grep: be GNU compatible with -f EMPTY_FILE
[platform/upstream/busybox.git] / findutils / grep.c
1 /* vi: set sw=4 ts=4: */
2 /*
3  * Mini grep implementation for busybox using libc regex.
4  *
5  * Copyright (C) 1999,2000,2001 by Lineo, inc. and Mark Whitley
6  * Copyright (C) 1999,2000,2001 by Mark Whitley <markw@codepoet.org>
7  *
8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
9  */
10 /* BB_AUDIT SUSv3 defects - unsupported option -x "match whole line only". */
11 /* BB_AUDIT GNU defects - always acts as -a.  */
12 /* http://www.opengroup.org/onlinepubs/007904975/utilities/grep.html */
13 /*
14  * 2004,2006 (C) Vladimir Oleynik <dzo@simtreas.ru> -
15  * correction "-e pattern1 -e pattern2" logic and more optimizations.
16  * precompiled regex
17  *
18  * (C) 2006 Jac Goudsmit added -o option
19  */
20
21 //applet:IF_GREP(APPLET(grep, BB_DIR_BIN, BB_SUID_DROP))
22 //applet:IF_FEATURE_GREP_EGREP_ALIAS(APPLET_ODDNAME(egrep, grep, BB_DIR_BIN, BB_SUID_DROP, egrep))
23 //applet:IF_FEATURE_GREP_FGREP_ALIAS(APPLET_ODDNAME(fgrep, grep, BB_DIR_BIN, BB_SUID_DROP, fgrep))
24
25 //kbuild:lib-$(CONFIG_GREP) += grep.o
26
27 //config:config GREP
28 //config:       bool "grep"
29 //config:       default y
30 //config:       help
31 //config:         grep is used to search files for a specified pattern.
32 //config:
33 //config:config FEATURE_GREP_EGREP_ALIAS
34 //config:       bool "Enable extended regular expressions (egrep & grep -E)"
35 //config:       default y
36 //config:       depends on GREP
37 //config:       help
38 //config:         Enabled support for extended regular expressions. Extended
39 //config:         regular expressions allow for alternation (foo|bar), grouping,
40 //config:         and various repetition operators.
41 //config:
42 //config:config FEATURE_GREP_FGREP_ALIAS
43 //config:       bool "Alias fgrep to grep -F"
44 //config:       default y
45 //config:       depends on GREP
46 //config:       help
47 //config:         fgrep sees the search pattern as a normal string rather than
48 //config:         regular expressions.
49 //config:         grep -F always works, this just creates the fgrep alias.
50 //config:
51 //config:config FEATURE_GREP_CONTEXT
52 //config:       bool "Enable before and after context flags (-A, -B and -C)"
53 //config:       default y
54 //config:       depends on GREP
55 //config:       help
56 //config:         Print the specified number of leading (-B) and/or trailing (-A)
57 //config:         context surrounding our matching lines.
58 //config:         Print the specified number of context lines (-C).
59
60 #include "libbb.h"
61 #include "xregex.h"
62
63
64 /* options */
65 //usage:#define grep_trivial_usage
66 //usage:       "[-HhnlLoqvsriw"
67 //usage:       "F"
68 //usage:        IF_FEATURE_GREP_EGREP_ALIAS("E")
69 //usage:        IF_EXTRA_COMPAT("z")
70 //usage:       "] [-m N] "
71 //usage:        IF_FEATURE_GREP_CONTEXT("[-A/B/C N] ")
72 //usage:       "PATTERN/-e PATTERN.../-f FILE [FILE]..."
