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 while (1) {
 367                                                 char old = line[gl->matched_range.rm_eo];
 368                                                 line[gl->matched_range.rm_eo] = '\0';
 369                                                 print_line(line + gl->matched_range.rm_so,
 370                                                                 gl->matched_range.rm_eo - gl->matched_range.rm_so,
 371                                                                 linenum, ':');
 372                                                 line[gl->matched_range.rm_eo] = old;
 373 #if !ENABLE_EXTRA_COMPAT
 374                                                 break;
 375 #else
 376                                                 if (re_search(&gl->compiled_regex, line, line_len,
 377                                                                 gl->matched_range.rm_eo, line_len - gl->matched_range.rm_eo,
 378                                                                 &gl->matched_range) < 0)
 379                                                         break;
 380 #endif
 381                                         }
 382                                 } else {
 383                                         print_line(line, line_len, linenum, ':');
 384                                 }
 385                         }
 386                 }
 387 #if ENABLE_FEATURE_GREP_CONTEXT
 388                 else { /* no match */
 389                         /* if we need to print some context lines after the last match, do so */
 390                         if (print_n_lines_after) {
 391                                 print_line(line, strlen(line), linenum, '-');
 392                                 print_n_lines_after--;
 393                         } else if (lines_before) {
 394                                 /* Add the line to the circular 'before' buffer */
 395                                 free(before_buf[curpos]);
 396                                 before_buf[curpos] = line;
 397                                 USE_EXTRA_COMPAT(before_buf_size[curpos] = line_len;)
 398                                 curpos = (curpos + 1) % lines_before;
 399                                 /* avoid free(line) - we took the line */
 400                                 line = NULL;
 401                         }
 402                 }
 403
 404 #endif /* ENABLE_FEATURE_GREP_CONTEXT */
 405 #if !ENABLE_EXTRA_COMPAT
 406                 free(line);
 407 #endif
 408                 /* Did we print all context after last requested match? */
 409                 if ((option_mask32 & OPT_m)
 410                  && !print_n_lines_after && nmatches == max_matches)
 411                         break;
 412         } /* while (read line) */
 413
 414         /* special-case file post-processing for options where we don't print line
 415          * matches, just filenames and possibly match counts */
 416
 417         /* grep -c: print [filename:]count, even if count is zero */
 418         if (PRINT_MATCH_COUNTS) {
 419                 if (print_filename)
 420                         printf("%s:", cur_file);
 421                 printf("%d\n", nmatches);
 422         }
 423
 424         /* grep -L: print just the filename */
 425         if (PRINT_FILES_WITHOUT_MATCHES) {
 426                 /* nmatches is zero, no need to check it:
 427                  * we return 1 early if we detected a match
 428                  * and PRINT_FILES_WITHOUT_MATCHES is set */
 429                 puts(cur_file);
 430         }
 431
 432         return nmatches;
 433 }
 434
 435 #if ENABLE_FEATURE_CLEAN_UP
 436 #define new_grep_list_data(p, m) add_grep_list_data(p, m)
 437 static char *add_grep_list_data(char *pattern, int flg_used_mem)
 438 #else
 439 #define new_grep_list_data(p, m) add_grep_list_data(p)
 440 static char *add_grep_list_data(char *pattern)
 441 #endif
 442 {
 443         grep_list_data_t *gl = xzalloc(sizeof(*gl));
 444         gl->pattern = pattern;
 445 #if ENABLE_FEATURE_CLEAN_UP
 446         gl->flg_mem_alocated_compiled = flg_used_mem;
 447 #else
 448         /*gl->flg_mem_alocated_compiled = 0;*/
 449 #endif
 450         return (char *)gl;
 451 }
 452
 453 static void load_regexes_from_file(llist_t *fopt)
 454 {
 455         char *line;
