source: MondoRescue/branches/2.2.8.selinux/mindi-busybox/findutils/xargs.c@ 3341

Last change on this file since 3341 was 1765, checked in by Bruno Cornec, 18 years ago

Update to busybox 1.7.2
File size: 12.3 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * Mini xargs implementation for busybox
4 * Options are supported: "-prtx -n max_arg -s max_chars -e[ouf_str]"
5 *
6 * (C) 2002,2003 by Vladimir Oleynik <dzo@simtreas.ru>
7 *
8 * Special thanks
9 * - Mark Whitley and Glenn McGrath for stimulus to rewrite :)
10 * - Mike Rendell <michael@cs.mun.ca>
11 * and David MacKenzie <djm@gnu.ai.mit.edu>.
12 *
13 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
14 *
15 * xargs is described in the Single Unix Specification v3 at
16 * http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html
17 *
18 */
19
20#include "libbb.h"
21
22/* This is a NOEXEC applet. Be very careful! */
23
24
25/* COMPAT: SYSV version defaults size (and has a max value of) to 470.
26 We try to make it as large as possible. */
27#if !defined(ARG_MAX) && defined(_SC_ARG_MAX)
28#define ARG_MAX sysconf (_SC_ARG_MAX)
29#endif
30#ifndef ARG_MAX
31#define ARG_MAX 470
32#endif
33
34
35#ifdef TEST
36# ifndef ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION
37# define ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION 1
38# endif
39# ifndef ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
40# define ENABLE_FEATURE_XARGS_SUPPORT_QUOTES 1
41# endif
42# ifndef ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT
43# define ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT 1
44# endif
45# ifndef ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
46# define ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM 1
47# endif
48#endif
49
50/*
51 This function has special algorithm.
52 Don't use fork and include to main!
53*/
54static int xargs_exec(char **args)
55{
56 int status;
57
58 status = spawn_and_wait(args);
59 if (status < 0) {
60 bb_perror_msg("%s", args[0]);
61 return errno == ENOENT ? 127 : 126;
62 }
63 if (status == 255) {
64 bb_error_msg("%s: exited with status 255; aborting", args[0]);
65 return 124;
66 }
67/* Huh? I think we won't see this, ever. We don't wait with WUNTRACED!
68 if (WIFSTOPPED(status)) {
69 bb_error_msg("%s: stopped by signal %d",
70 args[0], WSTOPSIG(status));
71 return 125;
72 }
73*/
74 if (status >= 1000) {
75 bb_error_msg("%s: terminated by signal %d",
76 args[0], status - 1000);
77 return 125;
78 }
79 if (status)
80 return 123;
81 return 0;
82}
83
84
85typedef struct xlist_t {
86 struct xlist_t *link;
87 size_t length;
88 char xstr[1];
89} xlist_t;
90
91static smallint eof_stdin_detected;
92
93#define ISBLANK(c) ((c) == ' ' || (c) == '\t')
94#define ISSPACE(c) (ISBLANK(c) || (c) == '\n' || (c) == '\r' \
95 || (c) == '\f' || (c) == '\v')
96
97#if ENABLE_FEATURE_XARGS_SUPPORT_QUOTES
98static xlist_t *process_stdin(xlist_t *list_arg,
99 const char *eof_str, size_t mc, char *buf)
100{
101#define NORM 0
102#define QUOTE 1
103#define BACKSLASH 2
104#define SPACE 4
105
106 char *s = NULL; /* start word */
107 char *p = NULL; /* pointer to end word */
108 char q = '\0'; /* quote char */
109 char state = NORM;
110 char eof_str_detected = 0;
111 size_t line_l = 0; /* size loaded args line */
112 int c; /* current char */
113 xlist_t *cur;
114 xlist_t *prev;
115
116 prev = cur = list_arg;
117 while (1) {
118 if (!cur) break;
119 prev = cur;
120 line_l += cur->length;
