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 the GPL v2 or later, see the file LICENSE in this tarball.
   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 /*
  19  * (C) 2006 Jac Goudsmit added -o option
  20  */
  21
  22 #include "libbb.h"
  23 #include "xregex.h"
  24
  25 /* options */
  26 #define OPTSTR_GREP \
  27         "lnqvscFiHhe:f:Lorm:" \
  28         USE_FEATURE_GREP_CONTEXT("A:B:C:") \
  29         USE_FEATURE_GREP_EGREP_ALIAS("E") \
  30         USE_DESKTOP("w") \
  31         USE_EXTRA_COMPAT("z") \
  32         "aI"
  33
  34 /* ignored: -a "assume all files to be text" */
  35 /* ignored: -I "assume binary files have no matches" */
  36
  37 enum {
  38         OPTBIT_l, /* list matched file names only */
  39         OPTBIT_n, /* print line# */
  40         OPTBIT_q, /* quiet - exit(EXIT_SUCCESS) of first match */
  41         OPTBIT_v, /* invert the match, to select non-matching lines */
  42         OPTBIT_s, /* suppress errors about file open errors */
  43         OPTBIT_c, /* count matches per file (suppresses normal output) */
  44         OPTBIT_F, /* literal match */
  45         OPTBIT_i, /* case-insensitive */
  46         OPTBIT_H, /* force filename display */
  47         OPTBIT_h, /* inhibit filename display */
  48         OPTBIT_e, /* -e PATTERN */
  49         OPTBIT_f, /* -f FILE_WITH_PATTERNS */
  50         OPTBIT_L, /* list unmatched file names only */
  51         OPTBIT_o, /* show only matching parts of lines */
  52         OPTBIT_r, /* recurse dirs */
  53         OPTBIT_m, /* -m MAX_MATCHES */
  54         USE_FEATURE_GREP_CONTEXT(    OPTBIT_A ,) /* -A NUM: after-match context */
  55         USE_FEATURE_GREP_CONTEXT(    OPTBIT_B ,) /* -B NUM: before-match context */
  56         USE_FEATURE_GREP_CONTEXT(    OPTBIT_C ,) /* -C NUM: -A and -B combined */
  57         USE_FEATURE_GREP_EGREP_ALIAS(OPTBIT_E ,) /* extended regexp */
  58         USE_DESKTOP(                 OPTBIT_w ,) /* whole word match */
  59         USE_EXTRA_COMPAT(            OPTBIT_z ,) /* input is NUL terminated */
  60         OPT_l = 1 << OPTBIT_l,
  61         OPT_n = 1 << OPTBIT_n,
  62         OPT_q = 1 << OPTBIT_q,
  63         OPT_v = 1 << OPTBIT_v,
  64         OPT_s = 1 << OPTBIT_s,
  65         OPT_c = 1 << OPTBIT_c,
  66         OPT_F = 1 << OPTBIT_F,
  67         OPT_i = 1 << OPTBIT_i,
  68         OPT_H = 1 << OPTBIT_H,
  69         OPT_h = 1 << OPTBIT_h,
  70         OPT_e = 1 << OPTBIT_e,
  71         OPT_f = 1 << OPTBIT_f,
  72         OPT_L = 1 << OPTBIT_L,
  73         OPT_o = 1 << OPTBIT_o,
  74         OPT_r = 1 << OPTBIT_r,
  75         OPT_m = 1 << OPTBIT_m,
  76         OPT_A = USE_FEATURE_GREP_CONTEXT(    (1 << OPTBIT_A)) + 0,
  77         OPT_B = USE_FEATURE_GREP_CONTEXT(    (1 << OPTBIT_B)) + 0,
  78         OPT_C = USE_FEATURE_GREP_CONTEXT(    (1 << OPTBIT_C)) + 0,
  79         OPT_E = USE_FEATURE_GREP_EGREP_ALIAS((1 << OPTBIT_E)) + 0,
  80         OPT_w = USE_DESKTOP(                 (1 << OPTBIT_w)) + 0,
  81         OPT_z = USE_EXTRA_COMPAT(            (1 << OPTBIT_z)) + 0,
  82 };
  83
  84 #define PRINT_FILES_WITH_MATCHES    (option_mask32 & OPT_l)
  85 #define PRINT_LINE_NUM              (option_mask32 & OPT_n)
  86 #define BE_QUIET                    (option_mask32 & OPT_q)
  87 #define SUPPRESS_ERR_MSGS           (option_mask32 & OPT_s)
  88 #define PRINT_MATCH_COUNTS          (option_mask32 & OPT_c)
  89 #define FGREP_FLAG                  (option_mask32 & OPT_F)
  90 #define PRINT_FILES_WITHOUT_MATCHES (option_mask32 & OPT_L)
  91 #define NUL_DELIMITED               (option_mask32 & OPT_z)
  92
  93 struct globals {
  94         int max_matches;
  95 #if !ENABLE_EXTRA_COMPAT
  96         int reflags;
  97 #else
  98         RE_TRANSLATE_TYPE case_fold; /* RE_TRANSLATE_TYPE is [[un]signed] char* */
  99 #endif
 100         smalluint invert_search;
 101         smalluint print_filename;
 102         smalluint open_errors;
 103 #if ENABLE_FEATURE_GREP_CONTEXT
 104         smalluint did_print_line;
 105         int lines_before;
 106         int lines_after;
 107         char **before_buf;
 108         USE_EXTRA_COMPAT(size_t *before_buf_size;)
 109         int last_line_printed;
 110 #endif
 111         /* globals used internally */
 112         llist_t *pattern_head;   /* growable list of patterns to match */