73 //usage:#define grep_full_usage "\n\n"
74 //usage:       "Search for PATTERN in FILEs (or stdin)\n"
75 //usage:     "\n        -H      Add 'filename:' prefix"
76 //usage:     "\n        -h      Do not add 'filename:' prefix"
77 //usage:     "\n        -n      Add 'line_no:' prefix"
78 //usage:     "\n        -l      Show only names of files that match"
79 //usage:     "\n        -L      Show only names of files that don't match"
80 //usage:     "\n        -c      Show only count of matching lines"
81 //usage:     "\n        -o      Show only the matching part of line"
82 //usage:     "\n        -q      Quiet. Return 0 if PATTERN is found, 1 otherwise"
83 //usage:     "\n        -v      Select non-matching lines"
84 //usage:     "\n        -s      Suppress open and read errors"
85 //usage:     "\n        -r      Recurse"
86 //usage:     "\n        -i      Ignore case"
87 //usage:     "\n        -w      Match whole words only"
88 //usage:     "\n        -F      PATTERN is a literal (not regexp)"
89 //usage:        IF_FEATURE_GREP_EGREP_ALIAS(
90 //usage:     "\n        -E      PATTERN is an extended regexp"
91 //usage:        )
92 //usage:        IF_EXTRA_COMPAT(
93 //usage:     "\n        -z      Input is NUL terminated"
94 //usage:        )
95 //usage:     "\n        -m N    Match up to N times per file"
96 //usage:        IF_FEATURE_GREP_CONTEXT(
97 //usage:     "\n        -A N    Print N lines of trailing context"
98 //usage:     "\n        -B N    Print N lines of leading context"
99 //usage:     "\n        -C N    Same as '-A N -B N'"
100 //usage:        )
101 //usage:     "\n        -e PTRN Pattern to match"
102 //usage:     "\n        -f FILE Read pattern from file"
103 //usage:
104 //usage:#define grep_example_usage
105 //usage:       "$ grep root /etc/passwd\n"
106 //usage:       "root:x:0:0:root:/root:/bin/bash\n"
107 //usage:       "$ grep ^[rR]oo. /etc/passwd\n"
108 //usage:       "root:x:0:0:root:/root:/bin/bash\n"
109 //usage:
110 //usage:#define egrep_trivial_usage NOUSAGE_STR
111 //usage:#define egrep_full_usage ""
112 //usage:#define fgrep_trivial_usage NOUSAGE_STR
113 //usage:#define fgrep_full_usage ""
114
115 #define OPTSTR_GREP \
116         "lnqvscFiHhe:f:Lorm:w" \
117         IF_FEATURE_GREP_CONTEXT("A:B:C:") \
118         IF_FEATURE_GREP_EGREP_ALIAS("E") \
119         IF_EXTRA_COMPAT("z") \
120         "aI"
121 /* ignored: -a "assume all files to be text" */
122 /* ignored: -I "assume binary files have no matches" */
123 enum {
124         OPTBIT_l, /* list matched file names only */
125         OPTBIT_n, /* print line# */
126         OPTBIT_q, /* quiet - exit(EXIT_SUCCESS) of first match */
127         OPTBIT_v, /* invert the match, to select non-matching lines */
128         OPTBIT_s, /* suppress errors about file open errors */
129         OPTBIT_c, /* count matches per file (suppresses normal output) */
130         OPTBIT_F, /* literal match */
131         OPTBIT_i, /* case-insensitive */
132         OPTBIT_H, /* force filename display */
133         OPTBIT_h, /* inhibit filename display */
134         OPTBIT_e, /* -e PATTERN */
135         OPTBIT_f, /* -f FILE_WITH_PATTERNS */
136         OPTBIT_L, /* list unmatched file names only */
137         OPTBIT_o, /* show only matching parts of lines */
138         OPTBIT_r, /* recurse dirs */
139         OPTBIT_m, /* -m MAX_MATCHES */
140         OPTBIT_w, /* -w whole word match */
141         IF_FEATURE_GREP_CONTEXT(    OPTBIT_A ,) /* -A NUM: after-match context */
142         IF_FEATURE_GREP_CONTEXT(    OPTBIT_B ,) /* -B NUM: before-match context */
143         IF_FEATURE_GREP_CONTEXT(    OPTBIT_C ,) /* -C NUM: -A and -B combined */
144         IF_FEATURE_GREP_EGREP_ALIAS(OPTBIT_E ,) /* extended regexp */
145         IF_EXTRA_COMPAT(            OPTBIT_z ,) /* input is NUL terminated */
146         OPT_l = 1 << OPTBIT_l,
147         OPT_n = 1 << OPTBIT_n,
148         OPT_q = 1 << OPTBIT_q,
149         OPT_v = 1 << OPTBIT_v,
150         OPT_s = 1 << OPTBIT_s,
151         OPT_c = 1 << OPTBIT_c,
152         OPT_F = 1 << OPTBIT_F,
153         OPT_i = 1 << OPTBIT_i,
154         OPT_H = 1 << OPTBIT_H,
155         OPT_h = 1 << OPTBIT_h,
156         OPT_e = 1 << OPTBIT_e,
157         OPT_f = 1 << OPTBIT_f,
158         OPT_L = 1 << OPTBIT_L,
159         OPT_o = 1 << OPTBIT_o,
160         OPT_r = 1 << OPTBIT_r,
161         OPT_m = 1 << OPTBIT_m,
162         OPT_w = 1 << OPTBIT_w,
163         OPT_A = IF_FEATURE_GREP_CONTEXT(    (1 << OPTBIT_A)) + 0,
164         OPT_B = IF_FEATURE_GREP_CONTEXT(    (1 << OPTBIT_B)) + 0,
165         OPT_C = IF_FEATURE_GREP_CONTEXT(    (1 << OPTBIT_C)) + 0,
166         OPT_E = IF_FEATURE_GREP_EGREP_ALIAS((1 << OPTBIT_E)) + 0,
