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.  */
  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(0) 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 typedef unsigned char byte_t;
  89
  90 static int max_matches;
  91 static int reflags;
  92 static byte_t invert_search;
  93 static byte_t print_filename;
  94 static byte_t open_errors;
  95
  96 #if ENABLE_FEATURE_GREP_CONTEXT
  97 static byte_t did_print_line;
  98 static int lines_before;
  99 static int lines_after;
 100 static char **before_buf;
 101 static int last_line_printed;
 102 #endif /* ENABLE_FEATURE_GREP_CONTEXT */
 103 /* globals used internally */
 104 static llist_t *pattern_head;   /* growable list of patterns to match */
 105 static const char *cur_file;    /* the current file we are reading */
 106
 107 typedef struct grep_list_data_t {
 108         char *pattern;
 109         regex_t preg;
 110 #define PATTERN_MEM_A 1
 111 #define COMPILED 2
 112         int flg_mem_alocated_compiled;
 113 } grep_list_data_t;
 114
 115 static void print_line(const char *line, int linenum, char decoration)
 116 {
 117 #if ENABLE_FEATURE_GREP_CONTEXT
 118         /* Happens when we go to next file, immediately hit match
 119          * and try to print prev context... from prev file! Don't do it */
 120         if (linenum < 1)
 121                 return;
 122         /* possibly print the little '--' separator */
 123         if ((lines_before || lines_after) && did_print_line &&
 124                         last_line_printed != linenum - 1) {
 125                 puts("--");
 126         }
 127         /* guard against printing "--" before first line of first file */
 128         did_print_line = 1;
 129         last_line_printed = linenum;
 130 #endif
 131         if (print_filename)
 132                 printf("%s%c", cur_file, decoration);
 133         if (PRINT_LINE_NUM)
 134                 printf("%i%c", linenum, decoration);
 135         /* Emulate weird GNU grep behavior with -ov */
 136         if ((option_mask32 & (OPT_v|OPT_o)) != (OPT_v|OPT_o))
 137                 puts(line);
 138 }
 139
 140 static int grep_file(FILE *file)
 141 {
 142         char *line;
 143         byte_t ret;
 144         int linenum = 0;
 145         int nmatches = 0;
 146         regmatch_t regmatch;
 147 #if ENABLE_FEATURE_GREP_CONTEXT
 148         int print_n_lines_after = 0;
 149         int curpos = 0; /* track where we are in the circular 'before' buffer */
 150         int idx = 0; /* used for iteration through the circular buffer */
 151 #else
 152         enum { print_n_lines_after = 0 };
 153 #endif /* ENABLE_FEATURE_GREP_CONTEXT */
 154
 155         while ((line = xmalloc_getline(file)) != NULL) {
 156                 llist_t *pattern_ptr = pattern_head;
 157                 grep_list_data_t * gl;
 158
 159                 linenum++;
 160                 ret = 0;
 161                 while (pattern_ptr) {
 162                         gl = (grep_list_data_t *)pattern_ptr->data;
 163                         if (FGREP_FLAG) {
 164                                 ret = strstr(line, gl->pattern) != NULL;
 165                         } else {
 166                                 /*
 167                                  * test for a postitive-assertion match (regexec returns success (0)
 168                                  * and the user did not specify invert search), or a negative-assertion
 169                                  * match (regexec returns failure (REG_NOMATCH) and the user specified
 170                                  * invert search)
 171                                  */
 172                                 if (!(gl->flg_mem_alocated_compiled & COMPILED)) {
 173                                         gl->flg_mem_alocated_compiled |= COMPILED;
 174                                         xregcomp(&(gl->preg), gl->pattern, reflags);
 175                                 }
 176                                 regmatch.rm_so = 0;
 177                                 regmatch.rm_eo = 0;
 178                                 if (regexec(&(gl->preg), line, 1, &regmatch, 0) == 0) {
 179                                         if (!(option_mask32 & OPT_w))
 180                                                 ret = 1;
 181                                         else {
 182                                                 char c = ' ';
 183                                                 if (regmatch.rm_so)
 184                                                         c = line[regmatch.rm_so - 1];
 185                                                 if (!isalnum(c) && c != '_') {
 186                                                         c = line[regmatch.rm_eo];
 187                                                         if (!c || (!isalnum(c) && c != '_'))
 188                                                                 ret = 1;
 189                                                 }
 190                                         }
 191                                 }
 192                         }
 193                         pattern_ptr = pattern_ptr->link;