 113         const char *cur_file;    /* the current file we are reading */
 114 };
 115 #define G (*(struct globals*)&bb_common_bufsiz1)
 116 #define INIT_G() do { \
 117         struct G_sizecheck { \
 118                 char G_sizecheck[sizeof(G) > COMMON_BUFSIZE ? -1 : 1]; \
 119         }; \
 120 } while (0)
 121 #define max_matches       (G.max_matches         )
 122 #if !ENABLE_EXTRA_COMPAT
 123 #define reflags           (G.reflags             )
 124 #else
 125 #define case_fold         (G.case_fold           )
 126 /* http://www.delorie.com/gnu/docs/regex/regex_46.html */
 127 #define reflags           re_syntax_options
 128 #undef REG_NOSUB
 129 #undef REG_EXTENDED
 130 #undef REG_ICASE
 131 #define REG_NOSUB    bug:is:here /* should not be used */
 132 #define REG_EXTENDED RE_SYNTAX_EGREP
 133 #define REG_ICASE    bug:is:here /* should not be used */
 134 #endif
 135 #define invert_search     (G.invert_search       )
 136 #define print_filename    (G.print_filename      )
 137 #define open_errors       (G.open_errors         )
 138 #define did_print_line    (G.did_print_line      )
 139 #define lines_before      (G.lines_before        )
 140 #define lines_after       (G.lines_after         )
 141 #define before_buf        (G.before_buf          )
 142 #define before_buf_size   (G.before_buf_size     )
 143 #define last_line_printed (G.last_line_printed   )
 144 #define pattern_head      (G.pattern_head        )
 145 #define cur_file          (G.cur_file            )
 146
 147
 148 typedef struct grep_list_data_t {
 149         char *pattern;
 150 /* for GNU regex, matched_range must be persistent across grep_file() calls */
 151 #if !ENABLE_EXTRA_COMPAT
 152         regex_t compiled_regex;
 153         regmatch_t matched_range;
 154 #else
 155         struct re_pattern_buffer compiled_regex;
 156         struct re_registers matched_range;
 157 #endif
 158 #define ALLOCATED 1
 159 #define COMPILED 2
 160         int flg_mem_alocated_compiled;
 161 } grep_list_data_t;
 162
 163 #if !ENABLE_EXTRA_COMPAT
 164 #define print_line(line, line_len, linenum, decoration) \
 165         print_line(line, linenum, decoration)
 166 #endif
 167 static void print_line(const char *line, size_t line_len, int linenum, char decoration)
 168 {
 169 #if ENABLE_FEATURE_GREP_CONTEXT
 170         /* Happens when we go to next file, immediately hit match
 171          * and try to print prev context... from prev file! Don't do it */
 172         if (linenum < 1)
 173                 return;
 174         /* possibly print the little '--' separator */
 175         if ((lines_before || lines_after) && did_print_line
 176          && last_line_printed != linenum - 1
 177         ) {
 178                 puts("--");
 179         }
 180         /* guard against printing "--" before first line of first file */
 181         did_print_line = 1;
 182         last_line_printed = linenum;
 183 #endif
 184         if (print_filename)
 185                 printf("%s%c", cur_file, decoration);
 186         if (PRINT_LINE_NUM)
 187                 printf("%i%c", linenum, decoration);
 188         /* Emulate weird GNU grep behavior with -ov */
 189         if ((option_mask32 & (OPT_v|OPT_o)) != (OPT_v|OPT_o)) {
 190 #if !ENABLE_EXTRA_COMPAT
 191                 puts(line);
 192 #else
 193                 fwrite(line, 1, line_len, stdout);
 194                 putchar(NUL_DELIMITED ? '\0' : '\n');
 195 #endif
 196         }
 197 }
 198
 199 #if ENABLE_EXTRA_COMPAT
 200 /* Unlike getline, this one removes trailing '\n' */
 201 static ssize_t FAST_FUNC bb_getline(char **line_ptr, size_t *line_alloc_len, FILE *file)
 202 {
 203         ssize_t res_sz;
 204         char *line;
 205         int delim = (NUL_DELIMITED ? '\0' : '\n');
 206
 207         res_sz = getdelim(line_ptr, line_alloc_len, delim, file);
 208         line = *line_ptr;
 209
 210         if (res_sz > 0) {
 211                 if (line[res_sz - 1] == delim)
 212                         line[--res_sz] = '\0';
 213         } else {
 214                 free(line); /* uclibc allocates a buffer even on EOF. WTF? */
 215         }
 216         return res_sz;
 217 }
 218 #endif
 219
 220 static int grep_file(FILE *file)
 221 {
 222         smalluint found;
 223         int linenum = 0;
