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bf16eb5f WJ |
1 | /*- |
2 | * Copyright (c) 1990 The Regents of the University of California. | |
3 | * 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 | char copyright[] = | |
39 | "@(#) Copyright (c) 1990 The Regents of the University of California.\n\ | |
40 | All rights reserved.\n"; | |
41 | #endif /* not lint */ | |
42 | ||
43 | #ifndef lint | |
44 | static char sccsid[] = "@(#)xargs.c 5.11 (Berkeley) 6/19/91"; | |
45 | #endif /* not lint */ | |
46 | ||
47 | #include <sys/types.h> | |
48 | #include <sys/wait.h> | |
49 | #include <errno.h> | |
50 | #include <stdio.h> | |
51 | #include <stdlib.h> | |
52 | #include <string.h> | |
53 | #include <unistd.h> | |
54 | #include <limits.h> | |
55 | #include "pathnames.h" | |
56 | ||
57 | int fflag, tflag; | |
58 | void err __P((const char *, ...)); | |
59 | void run(), usage(); | |
60 | ||
61 | main(argc, argv) | |
62 | int argc; | |
63 | char **argv; | |
64 | { | |
65 | extern int optind; | |
66 | extern char *optarg; | |
67 | register int ch; | |
68 | register char *p, *bbp, *ebp, **bxp, **exp, **xp; | |
69 | int cnt, indouble, insingle, nargs, nflag, nline, xflag; | |
70 | char **av, *argp; | |
71 | ||
72 | /* | |
73 | * POSIX.2 limits the exec line length to ARG_MAX - 2K. Running that | |
74 | * caused some E2BIG errors, so it was changed to ARG_MAX - 4K. Given | |
75 | * that the smallest argument is 2 bytes in length, this means that | |
76 | * the number of arguments is limited to: | |
77 | * | |
78 | * (ARG_MAX - 4K - LENGTH(utility + arguments)) / 2. | |
79 | * | |
80 | * We arbitrarily limit the number of arguments to 5000. This is | |
81 | * allowed by POSIX.2 as long as the resulting minimum exec line is | |
82 | * at least LINE_MAX. Realloc'ing as necessary is possible, but | |
83 | * probably not worthwhile. | |
84 | */ | |
85 | nargs = 5000; | |
86 | nline = ARG_MAX - 4 * 1024; | |
87 | nflag = xflag = 0; | |
88 | while ((ch = getopt(argc, argv, "fn:s:tx")) != EOF) | |
89 | switch(ch) { | |
90 | case 'f': | |
91 | fflag = 1; | |
92 | break; | |
93 | case 'n': | |
94 | nflag = 1; | |
95 | if ((nargs = atoi(optarg)) <= 0) | |
96 | err("illegal argument count"); | |
97 | break; | |
98 | case 's': | |
99 | nline = atoi(optarg); | |
100 | break; | |
101 | case 't': | |
102 | tflag = 1; | |
103 | break; | |
104 | case 'x': | |
105 | xflag = 1; | |
106 | break; | |
107 | case '?': | |
108 | default: | |
109 | usage(); | |
110 | } | |
111 | argc -= optind; | |
112 | argv += optind; | |
113 | ||
114 | if (xflag && !nflag) | |
115 | usage(); | |
116 | ||
117 | /* | |
118 | * Allocate pointers for the utility name, the utility arguments, | |
119 | * the maximum arguments to be read from stdin and the trailing | |
120 | * NULL. | |
121 | */ | |
122 | if (!(av = bxp = | |
123 | malloc((u_int)(1 + argc + nargs + 1) * sizeof(char **)))) | |
124 | err("%s", strerror(errno)); | |
125 | ||
126 | /* | |
127 | * Use the user's name for the utility as argv[0], just like the | |
128 | * shell. Echo is the default. Set up pointers for the user's | |
129 | * arguments. | |
130 | */ | |
131 | if (!*argv) | |
132 | cnt = strlen(*bxp++ = _PATH_ECHO); | |
133 | else { | |
134 | cnt = 0; | |
135 | do { | |
136 | cnt += strlen(*bxp++ = *argv) + 1; | |
137 | } while (*++argv); | |
138 | } | |
139 | ||
140 | /* | |
141 | * Set up begin/end/traversing pointers into the array. The -n | |
142 | * count doesn't include the trailing NULL pointer, so the malloc | |
143 | * added in an extra slot. | |
144 | */ | |
145 | exp = (xp = bxp) + nargs; | |
146 | ||
147 | /* | |
148 | * Allocate buffer space for the arguments read from stdin and the | |
149 | * trailing NULL. Buffer space is defined as the default or specified | |
150 | * space, minus the length of the utility name and arguments. Set up | |
151 | * begin/end/traversing pointers into the array. The -s count does | |
152 | * include the trailing NULL, so the malloc didn't add in an extra | |
153 | * slot. | |
154 | */ | |
155 | nline -= cnt; | |
156 | if (nline <= 0) | |
157 | err("insufficient space for command"); | |
158 | ||
159 | if (!(bbp = malloc((u_int)nline + 1))) | |
160 | err("%s", strerror(errno)); | |
161 | ebp = (argp = p = bbp) + nline - 1; | |
162 | ||
163 | for (insingle = indouble = 0;;) | |
164 | switch(ch = getchar()) { | |
165 | case EOF: | |
166 | /* No arguments since last exec. */ | |
167 | if (p == bbp) | |
