 * begin/end/traversing pointers into the array. The -s count does 238 * include the trailing NULL, so the malloc didn't add in an extra 239 * slot. 240 */ 241 nline -= cnt; 242 if (nline <= 0) 243 errx(1, "insufficient space for command"); 244 245 if ((bbp = malloc((size_t)(nline + 1))) == NULL) 246 errx(1, "malloc failed"); 247 ebp = (argp = p = bbp) + nline - 1; 248 for (;;) 249 parse_input(argc, argv); 250 } 251 252 static void 253 parse_input(int argc, char *argv[]) 254 { 255 int ch, foundeof; 256 char **avj; 257 258 foundeof = 0; 259 260 switch(ch = getchar()) { 261 case EOF: 262 /* No arguments since last exec. */ 263 if (p == bbp) { 264 waitchildren(*argv, 1); 265 exit(rval); 266 } 267 goto arg1; 268 case ' ': 269 case '\t': 270 /* Quotes escape tabs and spaces. */ 271 if (insingle || indouble || zflag) 272 goto addch; 273 goto arg2; 274 case '\0': 275 if (zflag) { 276 /* 277 * Increment 'count', so that nulls will be treated 278 * as end-of-line, as well as end-of-argument. This 279 * is needed so -0 works properly with -I and -L. 280 */ 281 count++; 282 goto arg2; 283 } 284 goto addch; 285 case '\n': 286 if (zflag) 287 goto addch; 288 count++; /* Indicate end-of-line (used by -L) */ 289 290 /* Quotes do not escape newlines. */ 291 arg1: if (insingle || indouble) 292 errx(1, "unterminated quote"); 293 arg2: 294 foundeof = *eofstr != '\0' && 295 strcmp(argp, eofstr) == 0; 296 297 /* Do not make empty args unless they are quoted */ 298 if ((argp != p || wasquoted) && !foundeof) { 299 *p++ = '\0'; 300 *xp++ = argp; 301 if (Iflag) { 302 size_t curlen; 303 304 if (inpline == NULL) 305 curlen = 0; 306 else { 307 /* 308 * If this string is not zero 309 * length, append a space for 310 * separation before the next 311 * argument. 312 */ 313 if ((curlen = strlen(inpline))) 314 strcat(inpline, " "); 315 } 316 curlen++; 317 /* 318 * Allocate enough to hold what we will 319 * be holding in a second, and to append 320 * a space next time through, if we have 321 * to. 322 */ 323 inpline = realloc(inpline, curlen + 2 + 324 strlen(argp)); 325 if (inpline == NULL) 326 errx(1, "realloc failed"); 327 if (curlen == 1) 328 strcpy(inpline, argp); 329 else 330 strcat(inpline, argp); 331 } 332 } 333 334 /* 335 * If max'd out on args or buffer, or reached EOF, 336 * run the command. If xflag and max'd out on buffer 337 * but not on args, object. Having reached the limit 338 * of input lines, as specified by -L is the same as 339 * maxing out on arguments. 340 */ 341 if (xp == endxp || p > ebp || ch == EOF || 342 (Lflag <= count && xflag) || foundeof) { 343 if (xflag && xp != endxp && p > ebp) 344 errx(1, "insufficient space for arguments"); 345 if (jfound) { 346 for (avj = argv; *avj; avj++) 347 *xp++ = *avj; 348 } 349 prerun(argc, av); 350 if (ch == EOF || foundeof) { 351 waitchildren(*argv, 1); 352 exit(rval); 353 } 354 p = bbp; 355 xp = bxp; 356 count = 0; 357 } 358 argp = p; 359 wasquoted = 0; 360 break; 361 case '\'': 362 if (indouble || zflag) 363 goto addch; 364 insingle = !insingle; 365 wasquoted = 1; 366 break; 367 case '"': 368 if (insingle || zflag) 369 goto addch; 370 indouble = !indouble; 371 wasquoted = 1; 372 break; 373 case '\\': 374 if (zflag) 375 goto addch; 376 /* Backslash escapes anything, is escaped by quotes. */ 377 if (!insingle && !indouble && (ch = getchar()) == EOF) 378 errx(1, "backslash at EOF"); 379 /* FALLTHROUGH */ 380 default: 381 addch: if (p < ebp) { 382 *p++ = ch; 383 break; 384 } 385 386 /* If only one argument, not enough buffer space. */ 387 if (bxp == xp) 388 errx(1, "insufficient space for argument"); 389 /* Didn't hit argument limit, so if xflag object. */ 390 if (xflag) 391 errx(1, "insufficient space for arguments"); 392 393 if (jfound) { 394 for (avj = argv; *avj; avj++) 395 *xp++ = *avj; 396 } 397 prerun(argc, av); 398 xp = bxp; 399 cnt = ebp - argp; 400 memcpy(bbp, argp, (size_t)cnt); 401 p = (argp = bbp) + cnt; 402 *p++ = ch; 403 break; 404 } 405 } 406 407 /* 408 * Do things necessary before run()'ing, such as -I substitution, 409 * and then call run(). 