 194                 } /* while (pattern_ptr) */
 195
 196                 if (ret ^ invert_search) {
 197                         /* keep track of matches */
 198                         nmatches++;
 199
 200                         /* quiet/print (non)matching file names only? */
 201                         if (option_mask32 & (OPT_q|OPT_l|OPT_L)) {
 202                                 free(line); /* we don't need line anymore */
 203                                 if (BE_QUIET) {
 204                                         /* manpage says about -q:
 205                                          * "exit immediately with zero status
 206                                          * if any match is found,
 207                                          * even if errors were detected" */
 208                                         exit(0);
 209                                 }
 210                                 /* if we're just printing filenames, we stop after the first match */
 211                                 if (PRINT_FILES_WITH_MATCHES) {
 212                                         puts(cur_file);
 213                                         /* fall thru to "return 1" */
 214                                 }
 215                                 /* OPT_L aka PRINT_FILES_WITHOUT_MATCHES: return early */
 216                                 return 1; /* one match */
 217                         }
 218
 219 #if ENABLE_FEATURE_GREP_CONTEXT
 220                         /* Were we printing context and saw next (unwanted) match? */
 221                         if ((option_mask32 & OPT_m) && nmatches > max_matches)
 222                                 break;
 223 #endif
 224
 225                         /* print the matched line */
 226                         if (PRINT_MATCH_COUNTS == 0) {
 227 #if ENABLE_FEATURE_GREP_CONTEXT
 228                                 int prevpos = (curpos == 0) ? lines_before - 1 : curpos - 1;
 229
 230                                 /* if we were told to print 'before' lines and there is at least
 231                                  * one line in the circular buffer, print them */
 232                                 if (lines_before && before_buf[prevpos] != NULL) {
 233                                         int first_buf_entry_line_num = linenum - lines_before;
 234
 235                                         /* advance to the first entry in the circular buffer, and
 236                                          * figure out the line number is of the first line in the
 237                                          * buffer */
 238                                         idx = curpos;
 239                                         while (before_buf[idx] == NULL) {
 240                                                 idx = (idx + 1) % lines_before;
 241                                                 first_buf_entry_line_num++;
 242                                         }
 243
 244                                         /* now print each line in the buffer, clearing them as we go */
 245                                         while (before_buf[idx] != NULL) {
 246                                                 print_line(before_buf[idx], first_buf_entry_line_num, '-');
 247                                                 free(before_buf[idx]);
 248                                                 before_buf[idx] = NULL;
 249                                                 idx = (idx + 1) % lines_before;
 250                                                 first_buf_entry_line_num++;
 251                                         }
 252                                 }
 253
 254                                 /* make a note that we need to print 'after' lines */
 255                                 print_n_lines_after = lines_after;
 256 #endif
 257                                 if (option_mask32 & OPT_o) {
 258                                         line[regmatch.rm_eo] = '\0';
 259                                         print_line(line + regmatch.rm_so, linenum, ':');
 260                                 } else {
 261                                         print_line(line, linenum, ':');
 262                                 }
 263                         }
 264                 }
 265 #if ENABLE_FEATURE_GREP_CONTEXT
 266                 else { /* no match */
 267                         /* if we need to print some context lines after the last match, do so */
 268                         if (print_n_lines_after) {
 269                                 print_line(line, linenum, '-');
 270                                 print_n_lines_after--;
 271                         } else if (lines_before) {
 272                                 /* Add the line to the circular 'before' buffer */
 273                                 free(before_buf[curpos]);
 274                                 before_buf[curpos] = line;
 275                                 curpos = (curpos + 1) % lines_before;
 276                                 /* avoid free(line) - we took line */