 224         int nmatches = 0;
 225 #if !ENABLE_EXTRA_COMPAT
 226         char *line;
 227 #else
 228         char *line = NULL;
 229         ssize_t line_len;
 230         size_t line_alloc_len;
 231 #define rm_so start[0]
 232 #define rm_eo end[0]
 233 #endif
 234 #if ENABLE_FEATURE_GREP_CONTEXT
 235         int print_n_lines_after = 0;
 236         int curpos = 0; /* track where we are in the circular 'before' buffer */
 237         int idx = 0; /* used for iteration through the circular buffer */
 238 #else
 239         enum { print_n_lines_after = 0 };
 240 #endif /* ENABLE_FEATURE_GREP_CONTEXT */
 241
 242         while (
 243 #if !ENABLE_EXTRA_COMPAT
 244                 (line = xmalloc_fgetline(file)) != NULL
 245 #else
 246                 (line_len = bb_getline(&line, &line_alloc_len, file)) >= 0
 247 #endif
 248         ) {
 249                 llist_t *pattern_ptr = pattern_head;
 250                 grep_list_data_t *gl = gl; /* for gcc */
 251
 252                 linenum++;
 253                 found = 0;
 254                 while (pattern_ptr) {
 255                         gl = (grep_list_data_t *)pattern_ptr->data;
 256                         if (FGREP_FLAG) {
 257                                 found |= (strstr(line, gl->pattern) != NULL);
 258                         } else {
 259                                 if (!(gl->flg_mem_alocated_compiled & COMPILED)) {
 260                                         gl->flg_mem_alocated_compiled |= COMPILED;
 261 #if !ENABLE_EXTRA_COMPAT
 262                                         xregcomp(&gl->compiled_regex, gl->pattern, reflags);
 263 #else
 264                                         memset(&gl->compiled_regex, 0, sizeof(gl->compiled_regex));
 265                                         gl->compiled_regex.translate = case_fold; /* for -i */
 266                                         if (re_compile_pattern(gl->pattern, strlen(gl->pattern), &gl->compiled_regex))
 267                                                 bb_error_msg_and_die("bad regex '%s'", gl->pattern);
 268 #endif
 269                                 }
 270 #if !ENABLE_EXTRA_COMPAT
 271                                 gl->matched_range.rm_so = 0;
 272                                 gl->matched_range.rm_eo = 0;
 273 #endif
 274                                 if (
 275 #if !ENABLE_EXTRA_COMPAT
 276                                         regexec(&gl->compiled_regex, line, 1, &gl->matched_range, 0) == 0
 277 #else
 278                                         re_search(&gl->compiled_regex, line, line_len,
 279                                                         /*start:*/ 0, /*range:*/ line_len,
 280                                                         &gl->matched_range) >= 0
 281 #endif
 282                                 ) {
 283                                         if (!(option_mask32 & OPT_w))
 284                                                 found = 1;
 285                                         else {
 286                                                 char c = ' ';
 287                                                 if (gl->matched_range.rm_so)
 288                                                         c = line[gl->matched_range.rm_so - 1];
 289                                                 if (!isalnum(c) && c != '_') {
 290                                                         c = line[gl->matched_range.rm_eo];
 291                                                         if (!c || (!isalnum(c) && c != '_'))
 292                                                                 found = 1;
 293                                                 }
 294                                         }
 295                                 }
 296                         }
 297                         /* If it's non-inverted search, we can stop
 298                          * at first match */
 299                         if (found && !invert_search)
 300                                 goto do_found;
 301                         pattern_ptr = pattern_ptr->link;
 302                 } /* while (pattern_ptr) */
 303
 304                 if (found ^ invert_search) {
 305  do_found:
 306                         /* keep track of matches */
 307                         nmatches++;
 308
