findutils/grep.c

   1 /*
   2  * Mini grep implementation for busybox using libc regex.
   3  *
   4  * Copyright (C) 1999,2000,2001 by Lineo, inc. and Mark Whitley
   5  * Copyright (C) 1999,2000,2001 by Mark Whitley <markw@codepoet.org>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  *
  21  */
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <getopt.h>
  26 #include <regex.h>
  27 #include <string.h> /* for strerror() */
  28 #include <errno.h>
  29 #include "busybox.h"
  30
  31
  32 extern int optind; /* in unistd.h */
  33 extern void xregcomp(regex_t *preg, const char *regex, int cflags); /* in busybox.h */
  34
  35 /* options */
  36 static int reflags            = REG_NOSUB;
  37 static int print_filename     = 0;
  38 static int print_line_num     = 0;
  39 static int print_match_counts = 0;
  40 static int be_quiet           = 0;
  41 static int invert_search      = 0;
  42 static int suppress_err_msgs  = 0;
  43 static int print_files_with_matches  = 0;
  44 static int fgrep_flag            = 0;
  45
  46 #ifdef CONFIG_FEATURE_GREP_CONTEXT
  47 extern char *optarg; /* in getopt.h */
  48 static int lines_before      = 0;
  49 static int lines_after       = 0;
  50 static char **before_buf     = NULL;
  51 static int last_line_printed = 0;
  52 #endif /* CONFIG_FEATURE_GREP_CONTEXT */
  53
  54 /* globals used internally */
  55 static llist_t *pattern_head = NULL; /* growable list of patterns to match */
  56 static int matched; /* keeps track of whether we ever matched */
  57 static char *cur_file = NULL; /* the current file we are reading */
  58
  59
  60 static void print_line(const char *line, int linenum, char decoration)
  61 {
  62 #ifdef CONFIG_FEATURE_GREP_CONTEXT
  63         /* possibly print the little '--' seperator */
  64         if ((lines_before || lines_after) && last_line_printed &&
  65                         last_line_printed < linenum - 1) {
  66                 puts("--");
  67         }
  68         last_line_printed = linenum;
  69 #endif
  70         if (print_filename)
  71                 printf("%s%c", cur_file, decoration);
  72         if (print_line_num)
  73                 printf("%i%c", linenum, decoration);
  74         puts(line);
  75 }
  76
  77
  78 static void grep_file(FILE *file)
  79 {
  80         char *line = NULL;
  81         int ret;
  82         int linenum = 0;
  83         int nmatches = 0;
  84 #ifdef CONFIG_FEATURE_GREP_CONTEXT
  85         int print_n_lines_after = 0;
  86         int curpos = 0; /* track where we are in the circular 'before' buffer */
  87         int idx = 0; /* used for iteration through the circular buffer */
  88 #endif /* CONFIG_FEATURE_GREP_CONTEXT */
  89
  90         while ((line = bb_get_chomped_line_from_file(file)) != NULL) {
  91                 llist_t *pattern_ptr = pattern_head;
  92
  93                 linenum++;
  94
  95                 while (pattern_ptr) {
  96                         if (fgrep_flag) {
  97                                 if (strstr(line, pattern_ptr->data)) {
  98                                         /* Match found */
  99                                         ret = 0;
 100                                 } else {
 101                                         ret = 1;
 102                                 }
 103                         } else {
 104                                 /*
 105                                  * test for a postitive-assertion match (regexec returns success (0)
 106                                  * and the user did not specify invert search), or a negative-assertion
 107                                  * match (regexec returns failure (REG_NOMATCH) and the user specified
 108                                  * invert search)
 109                                  */
 110                                 regex_t regex;
 111                                 xregcomp(&regex, pattern_ptr->data, reflags);
 112                                 ret = regexec(&regex, line, 0, NULL, 0);
 113                                 regfree(&regex);
 114                         }
 115                         if ((ret == 0 && !invert_search) || (ret == REG_NOMATCH && invert_search)) {
 116
 117                                 /* if we found a match but were told to be quiet, stop here and
 118                                  * return success */
 119                                 if (be_quiet)
 120                                         exit(0);
 121
 122                                 /* keep track of matches */
 123                                 nmatches++;
 124
 125                                 /* if we're just printing filenames, we stop after the first match */
 126                                 if (print_files_with_matches)
 127                                         break;
 128
 129                                 /* print the matched line */
 130                                 if (print_match_counts == 0) {
 131 #ifdef CONFIG_FEATURE_GREP_CONTEXT
 132                                         int prevpos = (curpos == 0) ? lines_before - 1 : curpos - 1;
 133
 134                                         /* if we were told to print 'before' lines and there is at least
 135                                          * one line in the circular buffer, print them */
 136                                         if (lines_before && before_buf[prevpos] != NULL) {
 137                                                 int first_buf_entry_line_num = linenum - lines_before;
 138