121 cur = cur->link;
122 }
123
124 while (!eof_stdin_detected) {
125 c = getchar();
126 if (c == EOF) {
127 eof_stdin_detected = 1;
128 if (s)
129 goto unexpected_eof;
130 break;
131 }
132 if (eof_str_detected)
133 continue;
134 if (state == BACKSLASH) {
135 state = NORM;
136 goto set;
137 } else if (state == QUOTE) {
138 if (c != q)
139 goto set;
140 q = '\0';
141 state = NORM;
142 } else { /* if (state == NORM) */
143 if (ISSPACE(c)) {
144 if (s) {
145 unexpected_eof:
146 state = SPACE;
147 c = '\0';
148 goto set;
149 }
150 } else {
151 if (s == NULL)
152 s = p = buf;
153 if (c == '\\') {
154 state = BACKSLASH;
155 } else if (c == '\'' || c == '"') {
156 q = c;
157 state = QUOTE;
158 } else {
159 set:
160 if ((size_t)(p - buf) >= mc)
161 bb_error_msg_and_die("argument line too long");
162 *p++ = c;
163 }
164 }
165 }
166 if (state == SPACE) { /* word's delimiter or EOF detected */
167 if (q) {
168 bb_error_msg_and_die("unmatched %s quote",
169 q == '\'' ? "single" : "double");
170 }
171 /* word loaded */
172 if (eof_str) {
173 eof_str_detected = (strcmp(s, eof_str) == 0);
174 }
175 if (!eof_str_detected) {
176 size_t length = (p - buf);
177 /* Dont xzalloc - it can be quite big */
178 cur = xmalloc(offsetof(xlist_t, xstr) + length);
179 cur->link = NULL;
180 cur->length = length;
181 memcpy(cur->xstr, s, length);
182 if (prev == NULL) {
183 list_arg = cur;
184 } else {
185 prev->link = cur;
186 }
187 prev = cur;
188 line_l += length;
189 if (line_l > mc) {
190 /* stop memory usage :-) */
191 break;
192 }
193 }
194 s = NULL;
195 state = NORM;
196 }
197 }
198 return list_arg;
199}
200#else
201/* The variant does not support single quotes, double quotes or backslash */
202static xlist_t *process_stdin(xlist_t *list_arg,
203 const char *eof_str, size_t mc, char *buf)
204{
205
206 int c; /* current char */
207 char eof_str_detected = 0;
208 char *s = NULL; /* start word */
209 char *p = NULL; /* pointer to end word */
210 size_t line_l = 0; /* size loaded args line */
211 xlist_t *cur;
212 xlist_t *prev;
213
214 prev = cur = list_arg;
215 while (1) {
216 if (!cur) break;
217 prev = cur;
218 line_l += cur->length;
219 cur = cur->link;
220 }
221
222 while (!eof_stdin_detected) {
223 c = getchar();
224 if (c == EOF) {
225 eof_stdin_detected = 1;
226 }
227 if (eof_str_detected)
228 continue;
229 if (c == EOF || ISSPACE(c)) {
230 if (s == NULL)
231 continue;
232 c = EOF;
233 }
234 if (s == NULL)
235 s = p = buf;
236 if ((p - buf) >= mc)
237 bb_error_msg_and_die("argument line too long");
238 *p++ = (c == EOF ? '\0' : c);
239 if (c == EOF) { /* word's delimiter or EOF detected */
240 /* word loaded */
241 if (eof_str) {
242 eof_str_detected = (strcmp(s, eof_str) == 0);
243 }
244 if (!eof_str_detected) {
245 size_t length = (p - buf);
246 /* Dont xzalloc - it can be quite big */
247 cur = xmalloc(offsetof(xlist_t, xstr) + length);
248 cur->link = NULL;
249 cur->length = length;
250 memcpy(cur->xstr, s, length);
251 if (prev == NULL) {
252 list_arg = cur;
253 } else {
254 prev->link = cur;
255 }
256 prev = cur;
257 line_l += length;
258 if (line_l > mc) {
259 /* stop memory usage :-) */
260 break;
261 }
262 s = NULL;
263 }
264 }
265 }
266 return list_arg;
267}
268#endif /* FEATURE_XARGS_SUPPORT_QUOTES */
269
270
271#if ENABLE_FEATURE_XARGS_SUPPORT_CONFIRMATION
272/* Prompt the user for a response, and
273 if the user responds affirmatively, return true;
274 otherwise, return false. Uses "/dev/tty", not stdin. */