 309                         /* quiet/print (non)matching file names only? */
 310                         if (option_mask32 & (OPT_q|OPT_l|OPT_L)) {
 311                                 free(line); /* we don't need line anymore */
 312                                 if (BE_QUIET) {
 313                                         /* manpage says about -q:
 314                                          * "exit immediately with zero status
 315                                          * if any match is found,
 316                                          * even if errors were detected" */
 317                                         exit(EXIT_SUCCESS);
 318                                 }
 319                                 /* if we're just printing filenames, we stop after the first match */
 320                                 if (PRINT_FILES_WITH_MATCHES) {
 321                                         puts(cur_file);
 322                                         /* fall through to "return 1" */
 323                                 }
 324                                 /* OPT_L aka PRINT_FILES_WITHOUT_MATCHES: return early */
 325                                 return 1; /* one match */
 326                         }
 327
 328 #if ENABLE_FEATURE_GREP_CONTEXT
 329                         /* Were we printing context and saw next (unwanted) match? */
 330                         if ((option_mask32 & OPT_m) && nmatches > max_matches)
 331                                 break;
 332 #endif
 333
 334                         /* print the matched line */
 335                         if (PRINT_MATCH_COUNTS == 0) {
 336 #if ENABLE_FEATURE_GREP_CONTEXT
 337                                 int prevpos = (curpos == 0) ? lines_before - 1 : curpos - 1;
 338
 339                                 /* if we were told to print 'before' lines and there is at least
 340                                  * one line in the circular buffer, print them */
 341                                 if (lines_before && before_buf[prevpos] != NULL) {
 342                                         int first_buf_entry_line_num = linenum - lines_before;
 343
 344                                         /* advance to the first entry in the circular buffer, and
 345                                          * figure out the line number is of the first line in the
 346                                          * buffer */
 347                                         idx = curpos;
 348                                         while (before_buf[idx] == NULL) {
 349                                                 idx = (idx + 1) % lines_before;
 350                                                 first_buf_entry_line_num++;
 351                                         }
 352
 353                                         /* now print each line in the buffer, clearing them as we go */
 354                                         while (before_buf[idx] != NULL) {
 355                                                 print_line(before_buf[idx], before_buf_size[idx], first_buf_entry_line_num, '-');
 356                                                 free(before_buf[idx]);
 357                                                 before_buf[idx] = NULL;
 358                                                 idx = (idx + 1) % lines_before;
 359                                                 first_buf_entry_line_num++;
 360                                         }
 361                                 }
 362
 363                                 /* make a note that we need to print 'after' lines */
 364                                 print_n_lines_after = lines_after;
 365 #endif
 366                                 if (option_mask32 & OPT_o) {
 367                                         if (FGREP_FLAG) {
 368                                                 /* -Fo just prints the pattern
 369                                                  * (unless -v: -Fov doesnt print anything at all) */
 370                                                 if (found)
 371                                                         print_line(gl->pattern, strlen(gl->pattern), linenum, ':');
 372                                         } else while (1) {
 373                                                 char old = line[gl->matched_range.rm_eo];
