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