167         OPT_z = IF_EXTRA_COMPAT(            (1 << OPTBIT_z)) + 0,
168 };
169
170 #define PRINT_FILES_WITH_MATCHES    (option_mask32 & OPT_l)
171 #define PRINT_LINE_NUM              (option_mask32 & OPT_n)
172 #define BE_QUIET                    (option_mask32 & OPT_q)
173 #define SUPPRESS_ERR_MSGS           (option_mask32 & OPT_s)
174 #define PRINT_MATCH_COUNTS          (option_mask32 & OPT_c)
175 #define FGREP_FLAG                  (option_mask32 & OPT_F)
176 #define PRINT_FILES_WITHOUT_MATCHES (option_mask32 & OPT_L)
177 #define NUL_DELIMITED               (option_mask32 & OPT_z)
178
179 struct globals {
180         int max_matches;
181 #if !ENABLE_EXTRA_COMPAT
182         int reflags;
183 #else
184         RE_TRANSLATE_TYPE case_fold; /* RE_TRANSLATE_TYPE is [[un]signed] char* */
185 #endif
186         smalluint invert_search;
187         smalluint print_filename;
188         smalluint open_errors;
189 #if ENABLE_FEATURE_GREP_CONTEXT
190         smalluint did_print_line;
191         int lines_before;
192         int lines_after;
193         char **before_buf;
194         IF_EXTRA_COMPAT(size_t *before_buf_size;)
195         int last_line_printed;
196 #endif
197         /* globals used internally */
198         llist_t *pattern_head;   /* growable list of patterns to match */
199         const char *cur_file;    /* the current file we are reading */
200 } FIX_ALIASING;
201 #define G (*(struct globals*)&bb_common_bufsiz1)
202 #define INIT_G() do { \
203         struct G_sizecheck { \
204                 char G_sizecheck[sizeof(G) > COMMON_BUFSIZE ? -1 : 1]; \
205         }; \
206 } while (0)
207 #define max_matches       (G.max_matches         )
208 #if !ENABLE_EXTRA_COMPAT
209 # define reflags          (G.reflags             )
210 #else
211 # define case_fold        (G.case_fold           )
212 /* http://www.delorie.com/gnu/docs/regex/regex_46.html */
213 # define reflags           re_syntax_options
214 # undef REG_NOSUB
215 # undef REG_EXTENDED
216 # undef REG_ICASE
217 # define REG_NOSUB    bug:is:here /* should not be used */
218 /* Just RE_SYNTAX_EGREP is not enough, need to enable {n[,[m]]} too */
219 # define REG_EXTENDED (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES)
220 # define REG_ICASE    bug:is:here /* should not be used */
221 #endif
222 #define invert_search     (G.invert_search       )
223 #define print_filename    (G.print_filename      )
224 #define open_errors       (G.open_errors         )
225 #define did_print_line    (G.did_print_line      )
226 #define lines_before      (G.lines_before        )
227 #define lines_after       (G.lines_after         )
228 #define before_buf        (G.before_buf          )
229 #define before_buf_size   (G.before_buf_size     )
230 #define last_line_printed (G.last_line_printed   )
231 #define pattern_head      (G.pattern_head        )
232 #define cur_file          (G.cur_file            )
233
234
235 typedef struct grep_list_data_t {
236         char *pattern;
237 /* for GNU regex, matched_range must be persistent across grep_file() calls */
238 #if !ENABLE_EXTRA_COMPAT
239         regex_t compiled_regex;
240         regmatch_t matched_range;
241 #else
242         struct re_pattern_buffer compiled_regex;
243         struct re_registers matched_range;
244 #endif
245 #define ALLOCATED 1
246 #define COMPILED 2
247         int flg_mem_alocated_compiled;
248 } grep_list_data_t;
249
250 #if !ENABLE_EXTRA_COMPAT
251 #define print_line(line, line_len, linenum, decoration) \
252         print_line(line, linenum, decoration)
253 #endif
254 static void print_line(const char *line, size_t line_len, int linenum, char decoration)
255 {
256 #if ENABLE_FEATURE_GREP_CONTEXT
257         /* Happens when we go to next file, immediately hit match
258          * and try to print prev context... from prev file! Don't do it */
259         if (linenum < 1)
260                 return;
261         /* possibly print the little '--' separator */
262         if ((lines_before || lines_after) && did_print_line
263          && last_line_printed != linenum - 1
264         ) {
265                 puts("--");
266         }
267         /* guard against printing "--" before first line of first file */
268         did_print_line = 1;
269         last_line_printed = linenum;
270 #endif
271         if (print_filename)
272                 printf("%s%c", cur_file, decoration);
273         if (PRINT_LINE_NUM)
274                 printf("%i%c", linenum, decoration);
275         /* Emulate weird GNU grep behavior with -ov */
276         if ((option_mask32 & (OPT_v|OPT_o)) != (OPT_v|OPT_o)) {
277 #if !ENABLE_EXTRA_COMPAT
278                 puts(line);
279 #else
280                 fwrite(line, 1, line_len, stdout);