 374                                                 line[gl->matched_range.rm_eo] = '\0';
 375                                                 print_line(line + gl->matched_range.rm_so,
 376                                                                 gl->matched_range.rm_eo - gl->matched_range.rm_so,
 377                                                                 linenum, ':');
 378                                                 line[gl->matched_range.rm_eo] = old;
 379 #if !ENABLE_EXTRA_COMPAT
 380                                                 break;
 381 #else
 382                                                 if (re_search(&gl->compiled_regex, line, line_len,
 383                                                                 gl->matched_range.rm_eo, line_len - gl->matched_range.rm_eo,
 384                                                                 &gl->matched_range) < 0)
 385                                                         break;
 386 #endif
 387                                         }
 388                                 } else {
 389                                         print_line(line, line_len, linenum, ':');
 390                                 }
 391                         }
 392                 }
 393 #if ENABLE_FEATURE_GREP_CONTEXT
 394                 else { /* no match */
 395                         /* if we need to print some context lines after the last match, do so */
 396                         if (print_n_lines_after) {
 397                                 print_line(line, strlen(line), linenum, '-');
 398                                 print_n_lines_after--;
 399                         } else if (lines_before) {
 400                                 /* Add the line to the circular 'before' buffer */
 401                                 free(before_buf[curpos]);
 402                                 before_buf[curpos] = line;
 403                                 USE_EXTRA_COMPAT(before_buf_size[curpos] = line_len;)
 404                                 curpos = (curpos + 1) % lines_before;
 405                                 /* avoid free(line) - we took the line */
 406                                 line = NULL;
 407                         }
 408                 }
 409
 410 #endif /* ENABLE_FEATURE_GREP_CONTEXT */
 411 #if !ENABLE_EXTRA_COMPAT
 412                 free(line);
 413 #endif
 414                 /* Did we print all context after last requested match? */
 415                 if ((option_mask32 & OPT_m)
 416                  && !print_n_lines_after
 417                  && nmatches == max_matches
 418                 ) {
 419                         break;
 420                 }
 421         } /* while (read line) */
 422
 423         /* special-case file post-processing for options where we don't print line
 424          * matches, just filenames and possibly match counts */
 425
 426         /* grep -c: print [filename:]count, even if count is zero */
 427         if (PRINT_MATCH_COUNTS) {
 428                 if (print_filename)
 429                         printf("%s:", cur_file);
 430                 printf("%d\n", nmatches);
 431         }
 432
 433         /* grep -L: print just the filename */
 434         if (PRINT_FILES_WITHOUT_MATCHES) {
 435                 /* nmatches is zero, no need to check it:
 436                  * we return 1 early if we detected a match
 437                  * and PRINT_FILES_WITHOUT_MATCHES is set */
 438                 puts(cur_file);
 439         }
 440
 441         return nmatches;
 442 }
 443
 444 #if ENABLE_FEATURE_CLEAN_UP
 445 #define new_grep_list_data(p, m) add_grep_list_data(p, m)
 446 static char *add_grep_list_data(char *pattern, int flg_used_mem)
 447 #else
 448 #define new_grep_list_data(p, m) add_grep_list_data(p)
 449 static char *add_grep_list_data(char *pattern)
 450 #endif
 451 {
 452         grep_list_data_t *gl = xzalloc(sizeof(*gl));
 453         gl->pattern = pattern;
 454 #if ENABLE_FEATURE_CLEAN_UP
 455         gl->flg_mem_alocated_compiled = flg_used_mem;
 456 #else
 457         /*gl->flg_mem_alocated_compiled = 0;*/
 458 #endif
 459         return (char *)gl;
 460 }
 461
 462 static void load_regexes_from_file(llist_t *fopt)
 463 {
 464         char *line;
 465         FILE *f;
 466
 467         while (fopt) {
