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 37 #ifndef lint 38 static const char copyright[] = 39 "@(#) Copyright (c) 1990, 1993\n\ 40 The Regents of the University of California. All rights reserved.\n"; 41 #endif /* not lint */ 42 43 #ifndef lint 44 #if 0 45 static char sccsid[] = "@(#)xargs.c 8.1 (Berkeley) 6/6/93"; 46 #endif 47 static const char rcsid[] = 48 "$Id: xargs.c,v 1.6 1998/06/17 12:58:43 jkoshy Exp $"; 49 #endif /* not lint */ 50 51 #include <sys/types.h> 52 #include <sys/wait.h> 53 #include <err.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <unistd.h> 58 #include "pathnames.h" 59 60 int tflag, rval; 61 int zflag; 62 63 void run __P((char **)); 64 static void usage __P((void)); 65 66 int 67 main(argc, argv, env) 68 int argc; 69 char **argv, **env; 70 { 71 register int ch; 72 register char *p, *bbp, *ebp, **bxp, **exp, **xp; 73 int cnt, indouble, insingle, nargs, nflag, nline, xflag; 74 char **av, *argp, **ep = env; 75 long arg_max; 76 77 /* 78 * POSIX.2 limits the exec line length to ARG_MAX - 2K. Running that 79 * caused some E2BIG errors, so it was changed to ARG_MAX - 4K. Given 80 * that the smallest argument is 2 bytes in length, this means that 81 * the number of arguments is limited to: 82 * 83 * (ARG_MAX - 4K - LENGTH(utility + arguments)) / 2. 84 * 85 * We arbitrarily limit the number of arguments to 5000. This is 86 * allowed by POSIX.2 as long as the resulting minimum exec line is 87 * at least LINE_MAX. Realloc'ing as necessary is possible, but 88 * probably not worthwhile. 89 */ 90 nargs = 5000; 91 if ((arg_max = sysconf(_SC_ARG_MAX)) == -1) 92 errx(1, "sysconf(_SC_ARG_MAX) failed"); 93 nline = arg_max - 4 * 1024; 94 while (*ep) { 95 /* 1 byte for each '\0' */ 96 nline -= strlen(*ep++) + 1 + sizeof(*ep); 97 } 98 nflag = xflag = 0; 99 while ((ch = getopt(argc, argv, "0n:s:tx")) != -1) 100 switch(ch) { 101 case 'n': 102 nflag = 1; 103 if ((nargs = atoi(optarg)) <= 0) 104 errx(1, "illegal argument count"); 105 break; 106 case 's': 107 nline = atoi(optarg); 108 break; 109 case 't': 110 tflag = 1; 111 break; 112 case 'x': 113 xflag = 1; 114 break; 115 case '0': 116 zflag = 1; 117 break; 118 case '?': 119 default: 120 usage(); 121 } 122 argc -= optind; 123 argv += optind; 124 125 if (xflag && !nflag) 126 usage(); 127 128 /* 129 * Allocate pointers for the utility name, the utility arguments, 130 * the maximum arguments to be read from stdin and the trailing 131 * NULL. 132 */ 133 if (!(av = bxp = 134 malloc((u_int)(1 + argc + nargs + 1) * sizeof(char **)))) 135 errx(1, "malloc"); 136 137 /* 138 * Use the user's name for the utility as argv[0], just like the 139 * shell. Echo is the default. Set up pointers for the user's 140 * arguments. 141 */ 142 if (!*argv) 143 cnt = strlen(*bxp++ = _PATH_ECHO); 144 else { 145 cnt = 0; 146 do { 147 cnt += strlen(*bxp++ = *argv) + 1; 148 } while (*++argv); 149 } 150 151 /* 152 * Set up begin/end/traversing pointers into the array. The -n 153 * count doesn't include the trailing NULL pointer, so the malloc 154 * added in an extra slot. 155 */ 156 exp = (xp = bxp) + nargs; 157 158 /* 159 * Allocate buffer space for the arguments read from stdin and the 160 * trailing NULL. Buffer space is defined as the default or specified 161 * space, minus the length of the utility name and arguments. Set up 162 * begin/end/traversing pointers into the array. The -s count does 163 * include the trailing NULL, so the malloc didn't add in an extra 164 * slot. 165 */ 166 nline -= cnt; 167 if (nline <= 0) 168 errx(1, "insufficient space for command"); 169 170 if (!