281                 putchar(NUL_DELIMITED ? '\0' : '\n');
282 #endif
283         }
284 }
285
286 #if ENABLE_EXTRA_COMPAT
287 /* Unlike getline, this one removes trailing '\n' */
288 static ssize_t FAST_FUNC bb_getline(char **line_ptr, size_t *line_alloc_len, FILE *file)
289 {
290         ssize_t res_sz;
291         char *line;
292         int delim = (NUL_DELIMITED ? '\0' : '\n');
293
294         res_sz = getdelim(line_ptr, line_alloc_len, delim, file);
295         line = *line_ptr;
296
297         if (res_sz > 0) {
298                 if (line[res_sz - 1] == delim)
299                         line[--res_sz] = '\0';
300         } else {
301                 free(line); /* uclibc allocates a buffer even on EOF. WTF? */
302         }
303         return res_sz;
304 }
305 #endif
306
307 static int grep_file(FILE *file)
308 {
309         smalluint found;
310         int linenum = 0;
311         int nmatches = 0;
312 #if !ENABLE_EXTRA_COMPAT
313         char *line;
314 #else
315         char *line = NULL;
316         ssize_t line_len;
317         size_t line_alloc_len;
318 # define rm_so start[0]
319 # define rm_eo end[0]
320 #endif
321 #if ENABLE_FEATURE_GREP_CONTEXT
322         int print_n_lines_after = 0;
323         int curpos = 0; /* track where we are in the circular 'before' buffer */
324         int idx = 0; /* used for iteration through the circular buffer */
325 #else
326         enum { print_n_lines_after = 0 };
327 #endif
328
329         while (
330 #if !ENABLE_EXTRA_COMPAT
331                 (line = xmalloc_fgetline(file)) != NULL
332 #else
333                 (line_len = bb_getline(&line, &line_alloc_len, file)) >= 0
334 #endif
335         ) {
336                 llist_t *pattern_ptr = pattern_head;
337                 grep_list_data_t *gl = gl; /* for gcc */
338
339                 linenum++;
340                 found = 0;
341                 while (pattern_ptr) {
342                         gl = (grep_list_data_t *)pattern_ptr->data;
343                         if (FGREP_FLAG) {
344                                 found |= (((option_mask32 & OPT_i)
345                                         ? strcasestr(line, gl->pattern)
346                                         : strstr(line, gl->pattern)
347                                         ) != NULL);
348                         } else {
349                                 if (!(gl->flg_mem_alocated_compiled & COMPILED)) {
350                                         gl->flg_mem_alocated_compiled |= COMPILED;
351 #if !ENABLE_EXTRA_COMPAT
352                                         xregcomp(&gl->compiled_regex, gl->pattern, reflags);
353 #else
354                                         memset(&gl->compiled_regex, 0, sizeof(gl->compiled_regex));
355                                         gl->compiled_regex.translate = case_fold; /* for -i */
356                                         if (re_compile_pattern(gl->pattern, strlen(gl->pattern), &gl->compiled_regex))
357                                                 bb_error_msg_and_die("bad regex '%s'", gl->pattern);
358 #endif
359                                 }
360 #if !ENABLE_EXTRA_COMPAT
361                                 gl->matched_range.rm_so = 0;
362                                 gl->matched_range.rm_eo = 0;
363 #endif
364                                 if (
365 #if !ENABLE_EXTRA_COMPAT
366                                         regexec(&gl->compiled_regex, line, 1, &gl->matched_range, 0) == 0
367 #else
368                                         re_search(&gl->compiled_regex, line, line_len,
369                                                         /*start:*/ 0, /*range:*/ line_len,
370                                                         &gl->matched_range) >= 0
371 #endif
372                                 ) {
373                                         if (!(option_mask32 & OPT_w))
374                                                 found = 1;
375                                         else {
376                                                 char c = ' ';
377                                                 if (gl->matched_range.rm_so)
378                                                         c = line[gl->matched_range.rm_so - 1];
379                                                 if (!isalnum(c) && c != '_') {
380                                                         c = line[gl->matched_range.rm_eo];
381                                                         if (!c || (!isalnum(c) && c != '_'))
382                                                                 found = 1;
383                                                 }
384                                         }