 139                                                 /* advance to the first entry in the circular buffer, and
 140                                                  * figure out the line number is of the first line in the
 141                                                  * buffer */
 142                                                 idx = curpos;
 143                                                 while (before_buf[idx] == NULL) {
 144                                                         idx = (idx + 1) % lines_before;
 145                                                         first_buf_entry_line_num++;
 146                                                 }
 147
 148                                                 /* now print each line in the buffer, clearing them as we go */
 149                                                 while (before_buf[idx] != NULL) {
 150                                                         print_line(before_buf[idx], first_buf_entry_line_num, '-');
 151                                                         free(before_buf[idx]);
 152                                                         before_buf[idx] = NULL;
 153                                                         idx = (idx + 1) % lines_before;
 154                                                         first_buf_entry_line_num++;
 155                                                 }
 156                                         }
 157
 158                                         /* make a note that we need to print 'after' lines */
 159                                         print_n_lines_after = lines_after;
 160 #endif /* CONFIG_FEATURE_GREP_CONTEXT */
 161                                         print_line(line, linenum, ':');
 162                                 }
 163                         }
 164 #ifdef CONFIG_FEATURE_GREP_CONTEXT
 165                         else { /* no match */
 166                                 /* Add the line to the circular 'before' buffer */
 167                                 if(lines_before) {
 168                                         free(before_buf[curpos]);
 169                                         before_buf[curpos] = bb_xstrdup(line);
 170                                         curpos = (curpos + 1) % lines_before;
 171                                 }
 172                         }
 173
 174                         /* if we need to print some context lines after the last match, do so */
 175                         if (print_n_lines_after && (last_line_printed != linenum)) {
 176                                 print_line(line, linenum, '-');
 177                                 print_n_lines_after--;
 178                         }
 179 #endif /* CONFIG_FEATURE_GREP_CONTEXT */
 180                         pattern_ptr = pattern_ptr->link;
 181                 } /* for */
 182                 free(line);
 183         }
 184
 185
 186         /* special-case file post-processing for options where we don't print line
 187          * matches, just filenames and possibly match counts */
 188
 189         /* grep -c: print [filename:]count, even if count is zero */
 190         if (print_match_counts) {
 191                 if (print_filename)
 192                         printf("%s:", cur_file);
 193                 if (print_files_with_matches && nmatches > 0)
 194                         printf("1\n");
 195                 else
 196                     printf("%d\n", nmatches);
 197         }
 198
 199         /* grep -l: print just the filename, but only if we grepped the line in the file  */
 200         if (print_files_with_matches && nmatches > 0) {
 201                 puts(cur_file);
 202         }
 203
 204
 205         /* remember if we matched */
 206         if (nmatches != 0)
 207                 matched = 1;
 208 }
 209
 210 #if 0
 211 static void add_pattern(char *restr)
 212 {
 213 //      regexes = xrealloc(regexes, sizeof(regex_t) * (++nregexes));
 214 //      xregcomp(&regexes[nregexes-1], restr, reflags);
 215         pattern_head = llist_add_to(pattern_head, restr);
 216 }
 217 #endif
 218
 219 static void     load_regexes_from_file(const char *filename)
 220 {
 221         char *line;
 222         FILE *f = bb_xfopen(filename, "r");
 223         while ((line = bb_get_chomped_line_from_file(f)) != NULL) {
 224                 pattern_head = llist_add_to(pattern_head, line);
 225         }
 226 }
 227
 228
 229 #ifdef CONFIG_FEATURE_CLEAN_UP
 230 static void destroy_regexes(void)
 231 {
 232         llist_t *pattern_head_ptr;
 233
 234         if (pattern_head == NULL)
 235                 return;
 236
 237         /* destroy all the elments in the pattern list */
 238         while (pattern_head) {
 239                 pattern_head_ptr = pattern_head;
 240                 pattern_head = pattern_head->link;
 241                 free(pattern_head_ptr->data);
 242                 free(pattern_head_ptr);
 243         }
 244 }
 245 #endif
 246
 247
 248 extern int grep_main(int argc, char **argv)
 249 {
 250         int opt;
 251 #if defined (CONFIG_FEATURE_GREP_CONTEXT)
 252         char *junk;
 253 #endif
 254
 255 #ifdef CONFIG_FEATURE_CLEAN_UP
 256         /* destroy command strings on exit */
 257         atexit(destroy_regexes);
 258 #endif
 259
 260 #ifdef CONFIG_FEATURE_GREP_EGREP_ALIAS
 261         if (strcmp(bb_get_last_path_component(argv[0]), "egrep") == 0)
 262                 reflags |= REG_EXTENDED;
 263 #endif
 264
 265         /* do normal option parsing */
 266         while ((opt = getopt(argc, argv, "iHhlnqvsce:f:F"
 267 #ifdef CONFIG_FEATURE_GREP_CONTEXT