 456         FILE *f;
 457
 458         while (fopt) {
 459                 llist_t *cur = fopt;
 460                 char *ffile = cur->data;
 461
 462                 fopt = cur->link;
 463                 free(cur);
 464                 f = xfopen_stdin(ffile);
 465                 while ((line = xmalloc_fgetline(f)) != NULL) {
 466                         llist_add_to(&pattern_head,
 467                                 new_grep_list_data(line, ALLOCATED));
 468                 }
 469         }
 470 }
 471
 472 static int FAST_FUNC file_action_grep(const char *filename,
 473                         struct stat *statbuf UNUSED_PARAM,
 474                         void* matched,
 475                         int depth UNUSED_PARAM)
 476 {
 477         FILE *file = fopen_for_read(filename);
 478         if (file == NULL) {
 479                 if (!SUPPRESS_ERR_MSGS)
 480                         bb_simple_perror_msg(filename);
 481                 open_errors = 1;
 482                 return 0;
 483         }
 484         cur_file = filename;
 485         *(int*)matched += grep_file(file);
 486         fclose(file);
 487         return 1;
 488 }
 489
 490 static int grep_dir(const char *dir)
 491 {
 492         int matched = 0;
 493         recursive_action(dir,
 494                 /* recurse=yes */ ACTION_RECURSE |
 495                 /* followLinks=no */
 496                 /* depthFirst=yes */ ACTION_DEPTHFIRST,
 497                 /* fileAction= */ file_action_grep,
 498                 /* dirAction= */ NULL,
 499                 /* userData= */ &matched,
 500                 /* depth= */ 0);
 501         return matched;
 502 }
 503
 504 int grep_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 505 int grep_main(int argc, char **argv)
 506 {
 507         FILE *file;
 508         int matched;
 509         llist_t *fopt = NULL;
 510
 511         /* do normal option parsing */
 512 #if ENABLE_FEATURE_GREP_CONTEXT
 513         int Copt;
 514
 515         /* -H unsets -h; -C unsets -A,-B; -e,-f are lists;
 516          * -m,-A,-B,-C have numeric param */
 517         opt_complementary = "H-h:C-AB:e::f::m+:A+:B+:C+";
 518         getopt32(argv,
 519                 OPTSTR_GREP,
 520                 &pattern_head, &fopt, &max_matches,
 521                 &lines_after, &lines_before, &Copt);
 522
 523         if (option_mask32 & OPT_C) {
 524                 /* -C unsets prev -A and -B, but following -A or -B
 525                    may override it */
 526                 if (!(option_mask32 & OPT_A)) /* not overridden */
 527                         lines_after = Copt;
 528                 if (!(option_mask32 & OPT_B)) /* not overridden */
 529                         lines_before = Copt;
 530         }
 531         /* sanity checks */
 532         if (option_mask32 & (OPT_c|OPT_q|OPT_l|OPT_L)) {
 533                 option_mask32 &= ~OPT_n;
 534                 lines_before = 0;
 535                 lines_after = 0;
 536         } else if (lines_before > 0) {
 537                 before_buf = xzalloc(lines_before * sizeof(before_buf[0]));
 538                 USE_EXTRA_COMPAT(before_buf_size = xzalloc(lines_before * sizeof(before_buf_size[0]));)
 539         }
 540 #else
 541         /* with auto sanity checks */
 542         /* -H unsets -h; -c,-q or -l unset -n; -e,-f are lists; -m N */
 543         opt_complementary = "H-h:c-n:q-n:l-n:e::f::m+";
 544         getopt32(argv, OPTSTR_GREP,
 545                 &pattern_head, &fopt, &max_matches);
 546 #endif
 547         invert_search = ((option_mask32 & OPT_v) != 0); /* 0 | 1 */
 548
 549         if (pattern_head != NULL) {
 550                 /* convert char **argv to grep_list_data_t */
 551                 llist_t *cur;
 552
 553                 for (cur = pattern_head; cur; cur = cur->link)
 554                         cur->data = new_grep_list_data(cur->data, 0);
 555         }
 556         if (option_mask32 & OPT_f)
 557                 load_regexes_from_file(fopt);
 558
 559         if (ENABLE_FEATURE_GREP_FGREP_ALIAS && applet_name[0] == 'f')
 560                 option_mask32 |= OPT_F;
 561
 562 #if !ENABLE_EXTRA_COMPAT
 563         if (!(option_mask32 & (OPT_o | OPT_w)))
 564                 reflags = REG_NOSUB;
 565 #endif
 566
 567         if (ENABLE_FEATURE_GREP_EGREP_ALIAS