385                                 }
386                         }
387                         /* If it's non-inverted search, we can stop
388                          * at first match */
389                         if (found && !invert_search)
390                                 goto do_found;
391                         pattern_ptr = pattern_ptr->link;
392                 } /* while (pattern_ptr) */
393
394                 if (found ^ invert_search) {
395  do_found:
396                         /* keep track of matches */
397                         nmatches++;
398
399                         /* quiet/print (non)matching file names only? */
400                         if (option_mask32 & (OPT_q|OPT_l|OPT_L)) {
401                                 free(line); /* we don't need line anymore */
402                                 if (BE_QUIET) {
403                                         /* manpage says about -q:
404                                          * "exit immediately with zero status
405                                          * if any match is found,
406                                          * even if errors were detected" */
407                                         exit(EXIT_SUCCESS);
408                                 }
409                                 /* if we're just printing filenames, we stop after the first match */
410                                 if (PRINT_FILES_WITH_MATCHES) {
411                                         puts(cur_file);
412                                         /* fall through to "return 1" */
413                                 }
414                                 /* OPT_L aka PRINT_FILES_WITHOUT_MATCHES: return early */
415                                 return 1; /* one match */
416                         }
417
418 #if ENABLE_FEATURE_GREP_CONTEXT
419                         /* Were we printing context and saw next (unwanted) match? */
420                         if ((option_mask32 & OPT_m) && nmatches > max_matches)
421                                 break;
422 #endif
423
424                         /* print the matched line */
425                         if (PRINT_MATCH_COUNTS == 0) {
426 #if ENABLE_FEATURE_GREP_CONTEXT
427                                 int prevpos = (curpos == 0) ? lines_before - 1 : curpos - 1;
428
429                                 /* if we were told to print 'before' lines and there is at least
430                                  * one line in the circular buffer, print them */
431                                 if (lines_before && before_buf[prevpos] != NULL) {
432                                         int first_buf_entry_line_num = linenum - lines_before;
433
434                                         /* advance to the first entry in the circular buffer, and
435                                          * figure out the line number is of the first line in the
436                                          * buffer */
437                                         idx = curpos;
438                                         while (before_buf[idx] == NULL) {
439                                                 idx = (idx + 1) % lines_before;
440                                                 first_buf_entry_line_num++;
441                                         }
442
443                                         /* now print each line in the buffer, clearing them as we go */
444                                         while (before_buf[idx] != NULL) {
445                                                 print_line(before_buf[idx], before_buf_size[idx], first_buf_entry_line_num, '-');
446                                                 free(before_buf[idx]);
447                                                 before_buf[idx] = NULL;
448                                                 idx = (idx + 1) % lines_before;
449                                                 first_buf_entry_line_num++;
450                                         }
451                                 }
452
453                                 /* make a note that we need to print 'after' lines */
454                                 print_n_lines_after = lines_after;
455 #endif
456                                 if (option_mask32 & OPT_o) {
457                                         if (FGREP_FLAG) {
458                                                 /* -Fo just prints the pattern
459                                                  * (unless -v: -Fov doesnt print anything at all) */
460                                                 if (found)
461                                                         print_line(gl->pattern, strlen(gl->pattern), linenum, ':');