275static int xargs_ask_confirmation(void)
276{
277 FILE *tty_stream;
278 int c, savec;
279
280 tty_stream = xfopen(CURRENT_TTY, "r");
281 fputs(" ?...", stderr);
282 fflush(stderr);
283 c = savec = getc(tty_stream);
284 while (c != EOF && c != '\n')
285 c = getc(tty_stream);
286 fclose(tty_stream);
287 return (savec == 'y' || savec == 'Y');
288}
289#else
290# define xargs_ask_confirmation() 1
291#endif /* FEATURE_XARGS_SUPPORT_CONFIRMATION */
292
293#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
294static xlist_t *process0_stdin(xlist_t *list_arg,
295 const char *eof_str ATTRIBUTE_UNUSED, size_t mc, char *buf)
296{
297 int c; /* current char */
298 char *s = NULL; /* start word */
299 char *p = NULL; /* pointer to end word */
300 size_t line_l = 0; /* size loaded args line */
301 xlist_t *cur;
302 xlist_t *prev;
303
304 prev = cur = list_arg;
305 while (1) {
306 if (!cur) break;
307 prev = cur;
308 line_l += cur->length;
309 cur = cur->link;
310 }
311
312 while (!eof_stdin_detected) {
313 c = getchar();
314 if (c == EOF) {
315 eof_stdin_detected = 1;
316 if (s == NULL)
317 break;
318 c = '\0';
319 }
320 if (s == NULL)
321 s = p = buf;
322 if ((size_t)(p - buf) >= mc)
323 bb_error_msg_and_die("argument line too long");
324 *p++ = c;
325 if (c == '\0') { /* word's delimiter or EOF detected */
326 /* word loaded */
327 size_t length = (p - buf);
328 /* Dont xzalloc - it can be quite big */
329 cur = xmalloc(offsetof(xlist_t, xstr) + length);
330 cur->link = NULL;
331 cur->length = length;
332 memcpy(cur->xstr, s, length);
333 if (prev == NULL) {
334 list_arg = cur;
335 } else {
336 prev->link = cur;
337 }
338 prev = cur;
339 line_l += length;
340 if (line_l > mc) {
341 /* stop memory usage :-) */
342 break;
343 }
344 s = NULL;
345 }
346 }
347 return list_arg;
348}
349#endif /* FEATURE_XARGS_SUPPORT_ZERO_TERM */
350
351/* Correct regardless of combination of CONFIG_xxx */
352enum {
353 OPTBIT_VERBOSE = 0,
354 OPTBIT_NO_EMPTY,
355 OPTBIT_UPTO_NUMBER,
356 OPTBIT_UPTO_SIZE,
357 OPTBIT_EOF_STRING,
358 USE_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,)
359 USE_FEATURE_XARGS_SUPPORT_TERMOPT( OPTBIT_TERMINATE ,)
360 USE_FEATURE_XARGS_SUPPORT_ZERO_TERM( OPTBIT_ZEROTERM ,)
361
362 OPT_VERBOSE = 1<<OPTBIT_VERBOSE ,
363 OPT_NO_EMPTY = 1<<OPTBIT_NO_EMPTY ,
364 OPT_UPTO_NUMBER = 1<<OPTBIT_UPTO_NUMBER,
365 OPT_UPTO_SIZE = 1<<OPTBIT_UPTO_SIZE ,
366 OPT_EOF_STRING = 1<<OPTBIT_EOF_STRING ,
367 OPT_INTERACTIVE = USE_FEATURE_XARGS_SUPPORT_CONFIRMATION((1<<OPTBIT_INTERACTIVE)) + 0,
368 OPT_TERMINATE = USE_FEATURE_XARGS_SUPPORT_TERMOPT( (1<<OPTBIT_TERMINATE )) + 0,
369 OPT_ZEROTERM = USE_FEATURE_XARGS_SUPPORT_ZERO_TERM( (1<<OPTBIT_ZEROTERM )) + 0,
370};
371#define OPTION_STR "+trn:s:e::" \
372 USE_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \
373 USE_FEATURE_XARGS_SUPPORT_TERMOPT( "x") \
374 USE_FEATURE_XARGS_SUPPORT_ZERO_TERM( "0")
375
376int xargs_main(int argc, char **argv);
377int xargs_main(int argc, char **argv)
378{
379 char **args;
380 int i, n;
381 xlist_t *list = NULL;
382 xlist_t *cur;
383 int child_error = 0;
384 char *max_args, *max_chars;
385 int n_max_arg;
386 size_t n_chars = 0;
387 long orig_arg_max;
388 const char *eof_str = "_";
389 unsigned opt;
390 size_t n_max_chars;
391#if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM
392 xlist_t* (*read_args)(xlist_t*, const char*, size_t, char*) = process_stdin;
393#else
394#define read_args process_stdin