 268 "A:B:C:"
 269 #endif
 270 #ifdef CONFIG_FEATURE_GREP_EGREP_ALIAS
 271 "E"
 272 #endif
 273 )) > 0) {
 274                 switch (opt) {
 275                         case 'i':
 276                                 reflags |= REG_ICASE;
 277                                 break;
 278                         case 'l':
 279                                 print_files_with_matches++;
 280                                 break;
 281                         case 'H':
 282                                 print_filename++;
 283                                 break;
 284                         case 'h':
 285                                 print_filename--;
 286                                 break;
 287                         case 'n':
 288                                 print_line_num++;
 289                                 break;
 290                         case 'q':
 291                                 be_quiet++;
 292                                 break;
 293                         case 'v':
 294                                 invert_search++;
 295                                 break;
 296                         case 's':
 297                                 suppress_err_msgs++;
 298                                 break;
 299                         case 'c':
 300                                 print_match_counts++;
 301                                 break;
 302                         case 'e':
 303                                 pattern_head = llist_add_to(pattern_head, strdup(optarg));
 304                                 break;
 305 #ifdef CONFIG_FEATURE_GREP_EGREP_ALIAS
 306                         case 'E':
 307                                 reflags |= REG_EXTENDED;
 308                                 break;
 309 #endif
 310                         case 'F':
 311                                 fgrep_flag = 1;
 312                                 break;
 313                         case 'f':
 314                                 load_regexes_from_file(optarg);
 315                                 break;
 316 #ifdef CONFIG_FEATURE_GREP_CONTEXT
 317                         case 'A':
 318                                 lines_after = strtoul(optarg, &junk, 10);
 319                                 if(*junk != '\0')
 320                                         bb_error_msg_and_die("invalid context length argument");
 321                                 break;
 322                         case 'B':
 323                                 lines_before = strtoul(optarg, &junk, 10);
 324                                 if(*junk != '\0')
 325                                         bb_error_msg_and_die("invalid context length argument");
 326                                 before_buf = (char **)xcalloc(lines_before, sizeof(char *));
 327                                 break;
 328                         case 'C':
 329                                 lines_after = lines_before = strtoul(optarg, &junk, 10);
 330                                 if(*junk != '\0')
 331                                         bb_error_msg_and_die("invalid context length argument");
 332                                 before_buf = (char **)xcalloc(lines_before, sizeof(char *));
 333                                 break;
 334 #endif /* CONFIG_FEATURE_GREP_CONTEXT */
 335                         default:
 336                                 bb_show_usage();
 337                 }
 338         }
 339
 340         /* if we didn't get a pattern from a -e and no command file was specified,
 341          * argv[optind] should be the pattern. no pattern, no worky */
 342         if (pattern_head == NULL) {
 343                 if (argv[optind] == NULL)
 344                         bb_show_usage();
 345                 else {
 346                         pattern_head = llist_add_to(pattern_head, strdup(argv[optind]));
 347                         optind++;
 348                 }
 349         }
 350
 351         /* sanity checks */
 352         if (print_match_counts || be_quiet || print_files_with_matches) {
 353                 print_line_num = 0;
 354 #ifdef CONFIG_FEATURE_GREP_CONTEXT
 355                 lines_before = 0;
 356                 lines_after = 0;
 357 #endif
 358         }
 359
 360         /* argv[(optind)..(argc-1)] should be names of file to grep through. If
 361          * there is more than one file to grep, we will print the filenames */
 362         if ((argc-1) - (optind) > 0)
 363                 print_filename++;
 364
 365         /* If no files were specified, or '-' was specified, take input from
 366          * stdin. Otherwise, we grep through all the files specified. */
 367         if (argv[optind] == NULL || (strcmp(argv[optind], "-") == 0)) {
 368                 grep_file(stdin);
 369         }
 370         else {
 371                 int i;
 372                 FILE *file;
 373                 for (i = optind; i < argc; i++) {
 374                         cur_file = argv[i];
 375                         file = fopen(cur_file, "r");
 376                         if (file == NULL) {
 377                                 if (!suppress_err_msgs)
 378                                         bb_perror_msg("%s", cur_file);
 379                         }
 380                         else {
 381                                 grep_file(file);
 382                                 fclose(file);
 383                         }
 384                 }
 385         }
 386
 387         return !matched; /* invert return value 0 = success, 1 = failed */
 388 }