 468                 llist_t *cur = fopt;
 469                 char *ffile = cur->data;
 470
 471                 fopt = cur->link;
 472                 free(cur);
 473                 f = xfopen_stdin(ffile);
 474                 while ((line = xmalloc_fgetline(f)) != NULL) {
 475                         llist_add_to(&pattern_head,
 476                                 new_grep_list_data(line, ALLOCATED));
 477                 }
 478         }
 479 }
 480
 481 static int FAST_FUNC file_action_grep(const char *filename,
 482                         struct stat *statbuf UNUSED_PARAM,
 483                         void* matched,
 484                         int depth UNUSED_PARAM)
 485 {
 486         FILE *file = fopen_for_read(filename);
 487         if (file == NULL) {
 488                 if (!SUPPRESS_ERR_MSGS)
 489                         bb_simple_perror_msg(filename);
 490                 open_errors = 1;
 491                 return 0;
 492         }
 493         cur_file = filename;
 494         *(int*)matched += grep_file(file);
 495         fclose(file);
 496         return 1;
 497 }
 498
 499 static int grep_dir(const char *dir)
 500 {
 501         int matched = 0;
 502         recursive_action(dir,
 503                 /* recurse=yes */ ACTION_RECURSE |
 504                 /* followLinks=no */
 505                 /* depthFirst=yes */ ACTION_DEPTHFIRST,
 506                 /* fileAction= */ file_action_grep,
 507                 /* dirAction= */ NULL,
 508                 /* userData= */ &matched,
 509                 /* depth= */ 0);
 510         return matched;
 511 }
 512
 513 int grep_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 514 int grep_main(int argc, char **argv)
 515 {
 516         FILE *file;
 517         int matched;
 518         llist_t *fopt = NULL;
 519
 520         /* do normal option parsing */
 521 #if ENABLE_FEATURE_GREP_CONTEXT
 522         int Copt;
 523
 524         /* -H unsets -h; -C unsets -A,-B; -e,-f are lists;
 525          * -m,-A,-B,-C have numeric param */
 526         opt_complementary = "H-h:C-AB:e::f::m+:A+:B+:C+";
 527         getopt32(argv,
 528                 OPTSTR_GREP,
 529                 &pattern_head, &fopt, &max_matches,
 530                 &lines_after, &lines_before, &Copt);
 531
 532         if (option_mask32 & OPT_C) {
 533                 /* -C unsets prev -A and -B, but following -A or -B
 534                    may override it */
 535                 if (!(option_mask32 & OPT_A)) /* not overridden */
 536                         lines_after = Copt;
 537                 if (!(option_mask32 & OPT_B)) /* not overridden */
 538                         lines_before = Copt;
 539         }
 540         /* sanity checks */
 541         if (option_mask32 & (OPT_c|OPT_q|OPT_l|OPT_L)) {
 542                 option_mask32 &= ~OPT_n;
 543                 lines_before = 0;
 544                 lines_after = 0;
 545         } else if (lines_before > 0) {
 546                 before_buf = xzalloc(lines_before * sizeof(before_buf[0]));
 547                 USE_EXTRA_COMPAT(before_buf_size = xzalloc(lines_before * sizeof(before_buf_size[0]));)
 548         }
 549 #else
 550         /* with auto sanity checks */
 551         /* -H unsets -h; -c,-q or -l unset -n; -e,-f are lists; -m N */
 552         opt_complementary = "H-h:c-n:q-n:l-n:e::f::m+";
 553         getopt32(argv, OPTSTR_GREP,
 554                 &pattern_head, &fopt, &max_matches);
 555 #endif
 556         invert_search = ((option_mask32 & OPT_v) != 0); /* 0 | 1 */
 557
 558         if (pattern_head != NULL) {
 559                 /* convert char **argv to grep_list_data_t */
 560                 llist_t *cur;
 561
 562                 for (cur = pattern_head; cur; cur = cur->link)
 563                         cur->data = new_grep_list_data(cur->data, 0);
 564         }
 565         if (option_mask32 & OPT_f)
 566                 load_regexes_from_file(fopt);
 567
 568         if (ENABLE_FEATURE_GREP_FGREP_ALIAS && applet_name[0] == 'f')
 569                 option_mask32 |= OPT_F;
 570
 571 #if !ENABLE_EXTRA_COMPAT
 572         if (!(option_mask32 & (OPT_o | OPT_w)))
 573                 reflags = REG_NOSUB;
 574 #endif
 575
 576         if (ENABLE_FEATURE_GREP_EGREP_ALIAS
 577          && (applet_name[0] == 'e' || (option_mask32 & OPT_E))
