Contents of /tags/mkinitrd-6_2_2/busybox/findutils/xargs.c
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Sun May 30 12:33:03 2010 UTC (14 years, 3 months ago) by niro
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Sun May 30 12:33:03 2010 UTC (14 years, 3 months ago) by niro
File MIME type: text/plain
File size: 12993 byte(s)
tagged 'mkinitrd-6_2_2'
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 | */ |
54 | static int xargs_exec(char **args) |
55 | { |
56 | int status; |
57 | |
58 | status = spawn_and_wait(args); |
59 | if (status < 0) { |
60 | bb_simple_perror_msg(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 | |
85 | typedef struct xlist_t { |
86 | struct xlist_t *link; |
87 | size_t length; |
88 | char xstr[1]; |
89 | } xlist_t; |
90 | |
91 | static 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 |
98 | static 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 */ |
202 | static 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 ((size_t)(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. */ |
275 | static int xargs_ask_confirmation(void) |
276 | { |
277 | FILE *tty_stream; |
278 | int c, savec; |
279 | |
280 | tty_stream = xfopen_for_read(CURRENT_TTY); |
281 | fputs(" ?...", stderr); |
282 | fflush_all(); |
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 |
294 | static xlist_t *process0_stdin(xlist_t *list_arg, |
295 | const char *eof_str UNUSED_PARAM, 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 */ |
352 | enum { |
353 | OPTBIT_VERBOSE = 0, |
354 | OPTBIT_NO_EMPTY, |
355 | OPTBIT_UPTO_NUMBER, |
356 | OPTBIT_UPTO_SIZE, |
357 | OPTBIT_EOF_STRING, |
358 | OPTBIT_EOF_STRING1, |
359 | IF_FEATURE_XARGS_SUPPORT_CONFIRMATION(OPTBIT_INTERACTIVE,) |
360 | IF_FEATURE_XARGS_SUPPORT_TERMOPT( OPTBIT_TERMINATE ,) |
361 | IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( OPTBIT_ZEROTERM ,) |
362 | |
363 | OPT_VERBOSE = 1 << OPTBIT_VERBOSE , |
364 | OPT_NO_EMPTY = 1 << OPTBIT_NO_EMPTY , |
365 | OPT_UPTO_NUMBER = 1 << OPTBIT_UPTO_NUMBER, |
366 | OPT_UPTO_SIZE = 1 << OPTBIT_UPTO_SIZE , |
367 | OPT_EOF_STRING = 1 << OPTBIT_EOF_STRING , /* GNU: -e[<param>] */ |
368 | OPT_EOF_STRING1 = 1 << OPTBIT_EOF_STRING1, /* SUS: -E<param> */ |
369 | OPT_INTERACTIVE = IF_FEATURE_XARGS_SUPPORT_CONFIRMATION((1 << OPTBIT_INTERACTIVE)) + 0, |
370 | OPT_TERMINATE = IF_FEATURE_XARGS_SUPPORT_TERMOPT( (1 << OPTBIT_TERMINATE )) + 0, |
371 | OPT_ZEROTERM = IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( (1 << OPTBIT_ZEROTERM )) + 0, |
372 | }; |
373 | #define OPTION_STR "+trn:s:e::E:" \ |
374 | IF_FEATURE_XARGS_SUPPORT_CONFIRMATION("p") \ |
375 | IF_FEATURE_XARGS_SUPPORT_TERMOPT( "x") \ |
376 | IF_FEATURE_XARGS_SUPPORT_ZERO_TERM( "0") |
377 | |
378 | int xargs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
379 | int xargs_main(int argc, char **argv) |
380 | { |
381 | char **args; |
382 | int i, n; |
383 | xlist_t *list = NULL; |
384 | xlist_t *cur; |
385 | int child_error = 0; |
386 | char *max_args, *max_chars; |
387 | int n_max_arg; |
388 | size_t n_chars = 0; |
389 | long orig_arg_max; |
390 | const char *eof_str = NULL; |
391 | unsigned opt; |
392 | size_t n_max_chars; |
393 | #if ENABLE_FEATURE_XARGS_SUPPORT_ZERO_TERM |
394 | xlist_t* (*read_args)(xlist_t*, const char*, size_t, char*) = process_stdin; |
395 | #else |
396 | #define read_args process_stdin |
397 | #endif |
398 | |
399 | opt = getopt32(argv, OPTION_STR, &max_args, &max_chars, &eof_str, &eof_str); |
400 | |
401 | /* -E ""? You may wonder why not just omit -E? |
402 | * This is used for portability: |
403 | * old xargs was using "_" as default for -E / -e */ |
404 | if ((opt & OPT_EOF_STRING1) && eof_str[0] == '\0') |
405 | eof_str = NULL; |
406 | |
407 | if (opt & OPT_ZEROTERM) |