 568          && (applet_name[0] == 'e' || (option_mask32 & OPT_E))
 569         ) {
 570                 reflags |= REG_EXTENDED;
 571         }
 572 #if ENABLE_EXTRA_COMPAT
 573         else {
 574                 reflags = RE_SYNTAX_GREP;
 575         }
 576 #endif
 577
 578         if (option_mask32 & OPT_i) {
 579 #if !ENABLE_EXTRA_COMPAT
 580                 reflags |= REG_ICASE;
 581 #else
 582                 int i;
 583                 case_fold = xmalloc(256);
 584                 for (i = 0; i < 256; i++)
 585                         case_fold[i] = (unsigned char)i;
 586                 for (i = 'a'; i <= 'z'; i++)
 587                         case_fold[i] = (unsigned char)(i - ('a' - 'A'));
 588 #endif
 589         }
 590
 591         argv += optind;
 592         argc -= optind;
 593
 594         /* if we didn't get a pattern from -e and no command file was specified,
 595          * first parameter should be the pattern. no pattern, no worky */
 596         if (pattern_head == NULL) {
 597                 char *pattern;
 598                 if (*argv == NULL)
 599                         bb_show_usage();
 600                 pattern = new_grep_list_data(*argv++, 0);
 601                 llist_add_to(&pattern_head, pattern);
 602                 argc--;
 603         }
 604
 605         /* argv[0..(argc-1)] should be names of file to grep through. If
 606          * there is more than one file to grep, we will print the filenames. */
 607         if (argc > 1)
 608                 print_filename = 1;
 609         /* -H / -h of course override */
 610         if (option_mask32 & OPT_H)
 611                 print_filename = 1;
 612         if (option_mask32 & OPT_h)
 613                 print_filename = 0;
 614
 615         /* If no files were specified, or '-' was specified, take input from
 616          * stdin. Otherwise, we grep through all the files specified. */
 617         matched = 0;
 618         do {
 619                 cur_file = *argv++;
 620                 file = stdin;
 621                 if (!cur_file || LONE_DASH(cur_file)) {
 622                         cur_file = "(standard input)";
 623                 } else {
 624                         if (option_mask32 & OPT_r) {
 625                                 struct stat st;
 626                                 if (stat(cur_file, &st) == 0 && S_ISDIR(st.st_mode)) {
 627                                         if (!(option_mask32 & OPT_h))
 628                                                 print_filename = 1;
 629                                         matched += grep_dir(cur_file);
 630                                         goto grep_done;
 631                                 }
 632                         }
 633                         /* else: fopen(dir) will succeed, but reading won't */
 634                         file = fopen_for_read(cur_file);
 635                         if (file == NULL) {
 636                                 if (!SUPPRESS_ERR_MSGS)
 637                                         bb_simple_perror_msg(cur_file);
 638                                 open_errors = 1;
 639                                 continue;
 640                         }
 641                 }
 642                 matched += grep_file(file);
 643                 fclose_if_not_stdin(file);
 644  grep_done: ;
 645         } while (--argc > 0);
 646
 647         /* destroy all the elments in the pattern list */
 648         if (ENABLE_FEATURE_CLEAN_UP) {
 649                 while (pattern_head) {
 650                         llist_t *pattern_head_ptr = pattern_head;
 651                         grep_list_data_t *gl = (grep_list_data_t *)pattern_head_ptr->data;
 652
 653                         pattern_head = pattern_head->link;
 654                         if (gl->flg_mem_alocated_compiled & ALLOCATED)
 655                                 free(gl->pattern);
 656                         if (gl->flg_mem_alocated_compiled & COMPILED)
 657                                 regfree(&gl->compiled_regex);
 658                         free(gl);
 659                         free(pattern_head_ptr);
 660                 }
 661         }
 662         /* 0 = success, 1 = failed, 2 = error */
 663         if (open_errors)
 664                 return 2;
 665         return !matched; /* invert return value: 0 = success, 1 = failed */
 666 }