410 */ 411 static void 412 prerun(int argc, char *argv[]) 413 { 414 char **tmp, **tmp2, **avj; 415 int repls; 416 417 repls = Rflag; 418 419 if (argc == 0 || repls == 0) { 420 *xp = NULL; 421 run(argv); 422 return; 423 } 424 425 avj = argv; 426 427 /* 428 * Allocate memory to hold the argument list, and 429 * a NULL at the tail. 430 */ 431 tmp = malloc((argc + 1) * sizeof(char**)); 432 if (tmp == NULL) 433 errx(1, "malloc failed"); 434 tmp2 = tmp; 435 436 /* 437 * Save the first argument and iterate over it, we 438 * cannot do strnsubst() to it. 439 */ 440 if ((*tmp++ = strdup(*avj++)) == NULL) 441 errx(1, "strdup failed"); 442 443 /* 444 * For each argument to utility, if we have not used up 445 * the number of replacements we are allowed to do, and 446 * if the argument contains at least one occurrence of 447 * replstr, call strnsubst(), else just save the string. 448 * Iterations over elements of avj and tmp are done 449 * where appropriate. 450 */ 451 while (--argc) { 452 *tmp = *avj++; 453 if (repls && strstr(*tmp, replstr) != NULL) { 454 strnsubst(tmp++, replstr, inpline, (size_t)255); 455 if (repls > 0) 456 repls--; 457 } else { 458 if ((*tmp = strdup(*tmp)) == NULL) 459 errx(1, "strdup failed"); 460 tmp++; 461 } 462 } 463 464 /* 465 * Run it. 466 */ 467 *tmp = NULL; 468 run(tmp2); 469 470 /* 471 * Walk from the tail to the head, free along the way. 472 */ 473 for (; tmp2 != tmp; tmp--) 474 free(*tmp); 475 /* 476 * Now free the list itself. 477 */ 478 free(tmp2); 479 480 /* 481 * Free the input line buffer, if we have one. 482 */ 483 if (inpline != NULL) { 484 free(inpline); 485 inpline = NULL; 486 } 487 } 488 489 static void 490 run(char **argv) 491 { 492 pid_t pid; 493 int fd; 494 char **avec; 495 496 /* 497 * If the user wants to be notified of each command before it is 498 * executed, notify them. If they want the notification to be 499 * followed by a prompt, then prompt them. 500 */ 501 if (tflag || pflag) { 502 (void)fprintf(stderr, "%s", *argv); 503 for (avec = argv + 1; *avec != NULL; ++avec) 504 (void)fprintf(stderr, " %s", *avec); 505 /* 506 * If the user has asked to be prompted, do so. 507 */ 508 if (pflag) 509 /* 510 * If they asked not to exec, return without execution 511 * but if they asked to, go to the execution. If we 512 * could not open their tty, break the switch and drop 513 * back to -t behaviour. 514 */ 515 switch (prompt()) { 516 case 0: 517 return; 518 case 1: 519 goto exec; 520 case 2: 521 break; 522 } 523 (void)fprintf(stderr, "\n"); 524 (void)fflush(stderr); 525 } 526 exec: 527 childerr = 0; 528 switch(pid = vfork()) { 529 case -1: 530 err(1, "vfork"); 531 case 0: 532 if (oflag) { 533 if ((fd = open(_PATH_TTY, O_RDONLY)) == -1) 534 err(1, "can't open /dev/tty"); 535 } else { 536 fd = open(_PATH_DEVNULL, O_RDONLY); 537 } 538 if (fd > STDIN_FILENO) { 539 if (dup2(fd, STDIN_FILENO) != 0) 540 err(1, "can't dup2 to stdin"); 541 close(fd); 542 } 543 execvp(argv[0], argv); 544 childerr = errno; 545 _exit(1); 546 } 547 curprocs++; 548 waitchildren(*argv, 0); 549 } 550 551 static void 552 waitchildren(const char *name, int waitall) 553 { 554 pid_t pid; 555 int status; 556 557 while ((pid = waitpid(-1, &status, !waitall && curprocs < maxprocs ? 558 WNOHANG : 0)) > 0) { 559 curprocs--; 560 /* If we couldn't invoke the utility, exit. */ 561 if (childerr != 0) { 562 errno = childerr; 563 err(errno == ENOENT ? 127 : 126, "%s", name); 564 } 565 /* 566 * If utility signaled or exited with a value of 255, 567 * exit 1-125. 568 */ 569 if (WIFSIGNALED(status) || WEXITSTATUS(status) == 255) 570 exit(1); 571 if (WEXITSTATUS(status)) 572 rval = 1; 573 } 574 if (pid == -1 && errno != ECHILD) 575 err(1, "wait3"); 576 } 577 578 /* 579 * Prompt the user about running a command. 580 */ 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, nl_langinfo(YESEXPR), REG_BASIC) != 0) { 596 (void)fclose(ttyfp); 597 return (0); 598 } 599 match = regexec(&cre, response, 0, NULL, 0); 600 (void)fclose(ttyfp); 601 regfree(&cre); 602 return (match == 0); 603 } 604 605 static void 606 usage(void) 607 { 608 fprintf(stderr, 609 "usage: xargs [-0opt] [-E eofstr] [-I replstr [-R replacements]] [-J replstr]\n" 610 " [-L number] [-n number [-x]] [-P maxprocs] [-s size]\n" 611 " [utility [argument ...]]\n"); 612 exit(1); 613 } 614