462                                         } else while (1) {
463                                                 unsigned start = gl->matched_range.rm_so;
464                                                 unsigned end = gl->matched_range.rm_eo;
465                                                 unsigned len = end - start;
466                                                 char old = line[end];
467                                                 line[end] = '\0';
468                                                 /* Empty match is not printed: try "echo test | grep -o ''" */
469                                                 if (len != 0)
470                                                         print_line(line + start, len, linenum, ':');
471                                                 if (old == '\0')
472                                                         break;
473                                                 line[end] = old;
474                                                 if (len == 0)
475                                                         end++;
476 #if !ENABLE_EXTRA_COMPAT
477                                                 if (regexec(&gl->compiled_regex, line + end,
478                                                                 1, &gl->matched_range, REG_NOTBOL) != 0)
479                                                         break;
480                                                 gl->matched_range.rm_so += end;
481                                                 gl->matched_range.rm_eo += end;
482 #else
483                                                 if (re_search(&gl->compiled_regex, line, line_len,
484                                                                 end, line_len - end,
485                                                                 &gl->matched_range) < 0)
486                                                         break;
487 #endif
488                                         }
489                                 } else {
490                                         print_line(line, line_len, linenum, ':');
491                                 }
492                         }
493                 }
494 #if ENABLE_FEATURE_GREP_CONTEXT
495                 else { /* no match */
496                         /* if we need to print some context lines after the last match, do so */
497                         if (print_n_lines_after) {
498                                 print_line(line, strlen(line), linenum, '-');
499                                 print_n_lines_after--;
500                         } else if (lines_before) {
501                                 /* Add the line to the circular 'before' buffer */
502                                 free(before_buf[curpos]);
503                                 before_buf[curpos] = line;
504                                 IF_EXTRA_COMPAT(before_buf_size[curpos] = line_len;)
505                                 curpos = (curpos + 1) % lines_before;
506                                 /* avoid free(line) - we took the line */
507                                 line = NULL;
508                         }
509                 }
510
511 #endif /* ENABLE_FEATURE_GREP_CONTEXT */
512 #if !ENABLE_EXTRA_COMPAT
513                 free(line);
514 #endif
515                 /* Did we print all context after last requested match? */
516                 if ((option_mask32 & OPT_m)
517                  && !print_n_lines_after
518                  && nmatches == max_matches
519                 ) {
520                         break;
521                 }
522         } /* while (read line) */
523
524         /* special-case file post-processing for options where we don't print line
525          * matches, just filenames and possibly match counts */
526
527         /* grep -c: print [filename:]count, even if count is zero */
528         if (PRINT_MATCH_COUNTS) {
529                 if (print_filename)
530                         printf("%s:", cur_file);
531                 printf("%d\n", nmatches);
532         }
533
534         /* grep -L: print just the filename */
535         if (PRINT_FILES_WITHOUT_MATCHES) {
536                 /* nmatches is zero, no need to check it:
537                  * we return 1 early if we detected a match
538                  * and PRINT_FILES_WITHOUT_MATCHES is set */
539                 puts(cur_file);
540         }
541
542         return nmatches;
543 }
544
545 #if ENABLE_FEATURE_CLEAN_UP
546 #define new_grep_list_data(p, m) add_grep_list_data(p, m)
547 static char *add_grep_list_data(char *pattern, int flg_used_mem)
548 #else
549 #define new_grep_list_data(p, m) add_grep_list_data(p)