408 | IF_FEATURE_XARGS_SUPPORT_ZERO_TERM(read_args = process0_stdin); |
409 | |
410 | argv += optind; |
411 | argc -= optind; |
412 | if (!argc) { |
413 | /* default behavior is to echo all the filenames */ |
414 | *argv = (char*)"echo"; |
415 | argc++; |
416 | } |
417 | |
418 | orig_arg_max = ARG_MAX; |
419 | if (orig_arg_max == -1) |
420 | orig_arg_max = LONG_MAX; |
421 | orig_arg_max -= 2048; /* POSIX.2 requires subtracting 2048 */ |
422 | |
423 | if (opt & OPT_UPTO_SIZE) { |
424 | n_max_chars = xatoul_range(max_chars, 1, orig_arg_max); |
425 | for (i = 0; i < argc; i++) { |
426 | n_chars += strlen(*argv) + 1; |
427 | } |
428 | if (n_max_chars < n_chars) { |
429 | bb_error_msg_and_die("can't fit single argument within argument list size limit"); |
430 | } |
431 | n_max_chars -= n_chars; |
432 | } else { |
433 | /* Sanity check for systems with huge ARG_MAX defines (e.g., Suns which |
434 | have it at 1 meg). Things will work fine with a large ARG_MAX but it |
435 | will probably hurt the system more than it needs to; an array of this |
436 | size is allocated. */ |
437 | if (orig_arg_max > 20 * 1024) |
438 | orig_arg_max = 20 * 1024; |
439 | n_max_chars = orig_arg_max; |
440 | } |
441 | max_chars = xmalloc(n_max_chars); |
442 | |
443 | if (opt & OPT_UPTO_NUMBER) { |
444 | n_max_arg = xatoul_range(max_args, 1, INT_MAX); |
445 | } else { |
446 | n_max_arg = n_max_chars; |
447 | } |
448 | |
449 | while ((list = read_args(list, eof_str, n_max_chars, max_chars)) != NULL || |
450 | !(opt & OPT_NO_EMPTY)) |
451 | { |
452 | opt |= OPT_NO_EMPTY; |
453 | n = 0; |
454 | n_chars = 0; |
455 | #if ENABLE_FEATURE_XARGS_SUPPORT_TERMOPT |
456 | for (cur = list; cur;) { |
457 | n_chars += cur->length; |
458 | n++; |
459 | cur = cur->link; |
460 | if (n_chars > n_max_chars || (n == n_max_arg && cur)) { |
461 | if (opt & OPT_TERMINATE) |
462 | bb_error_msg_and_die("argument list too long"); |
463 | break; |
464 | } |
465 | } |
466 | #else |
467 | for (cur = list; cur; cur = cur->link) { |
468 | n_chars += cur->length; |
469 | n++; |
470 | if (n_chars > n_max_chars || n == n_max_arg) { |
471 | break; |
472 | } |
473 | } |
474 | #endif /* FEATURE_XARGS_SUPPORT_TERMOPT */ |
475 | |
476 | /* allocate pointers for execvp: |
477 | argc*arg, n*arg from stdin, NULL */ |
478 | args = xzalloc((n + argc + 1) * sizeof(char *)); |
479 | |
480 | /* store the command to be executed |
481 | (taken from the command line) */ |
482 | for (i = 0; i < argc; i++) |
483 | args[i] = argv[i]; |
484 | /* (taken from stdin) */ |
485 | for (cur = list; n; cur = cur->link) { |
486 | args[i++] = cur->xstr; |
487 | n--; |
488 | } |
489 | |
490 | if (opt & (OPT_INTERACTIVE | OPT_VERBOSE)) { |
491 | for (i = 0; args[i]; i++) { |
492 | if (i) |
493 | fputc(' ', stderr); |
494 | fputs(args[i], stderr); |
495 | } |
496 | if (!(opt & OPT_INTERACTIVE)) |
497 | fputc('\n', stderr); |
498 | } |
499 | if (!(opt & OPT_INTERACTIVE) || xargs_ask_confirmation()) { |
500 | child_error = xargs_exec(args); |
501 | } |
502 | |
503 | /* clean up */ |
504 | for (i = argc; args[i]; i++) { |
505 | cur = list; |
506 | list = list->link; |
507 | free(cur); |
508 | } |
509 | free(args); |
510 | if (child_error > 0 && child_error != 123) { |
511 | break; |
512 | } |
513 | } /* while */ |
514 | if (ENABLE_FEATURE_CLEAN_UP) |
515 | free(max_chars); |
516 | return child_error; |
517 | } |
518 | |
519 | |
520 | #ifdef TEST |
521 | |
522 | const char *applet_name = "debug stuff usage"; |
523 | |
524 | void bb_show_usage(void) |
525 | { |
526 | fprintf(stderr, "Usage: %s [-p] [-r] [-t] -[x] [-n max_arg] [-s max_chars]\n", |
527 | applet_name); |
528 | exit(EXIT_FAILURE); |
529 | } |
530 | |
531 | int main(int argc, char **argv) |
532 | { |
533 | return xargs_main(argc, argv); |
534 | } |
535 | #endif /* TEST */ |