395#endif
396
397 opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &eof_str);
398
399 if (opt & OPT_ZEROTERM)
400 USE_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin);
401
402 argv += optind;
403 argc -= optind;
404 if (!argc) {
405 /* default behavior is to echo all the filenames */
406 *argv = (char*)"echo";
407 argc++;
408 }
409
410 orig_arg_max = ARG_MAX;
411 if (orig_arg_max == -1)
412 orig_arg_max = LONG_MAX;
413 orig_arg_max -= 2048; /* POSIX.2 requires subtracting 2048 */
414
415 if (opt & OPT_UPTO_SIZE) {
416 n_max_chars = xatoul_range(max_chars, 1, orig_arg_max);
417 for (i = 0; i < argc; i++) {
418 n_chars += strlen(*argv) + 1;
419 }
420 if (n_max_chars < n_chars) {
421 bb_error_msg_and_die("cannot fit single argument within argument list size limit");
422 }
423 n_max_chars -= n_chars;
424 } else {
425 /* Sanity check for systems with huge ARG_MAX defines (e.g., Suns which
426 have it at 1 meg). Things will work fine with a large ARG_MAX but it
427 will probably hurt the system more than it needs to; an array of this
428 size is allocated. */
429 if (orig_arg_max > 20 * 1024)
430 orig_arg_max = 20 * 1024;
431 n_max_chars = orig_arg_max;
432 }
433 max_chars = xmalloc(n_max_chars);
434
435 if (opt & OPT_UPTO_NUMBER) {
436 n_max_arg = xatoul_range(max_args, 1, INT_MAX);
437 } else {
438 n_max_arg = n_max_chars;
439 }
440
441 while ((list = read_args(list, eof_str, n_max_chars, max_chars)) != NULL ||
442 !(opt & OPT_NO_EMPTY))
443 {
444 opt |= OPT_NO_EMPTY;
445 n = 0;
446 n_chars = 0;
447#if ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT
448 for (cur = list; cur;) {
449 n_chars += cur->length;
450 n++;
451 cur = cur->link;
452 if (n_chars > n_max_chars || (n == n_max_arg && cur)) {
453 if (opt & OPT_TERMINATE)
454 bb_error_msg_and_die("argument list too long");
455 break;
456 }
457 }
458#else
459 for (cur = list; cur; cur = cur->link) {
460 n_chars += cur->length;
461 n++;
462 if (n_chars > n_max_chars || n == n_max_arg) {
463 break;
464 }
465 }
466#endif /* FEATURE_XARGS_SUPPORT_TERMOPT */
467
468 /* allocate pointers for execvp:
469 argc*arg, n*arg from stdin, NULL */
470 args = xzalloc((n + argc + 1) * sizeof(char *));
471
472 /* store the command to be executed
473 (taken from the command line) */
474 for (i = 0; i < argc; i++)
475 args[i] = argv[i];
476 /* (taken from stdin) */
477 for (cur = list; n; cur = cur->link) {
478 args[i++] = cur->xstr;
479 n--;
480 }
481
482 if (opt & (OPT_INTERACTIVE | OPT_VERBOSE)) {
483 for (i = 0; args[i]; i++) {
484 if (i)
485 fputc(' ', stderr);
486 fputs(args[i], stderr);
487 }
488 if (!(opt & OPT_INTERACTIVE))
489 fputc('\n', stderr);
490 }
491 if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) {
492 child_error = xargs_exec(args);
493 }
494
495 /* clean up */
496 for (i = argc; args[i]; i++) {
497 cur = list;
498 list = list->link;
499 free(cur);
500 }
501 free(args);
502 if (child_error > 0 && child_error != 123) {
503 break;
504 }
505 }
506 if (ENABLE_FEATURE_CLEAN_UP)
507 free(max_chars);
508 return child_error;
509}
510
511
512#ifdef TEST
513
514const char *applet_name = "debug stuff usage";
515
516void bb_show_usage(void)
517{
518 fprintf(stderr, "Usage: %s [-p] [-r] [-t] -[x] [-n max_arg] [-s max_chars]\n",
519 applet_name);
520 exit(1);
521}
522
523int main(int argc, char **argv)
524{
525 return xargs_main(argc, argv);
526}
527#endif /* TEST */
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