550 static char *add_grep_list_data(char *pattern)
551 #endif
552 {
553         grep_list_data_t *gl = xzalloc(sizeof(*gl));
554         gl->pattern = pattern;
555 #if ENABLE_FEATURE_CLEAN_UP
556         gl->flg_mem_alocated_compiled = flg_used_mem;
557 #else
558         /*gl->flg_mem_alocated_compiled = 0;*/
559 #endif
560         return (char *)gl;
561 }
562
563 static void load_regexes_from_file(llist_t *fopt)
564 {
565         while (fopt) {
566                 char *line;
567                 FILE *fp;
568                 llist_t *cur = fopt;
569                 char *ffile = cur->data;
570
571                 fopt = cur->link;
572                 free(cur);
573                 fp = xfopen_stdin(ffile);
574                 while ((line = xmalloc_fgetline(fp)) != NULL) {
575                         llist_add_to(&pattern_head,
576                                 new_grep_list_data(line, ALLOCATED));
577                 }
578                 fclose_if_not_stdin(fp);
579         }
580 }
581
582 static int FAST_FUNC file_action_grep(const char *filename,
583                         struct stat *statbuf UNUSED_PARAM,
584                         void* matched,
585                         int depth UNUSED_PARAM)
586 {
587         FILE *file = fopen_for_read(filename);
588         if (file == NULL) {
589                 if (!SUPPRESS_ERR_MSGS)
590                         bb_simple_perror_msg(filename);
591                 open_errors = 1;
592                 return 0;
593         }
594         cur_file = filename;
595         *(int*)matched += grep_file(file);
596         fclose(file);
597         return 1;
598 }
599
600 static int grep_dir(const char *dir)
601 {
602         int matched = 0;
603         recursive_action(dir,
604                 /* recurse=yes */ ACTION_RECURSE |
605                 /* followLinks=no */
606                 /* depthFirst=yes */ ACTION_DEPTHFIRST,
607                 /* fileAction= */ file_action_grep,
608                 /* dirAction= */ NULL,
609                 /* userData= */ &matched,
610                 /* depth= */ 0);
611         return matched;
612 }
613
614 int grep_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
615 int grep_main(int argc UNUSED_PARAM, char **argv)
616 {
617         FILE *file;
618         int matched;
619         llist_t *fopt = NULL;
620
621         /* do normal option parsing */
622 #if ENABLE_FEATURE_GREP_CONTEXT
623         int Copt, opts;
624
625         /* -H unsets -h; -C unsets -A,-B; -e,-f are lists;
626          * -m,-A,-B,-C have numeric param */
627         opt_complementary = "H-h:C-AB:e::f::m+:A+:B+:C+";
628         opts = getopt32(argv,
629                 OPTSTR_GREP,
630                 &pattern_head, &fopt, &max_matches,
631                 &lines_after, &lines_before, &Copt);
632
633         if (opts & OPT_C) {
634                 /* -C unsets prev -A and -B, but following -A or -B
635                    may override it */
636                 if (!(opts & OPT_A)) /* not overridden */
637                         lines_after = Copt;
638                 if (!(opts & OPT_B)) /* not overridden */
639                         lines_before = Copt;
640         }
641         /* sanity checks */
642         if (opts & (OPT_c|OPT_q|OPT_l|OPT_L)) {
643                 option_mask32 &= ~OPT_n;
644                 lines_before = 0;
645                 lines_after = 0;
646         } else if (lines_before > 0) {
647                 if (lines_before > INT_MAX / sizeof(long long))
648                         lines_before = INT_MAX / sizeof(long long);
649                 /* overflow in (lines_before * sizeof(x)) is prevented (above) */
650                 before_buf = xzalloc(lines_before * sizeof(before_buf[0]));
651                 IF_EXTRA_COMPAT(before_buf_size = xzalloc(lines_before * sizeof(before_buf_size[0]));)
652         }
653 #else
654         /* with auto sanity checks */
655         /* -H unsets -h; -c,-q or -l unset -n; -e,-f are lists; -m N */
656         opt_complementary = "H-h:c-n:q-n:l-n:e::f::m+";
657         getopt32(argv, OPTSTR_GREP,
658                 &pattern_head, &fopt, &max_matches);
659 #endif
660         invert_search = ((option_mask32 & OPT_v) != 0); /* 0 | 1 */
661
662         {       /* convert char **argv to grep_list_data_t */
663                 llist_t *cur;
664                 for (cur = pattern_head; cur; cur = cur->link)
665                         cur->data = new_grep_list_data(cur->data, 0);
666         }
667         if (option_mask32 & OPT_f) {
668                 load_regexes_from_file(fopt);
669                 if (!pattern_head) { /* -f EMPTY_FILE? */
670                         /* GNU grep treats it as "nothing matches" */