 578         ) {
 579                 reflags |= REG_EXTENDED;
 580         }
 581 #if ENABLE_EXTRA_COMPAT
 582         else {
 583                 reflags = RE_SYNTAX_GREP;
 584         }
 585 #endif
 586
 587         if (option_mask32 & OPT_i) {
 588 #if !ENABLE_EXTRA_COMPAT
 589                 reflags |= REG_ICASE;
 590 #else
 591                 int i;
 592                 case_fold = xmalloc(256);
 593                 for (i = 0; i < 256; i++)
 594                         case_fold[i] = (unsigned char)i;
 595                 for (i = 'a'; i <= 'z'; i++)
 596                         case_fold[i] = (unsigned char)(i - ('a' - 'A'));
 597 #endif
 598         }
 599
 600         argv += optind;
 601         argc -= optind;
 602
 603         /* if we didn't get a pattern from -e and no command file was specified,
 604          * first parameter should be the pattern. no pattern, no worky */
 605         if (pattern_head == NULL) {
 606                 char *pattern;
 607                 if (*argv == NULL)
 608                         bb_show_usage();
 609                 pattern = new_grep_list_data(*argv++, 0);
 610                 llist_add_to(&pattern_head, pattern);
 611                 argc--;
 612         }
 613
 614         /* argv[0..(argc-1)] should be names of file to grep through. If
 615          * there is more than one file to grep, we will print the filenames. */
 616         if (argc > 1)
 617                 print_filename = 1;
 618         /* -H / -h of course override */
 619         if (option_mask32 & OPT_H)
 620                 print_filename = 1;
 621         if (option_mask32 & OPT_h)
 622                 print_filename = 0;
 623
 624         /* If no files were specified, or '-' was specified, take input from
 625          * stdin. Otherwise, we grep through all the files specified. */
 626         matched = 0;
 627         do {
 628                 cur_file = *argv++;
 629                 file = stdin;
 630                 if (!cur_file || LONE_DASH(cur_file)) {
 631                         cur_file = "(standard input)";
 632                 } else {
 633                         if (option_mask32 & OPT_r) {
 634                                 struct stat st;
 635                                 if (stat(cur_file, &st) == 0 && S_ISDIR(st.st_mode)) {
 636                                         if (!(option_mask32 & OPT_h))
 637                                                 print_filename = 1;
 638                                         matched += grep_dir(cur_file);
 639                                         goto grep_done;
 640                                 }
 641                         }
 642                         /* else: fopen(dir) will succeed, but reading won't */
 643                         file = fopen_for_read(cur_file);
 644                         if (file == NULL) {
 645                                 if (!SUPPRESS_ERR_MSGS)
 646                                         bb_simple_perror_msg(cur_file);
 647                                 open_errors = 1;
 648                                 continue;
 649                         }
 650                 }
 651                 matched += grep_file(file);
 652                 fclose_if_not_stdin(file);
 653  grep_done: ;
 654         } while (--argc > 0);
 655
 656         /* destroy all the elments in the pattern list */
 657         if (ENABLE_FEATURE_CLEAN_UP) {
 658                 while (pattern_head) {
 659                         llist_t *pattern_head_ptr = pattern_head;
 660                         grep_list_data_t *gl = (grep_list_data_t *)pattern_head_ptr->data;
 661
 662                         pattern_head = pattern_head->link;
 663                         if (gl->flg_mem_alocated_compiled & ALLOCATED)
 664                                 free(gl->pattern);
 665                         if (gl->flg_mem_alocated_compiled & COMPILED)
 666                                 regfree(&gl->compiled_regex);
 667                         free(gl);
 668                         free(pattern_head_ptr);
 669                 }
 670         }
 671         /* 0 = success, 1 = failed, 2 = error */
 672         if (open_errors)
 673                 return 2;
 674         return !matched; /* invert return value: 0 = success, 1 = failed */
 675 }