 277                                 line = NULL;
 278                         }
 279                 }
 280
 281 #endif /* ENABLE_FEATURE_GREP_CONTEXT */
 282                 free(line);
 283
 284                 /* Did we print all context after last requested match? */
 285                 if ((option_mask32 & OPT_m)
 286                  && !print_n_lines_after && nmatches == max_matches)
 287                         break;
 288         }
 289
 290         /* special-case file post-processing for options where we don't print line
 291          * matches, just filenames and possibly match counts */
 292
 293         /* grep -c: print [filename:]count, even if count is zero */
 294         if (PRINT_MATCH_COUNTS) {
 295                 if (print_filename)
 296                         printf("%s:", cur_file);
 297                 printf("%d\n", nmatches);
 298         }
 299
 300         /* grep -L: print just the filename */
 301         if (PRINT_FILES_WITHOUT_MATCHES) {
 302                 /* nmatches is zero, no need to check it:
 303                  * we return 1 early if we detected a match
 304                  * and PRINT_FILES_WITHOUT_MATCHES is set */
 305                 puts(cur_file);
 306         }
 307
 308         return nmatches;
 309 }
 310
 311 #if ENABLE_FEATURE_CLEAN_UP
 312 #define new_grep_list_data(p, m) add_grep_list_data(p, m)
 313 static char * add_grep_list_data(char *pattern, int flg_used_mem)
 314 #else
 315 #define new_grep_list_data(p, m) add_grep_list_data(p)
 316 static char * add_grep_list_data(char *pattern)
 317 #endif
 318 {
 319         grep_list_data_t *gl = xmalloc(sizeof(grep_list_data_t));
 320         gl->pattern = pattern;
 321 #if ENABLE_FEATURE_CLEAN_UP
 322         gl->flg_mem_alocated_compiled = flg_used_mem;
 323 #else
 324         gl->flg_mem_alocated_compiled = 0;
 325 #endif
 326         return (char *)gl;
 327 }
 328
 329 static void load_regexes_from_file(llist_t *fopt)
 330 {
 331         char *line;
 332         FILE *f;
 333
 334         while (fopt) {
 335                 llist_t *cur = fopt;
 336                 char *ffile = cur->data;
 337
 338                 fopt = cur->link;
 339                 free(cur);
 340                 f = xfopen(ffile, "r");
 341                 while ((line = xmalloc_getline(f)) != NULL) {
 342                         llist_add_to(&pattern_head,
 343                                 new_grep_list_data(line, PATTERN_MEM_A));
 344                 }
 345         }
 346 }
 347
 348 static int file_action_grep(const char *filename, struct stat *statbuf, void* matched, int depth)
 349 {
 350         FILE *file = fopen(filename, "r");
 351         if (file == NULL) {
 352                 if (!SUPPRESS_ERR_MSGS)
 353                         bb_perror_msg("%s", cur_file);
 354                 open_errors = 1;
 355                 return 0;
 356         }
 357         cur_file = filename;
 358         *(int*)matched += grep_file(file);
 359         fclose(file);
 360         return 1;
 361 }
 362
 363 static int grep_dir(const char *dir)
 364 {
 365         int matched = 0;
 366         recursive_action(dir,
 367                 /* recurse=yes */ ACTION_RECURSE |
 368                 /* followLinks=no */
 369                 /* depthFirst=yes */ ACTION_DEPTHFIRST,
 370                 /* fileAction= */ file_action_grep,
 371                 /* dirAction= */ NULL,
 372                 /* userData= */ &matched,
 373                 /* depth= */ 0);
 374         return matched;
 375 }
 376
 377 int grep_main(int argc, char **argv);
 378 int grep_main(int argc, char **argv)
 379 {
 380         FILE *file;
 381         int matched;
 382         char *mopt;
 383         llist_t *fopt = NULL;
 384
 385         /* do normal option parsing */
 386 #if ENABLE_FEATURE_GREP_CONTEXT
 387         char *slines_after;
 388         char *slines_before;
 389         char *Copt;
 390
 391         opt_complementary = "H-h:e::f::C-AB";
 392         getopt32(argv,
 393                 OPTSTR_GREP,
 394                 &pattern_head, &fopt, &mopt,
 395                 &slines_after, &slines_before, &Copt);
 396
 397         if (option_mask32 & OPT_C) {
 398                 /* -C unsets prev -A and -B, but following -A or -B
 399                    may override it */
 400                 if (!(option_mask32 & OPT_A)) /* not overridden */
 401                         slines_after = Copt;
 402                 if (!(option_mask32 & OPT_B)) /* not overridden */
 403                         slines_before = Copt;
 404                 option_mask32 |= OPT_A|OPT_B; /* for parser */
 405         }
 406         if (option_mask32 & OPT_A) {
 407                 lines_after = xatoi_u(slines_after);
 408         }
 409         if (option_mask32 & OPT_B) {
 410                 lines_before = xatoi_u(slines_before);
 411         }
 412         /* sanity checks */
 413         if (option_mask32 & (OPT_c|OPT_q|OPT_l|OPT_L)) {
 414                 option_mask32 &= ~OPT_n;
 415                 lines_before = 0;
 416                 lines_after = 0;
 417         } else if (lines_before > 0)