168 | exit(0); | |
169 | ||
170 | /* Nothing since end of last argument. */ | |
171 | if (argp == p) { | |
172 | *xp = NULL; | |
173 | run(av); | |
174 | exit(0); | |
175 | } | |
176 | goto arg1; | |
177 | case ' ': | |
178 | case '\t': | |
179 | /* Quotes escape tabs and spaces. */ | |
180 | if (insingle || indouble) | |
181 | goto addch; | |
182 | goto arg2; | |
183 | case '\n': | |
184 | /* Empty lines are skipped. */ | |
185 | if (argp == p) | |
186 | continue; | |
187 | ||
188 | /* Quotes do not escape newlines. */ | |
189 | arg1: if (insingle || indouble) | |
190 | err("unterminated quote"); | |
191 | ||
192 | arg2: *p = '\0'; | |
193 | *xp++ = argp; | |
194 | ||
195 | /* | |
196 | * If max'd out on args or buffer, or reached EOF, | |
197 | * run the command. If xflag and max'd out on buffer | |
198 | * but not on args, object. | |
199 | */ | |
200 | if (xp == exp || p == ebp || ch == EOF) { | |
201 | if (xflag && xp != exp && p == ebp) | |
202 | err("insufficient space for arguments"); | |
203 | *xp = NULL; | |
204 | run(av); | |
205 | if (ch == EOF) | |
206 | exit(0); | |
207 | p = bbp; | |
208 | xp = bxp; | |
209 | } else | |
210 | ++p; | |
211 | argp = p; | |
212 | break; | |
213 | case '\'': | |
214 | if (indouble) | |
215 | goto addch; | |
216 | insingle = !insingle; | |
217 | break; | |
218 | case '"': | |
219 | if (insingle) | |
220 | goto addch; | |
221 | indouble = !indouble; | |
222 | break; | |
223 | case '\\': | |
224 | /* Backslash escapes anything, is escaped by quotes. */ | |
225 | if (!insingle && !indouble && (ch = getchar()) == EOF) | |
226 | err("backslash at EOF"); | |
227 | /* FALLTHROUGH */ | |
228 | default: | |
229 | addch: if (p < ebp) { | |
230 | *p++ = ch; | |
231 | break; | |
232 | } | |
233 | ||
234 | /* If only one argument, not enough buffer space. */ | |
235 | if (bxp == xp) | |
236 | err("insufficient space for argument"); | |
237 | /* Didn't hit argument limit, so if xflag object. */ | |
238 | if (xflag) | |
239 | err("insufficient space for arguments"); | |
240 | ||
241 | *xp = NULL; | |
242 | run(av); | |
243 | xp = bxp; | |
244 | cnt = ebp - argp; | |
245 | bcopy(argp, bbp, cnt); | |
246 | p = (argp = bbp) + cnt; | |
247 | *p++ = ch; | |
248 | break; | |
249 | } | |
250 | /* NOTREACHED */ | |
251 | } | |
252 | ||
253 | void | |
254 | run(argv) | |
255 | char **argv; | |
256 | { | |
257 | register char **p; | |
258 | pid_t pid; | |
259 | volatile int noinvoke; | |
260 | int status; | |
261 | ||
262 | if (tflag) { | |
263 | (void)fprintf(stderr, "%s", *argv); | |
264 | for (p = argv + 1; *p; ++p) | |
265 | (void)fprintf(stderr, " %s", *p); | |
266 | (void)fprintf(stderr, "\n"); | |
267 | (void)fflush(stderr); | |
268 | } | |
269 | noinvoke = 0; | |
270 | switch(pid = vfork()) { | |
271 | case -1: | |
272 | err("vfork: %s", strerror(errno)); | |
273 | case 0: | |
274 | execvp(argv[0], argv); | |
275 | (void)fprintf(stderr, | |
276 | "xargs: %s: %s.\n", argv[0], strerror(errno)); | |
277 | noinvoke = 1; | |
278 | _exit(1); | |
279 | } | |
280 | pid = waitpid(pid, &status, 0); | |
281 | if (pid == -1) | |
282 | err("waitpid: %s", strerror(errno)); | |
283 | /* | |
284 | * If we couldn't invoke the utility or the utility didn't exit | |
285 | * properly, quit with 127. | |
286 | * Otherwise, if not specified otherwise, and the utility exits | |
287 | * non-zero, exit with that value. | |
288 | */ | |
289 | if (noinvoke || !WIFEXITED(status) || WIFSIGNALED(status)) | |
290 | exit(127); | |
291 | if (!fflag && WEXITSTATUS(status)) | |
292 | exit(WEXITSTATUS(status)); | |
293 | } | |
294 | ||
295 | void | |
296 | usage() | |
297 | { | |
298 | (void)fprintf(stderr, | |
299 | "usage: xargs [-ft] [[-x] -n number] [-s size] [utility [argument ...]]\n"); | |
300 | exit(1); | |
301 | } | |
302 | ||
303 | #if __STDC__ | |
304 | #include <stdarg.h> | |
305 | #else | |
306 | #include <varargs.h> | |
307 | #endif | |
308 | ||
309 | void | |
310 | #if __STDC__ | |
311 | err(const char *fmt, ...) | |
312 | #else | |
313 | err(fmt, va_alist) | |
314 | char *fmt; | |
315 | va_dcl | |
316 | #endif | |
317 | { | |
318 | va_list ap; | |
319 | #if __STDC__ | |
320 | va_start(ap, fmt); | |
321 | #else | |
322 | va_start(ap); | |
323 | #endif | |
324 | (void)fprintf(stderr, "xargs: "); | |
325 | (void)vfprintf(stderr, fmt, ap); | |
326 | va_end(ap); | |
327 | (void)fprintf(stderr, "\n"); | |
328 | exit(1); | |
329 | /* NOTREACHED */ | |
330 | } |