(bbp = malloc((u_int)nline + 1))) 171 errx(1, "malloc"); 172 ebp = (argp = p = bbp) + nline - 1; 173 174 for (insingle = indouble = 0;;) 175 switch(ch = getchar()) { 176 case EOF: 177 /* No arguments since last exec. */ 178 if (p == bbp) 179 exit(rval); 180 181 /* Nothing since end of last argument. */ 182 if (argp == p) { 183 *xp = NULL; 184 run(av); 185 exit(rval); 186 } 187 goto arg1; 188 case ' ': 189 case '\t': 190 /* Quotes escape tabs and spaces. */ 191 if (insingle || indouble || zflag) 192 goto addch; 193 goto arg2; 194 case '\0': 195 if (zflag) 196 goto arg2; 197 goto addch; 198 case '\n': 199 if (zflag) 200 goto addch; 201 202 /* Empty lines are skipped. */ 203 if (argp == p) 204 continue; 205 206 /* Quotes do not escape newlines. */ 207 arg1: if (insingle || indouble) 208 errx(1, "unterminated quote"); 209 210 arg2: *p = '\0'; 211 *xp++ = argp; 212 213 /* 214 * If max'd out on args or buffer, or reached EOF, 215 * run the command. If xflag and max'd out on buffer 216 * but not on args, object. 217 */ 218 if (xp == exp || p == ebp || ch == EOF) { 219 if (xflag && xp != exp && p == ebp) 220 errx(1, "insufficient space for arguments"); 221 *xp = NULL; 222 run(av); 223 if (ch == EOF) 224 exit(rval); 225 p = bbp; 226 xp = bxp; 227 } else 228 ++p; 229 argp = p; 230 break; 231 case '\'': 232 if (indouble || zflag) 233 goto addch; 234 insingle = !insingle; 235 break; 236 case '"': 237 if (insingle || zflag) 238 goto addch; 239 indouble = !indouble; 240 break; 241 case '\\': 242 if (zflag) 243 goto addch; 244 /* Backslash escapes anything, is escaped by quotes. */ 245 if (!insingle && !indouble && (ch = getchar()) == EOF) 246 errx(1, "backslash at EOF"); 247 /* FALLTHROUGH */ 248 default: 249 addch: if (p < ebp) { 250 *p++ = ch; 251 break; 252 } 253 254 /* If only one argument, not enough buffer space. */ 255 if (bxp == xp) 256 errx(1, "insufficient space for argument"); 257 /* Didn't hit argument limit, so if xflag object. */ 258 if (xflag) 259 errx(1, "insufficient space for arguments"); 260 261 *xp = NULL; 262 run(av); 263 xp = bxp; 264 cnt = ebp - argp; 265 bcopy(argp, bbp, cnt); 266 p = (argp = bbp) + cnt; 267 *p++ = ch; 268 break; 269 } 270 /* NOTREACHED */ 271 } 272 273 void 274 run(argv) 275 char **argv; 276 { 277 volatile int noinvoke; 278 register char **p; 279 pid_t pid; 280 int status; 281 282 if (tflag) { 283 (void)fprintf(stderr, "%s", *argv); 284 for (p = argv + 1; *p; ++p) 285 (void)fprintf(stderr, " %s", *p); 286 (void)fprintf(stderr, "\n"); 287 (void)fflush(stderr); 288 } 289 noinvoke = 0; 290 switch(pid = fork()) { 291 case -1: 292 err(1, "fork"); 293 case 0: 294 execvp(argv[0], argv); 295 warn("%s", argv[0]); 296 noinvoke = 1; 297 _exit(1); 298 } 299 pid = waitpid(pid, &status, 0); 300 if (pid == -1) 301 err(1, "waitpid"); 302 /* If we couldn't invoke the utility, exit 127. */ 303 if (noinvoke) 304 exit(127); 305 /* If utility signaled or exited with a value of 255, exit 1-125. */ 306 if (WIFSIGNALED(status) || WEXITSTATUS(status) == 255) 307 exit(1); 308 if (WEXITSTATUS(status)) 309 rval = 1; 310 } 311 312 static void 313 usage() 314 { 315 (void)fprintf(stderr, 316 "usage: xargs [-0] [-t] [-n number [-x]] [-s size] [utility [argument ...]]\n"); 317 exit(1); 318 } 319