 418                 before_buf = xzalloc(lines_before * sizeof(char *));
 419 #else
 420         /* with auto sanity checks */
 421         opt_complementary = "H-h:e::f::c-n:q-n:l-n";
 422         getopt32(argv, OPTSTR_GREP,
 423                 &pattern_head, &fopt, &mopt);
 424 #endif
 425         if (option_mask32 & OPT_m) {
 426                 max_matches = xatoi_u(mopt);
 427         }
 428         invert_search = ((option_mask32 & OPT_v) != 0); /* 0 | 1 */
 429
 430         if (pattern_head != NULL) {
 431                 /* convert char **argv to grep_list_data_t */
 432                 llist_t *cur;
 433
 434                 for (cur = pattern_head; cur; cur = cur->link)
 435                         cur->data = new_grep_list_data(cur->data, 0);
 436         }
 437         if (option_mask32 & OPT_f)
 438                 load_regexes_from_file(fopt);
 439
 440         if (ENABLE_FEATURE_GREP_FGREP_ALIAS && applet_name[0] == 'f')
 441                 option_mask32 |= OPT_F;
 442
 443         if (!(option_mask32 & (OPT_o | OPT_w)))
 444                 reflags = REG_NOSUB;
 445
 446         if (ENABLE_FEATURE_GREP_EGREP_ALIAS &&
 447                         (applet_name[0] == 'e' || (option_mask32 & OPT_E)))
 448                 reflags |= REG_EXTENDED;
 449
 450         if (option_mask32 & OPT_i)
 451                 reflags |= REG_ICASE;
 452
 453         argv += optind;
 454         argc -= optind;
 455
 456         /* if we didn't get a pattern from a -e and no command file was specified,
 457          * argv[optind] should be the pattern. no pattern, no worky */
 458         if (pattern_head == NULL) {
 459                 char *pattern;
 460                 if (*argv == NULL)
 461                         bb_show_usage();
 462                 pattern = new_grep_list_data(*argv++, 0);
 463                 llist_add_to(&pattern_head, pattern);
 464                 argc--;
 465         }
 466
 467         /* argv[(optind)..(argc-1)] should be names of file to grep through. If
 468          * there is more than one file to grep, we will print the filenames. */
 469         if (argc > 1)
 470                 print_filename = 1;
 471         /* -H / -h of course override */
 472         if (option_mask32 & OPT_H)
 473                 print_filename = 1;
 474         if (option_mask32 & OPT_h)
 475                 print_filename = 0;
 476
 477         /* If no files were specified, or '-' was specified, take input from
 478          * stdin. Otherwise, we grep through all the files specified. */
 479         if (argc == 0)
 480                 argc++;
 481         matched = 0;
 482         while (argc--) {
 483                 cur_file = *argv++;
 484                 file = stdin;
 485                 if (!cur_file || (*cur_file == '-' && !cur_file[1])) {
 486                         cur_file = "(standard input)";
 487                 } else {
 488                         if (option_mask32 & OPT_r) {
 489                                 struct stat st;
 490                                 if (stat(cur_file, &st) == 0 && S_ISDIR(st.st_mode)) {
 491                                         if (!(option_mask32 & OPT_h))
 492                                                 print_filename = 1;
 493                                         matched += grep_dir(cur_file);
 494                                         goto grep_done;
 495                                 }
 496                         }
 497                         /* else: fopen(dir) will succeed, but reading won't */
 498                         file = fopen(cur_file, "r");
 499                         if (file == NULL) {
 500                                 if (!SUPPRESS_ERR_MSGS)
 501                                         bb_perror_msg("%s", cur_file);
 502                                 open_errors = 1;
 503                                 continue;
 504                         }
 505                 }
 506                 matched += grep_file(file);
 507                 fclose_if_not_stdin(file);
 508  grep_done: ;
 509         }
 510
 511         /* destroy all the elments in the pattern list */
 512         if (ENABLE_FEATURE_CLEAN_UP) {
 513                 while (pattern_head) {
 514                         llist_t *pattern_head_ptr = pattern_head;
 515                         grep_list_data_t *gl =
 516                                 (grep_list_data_t *)pattern_head_ptr->data;
 517
 518                         pattern_head = pattern_head->link;
 519                         if ((gl->flg_mem_alocated_compiled & PATTERN_MEM_A))
 520                                 free(gl->pattern);
 521                         if ((gl->flg_mem_alocated_compiled & COMPILED))
 522                                 regfree(&(gl->preg));
 523                         free(gl);
 524                         free(pattern_head_ptr);
 525                 }
 526         }
 527         /* 0 = success, 1 = failed, 2 = error */
 528         if (open_errors)
 529                 return 2;
 530         return !matched; /* invert return value 0 = success, 1 = failed */
 531 }