671                         llist_add_to(&pattern_head, new_grep_list_data((char*) "", 0));
672                         invert_search ^= 1;
673                 }
674         }
675
676         if (ENABLE_FEATURE_GREP_FGREP_ALIAS && applet_name[0] == 'f')
677                 option_mask32 |= OPT_F;
678
679 #if !ENABLE_EXTRA_COMPAT
680         if (!(option_mask32 & (OPT_o | OPT_w)))
681                 reflags = REG_NOSUB;
682 #endif
683
684         if (ENABLE_FEATURE_GREP_EGREP_ALIAS
685          && (applet_name[0] == 'e' || (option_mask32 & OPT_E))
686         ) {
687                 reflags |= REG_EXTENDED;
688         }
689 #if ENABLE_EXTRA_COMPAT
690         else {
691                 reflags = RE_SYNTAX_GREP;
692         }
693 #endif
694
695         if (option_mask32 & OPT_i) {
696 #if !ENABLE_EXTRA_COMPAT
697                 reflags |= REG_ICASE;
698 #else
699                 int i;
700                 case_fold = xmalloc(256);
701                 for (i = 0; i < 256; i++)
702                         case_fold[i] = (unsigned char)i;
703                 for (i = 'a'; i <= 'z'; i++)
704                         case_fold[i] = (unsigned char)(i - ('a' - 'A'));
705 #endif
706         }
707
708         argv += optind;
709
710         /* if we didn't get a pattern from -e and no command file was specified,
711          * first parameter should be the pattern. no pattern, no worky */
712         if (pattern_head == NULL) {
713                 char *pattern;
714                 if (*argv == NULL)
715                         bb_show_usage();
716                 pattern = new_grep_list_data(*argv++, 0);
717                 llist_add_to(&pattern_head, pattern);
718         }
719
720         /* argv[0..(argc-1)] should be names of file to grep through. If
721          * there is more than one file to grep, we will print the filenames. */
722         if (argv[0] && argv[1])
723                 print_filename = 1;
724         /* -H / -h of course override */
725         if (option_mask32 & OPT_H)
726                 print_filename = 1;
727         if (option_mask32 & OPT_h)
728                 print_filename = 0;
729
730         /* If no files were specified, or '-' was specified, take input from
731          * stdin. Otherwise, we grep through all the files specified. */
732         matched = 0;
733         do {
734                 cur_file = *argv;
735                 file = stdin;
736                 if (!cur_file || LONE_DASH(cur_file)) {
737                         cur_file = "(standard input)";
738                 } else {
739                         if (option_mask32 & OPT_r) {
740                                 struct stat st;
741                                 if (stat(cur_file, &st) == 0 && S_ISDIR(st.st_mode)) {
742                                         if (!(option_mask32 & OPT_h))
743                                                 print_filename = 1;
744                                         matched += grep_dir(cur_file);
745                                         goto grep_done;
746                                 }
747                         }
748                         /* else: fopen(dir) will succeed, but reading won't */
749                         file = fopen_for_read(cur_file);
750                         if (file == NULL) {
751                                 if (!SUPPRESS_ERR_MSGS)
752                                         bb_simple_perror_msg(cur_file);
753                                 open_errors = 1;
754                                 continue;
755                         }
756                 }
757                 matched += grep_file(file);
758                 fclose_if_not_stdin(file);
759  grep_done: ;
760         } while (*argv && *++argv);
761
762         /* destroy all the elments in the pattern list */
763         if (ENABLE_FEATURE_CLEAN_UP) {
764                 while (pattern_head) {
765                         llist_t *pattern_head_ptr = pattern_head;
766                         grep_list_data_t *gl = (grep_list_data_t *)pattern_head_ptr->data;
767
768                         pattern_head = pattern_head->link;
769                         if (gl->flg_mem_alocated_compiled & ALLOCATED)
770                                 free(gl->pattern);
771                         if (gl->flg_mem_alocated_compiled & COMPILED)
772                                 regfree(&gl->compiled_regex);
773                         free(gl);
774                         free(pattern_head_ptr);
775                 }
776         }
777         /* 0 = success, 1 = failed, 2 = error */
778         if (open_errors)
779                 return 2;
780         return !matched; /* invert return value: 0 = success, 1 = failed */
781 }