1/* 2 * Mini grep implementation for busybox using libc regex. 3 * 4 * Copyright (C) 1999,2000,2001 by Lineo, inc. 5 * Written by Mark Whitley <markw@lineo.com>, <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 32extern int optind; /* in unistd.h */ 33extern int errno; /* for use with strerror() */ 34extern void xregcomp(regex_t *preg, const char *regex, int cflags); /* in busybox.h */ 35 36/* options */ 37static int reflags = REG_NOSUB; 38static int print_filename = 0; 39static int print_line_num = 0; 40static int print_match_counts = 0; 41static int be_quiet = 0; 42static int invert_search = 0; 43static int suppress_err_msgs = 0; 44static int print_files_with_matches = 0; 45 46#ifdef BB_FEATURE_GREP_CONTEXT 47extern char *optarg; /* in getopt.h */ 48static int lines_before = 0; 49static int lines_after = 0; 50static char **before_buf = NULL; 51static int last_line_printed = 0; 52#endif /* BB_FEATURE_GREP_CONTEXT */ 53 54/* globals used internally */ 55static regex_t *regexes = NULL; /* growable array of compiled regular expressions */ 56static int nregexes = 0; /* number of elements in above arrary */ 57static int matched; /* keeps track of whether we ever matched */ 58static char *cur_file = NULL; /* the current file we are reading */ 59 60 61static void print_line(const char *line, int linenum, char decoration) 62{ 63#ifdef BB_FEATURE_GREP_CONTEXT 64 /* possibly print the little '--' seperator */ 65 if ((lines_before || lines_after) && last_line_printed && 66 last_line_printed < linenum - 1) { 67 puts("--"); 68 } 69 last_line_printed = linenum; 70#endif 71 if (print_filename) 72 printf("%s%c", cur_file, decoration); 73 if (print_line_num) 74 printf("%i%c", linenum, decoration); 75 puts(line); 76} 77 78 79static void grep_file(FILE *file) 80{ 81 char *line = NULL; 82 int ret; 83 int linenum = 0; 84 int nmatches = 0; 85 int i; 86#ifdef BB_FEATURE_GREP_CONTEXT 87 int print_n_lines_after = 0; 88 int curpos = 0; /* track where we are in the circular 'before' buffer */ 89 int idx = 0; /* used for iteration through the circular buffer */ 90#endif /* BB_FEATURE_GREP_CONTEXT */ 91 92 while ((line = get_line_from_file(file)) != NULL) { 93 chomp(line); 94 linenum++; 95 96 for (i = 0; i < nregexes; i++) { 97 /* 98 * test for a postitive-assertion match (regexec returns success (0) 99 * and the user did not specify invert search), or a negative-assertion 100 * match (regexec returns failure (REG_NOMATCH) and the user specified 101 * invert search) 102 */ 103 ret = regexec(®exes[i], line, 0, NULL, 0); 104 if ((ret == 0 && !invert_search) || (ret == REG_NOMATCH && invert_search)) { 105 106 /* if we found a match but were told to be quiet, stop here and 107 * return success */ 108 if (be_quiet) 109 exit(0); 110 111 /* keep track of matches */ 112 nmatches++; 113 114 /* if we're just printing filenames, we stop after the first match */ 115 if (print_files_with_matches) 116 break; 117 118 /* print the matched line */ 119 if (print_match_counts == 0) { 120#ifdef BB_FEATURE_GREP_CONTEXT 121 int prevpos = (curpos == 0) ? lines_before - 1 : curpos - 1; 122 123 /* if we were told to print 'before' lines and there is at least 124 * one line in the circular buffer, print them */ 125 if (lines_before && before_buf[prevpos] != NULL) { 126 int first_buf_entry_line_num = linenum - lines_before; 127 128 /* advance to the first entry in the circular buffer, and 129 * figure out the line number is of the first line in the 130 * buffer */ 131 idx = curpos; 132 while (before_buf[idx] == NULL) { 133 idx = (idx + 1) % lines_before; 134 first_buf_entry_line_num++; 135 } 136 137 /* now print each line in the buffer, clearing them as we go */ 138 while (before_buf[idx] != NULL) { 139 print_line(before_buf[idx], first_buf_entry_line_num, '-'); 140 free(before_buf[idx]); 141 before_buf[idx] = NULL; 142 idx = (idx + 1) % lines_before; 143 first_buf_entry_line_num++; 144 } 145 } 146 147 /* make a note that we need to print 'after' lines */ 148 print_n_lines_after = lines_after; 149#endif /* BB_FEATURE_GREP_CONTEXT */ 150 print_line(line, linenum, ':'); 151 } 152 } 153#ifdef BB_FEATURE_GREP_CONTEXT 154 else { /* no match */ 155 /* Add the line to the circular 'before' buffer */ 156 if(lines_before) { 157 if(before_buf[curpos]) 158 free(before_buf[curpos]); 159 before_buf[curpos] = strdup(line); 160 curpos = (curpos + 1) % lines_before; 161 } 162 } 163 164 /* if we need to print some context lines after the last match, do so */ 165 if (print_n_lines_after && (last_line_printed != linenum)) { 166 print_line(line, linenum, '-'); 167 print_n_lines_after--; 168 } 169#endif /* BB_FEATURE_GREP_CONTEXT */ 170 } /* for */ 171 free(line); 172 } 173 174 175 /* special-case file post-processing for options where we don't print line 176 * matches, just filenames and possibly match counts */ 177 178 /* grep -c: print [filename:]count, even if count is zero */ 179 if (print_match_counts) { 180 if (print_filename) 181 printf("%s:", cur_file); 182 if (print_files_with_matches && nmatches > 0) 183 printf("1\n"); 184 else 185 printf("%d\n", nmatches); 186 } 187 188 /* grep -l: print just the filename, but only if we grepped the line in the file */ 189 if (print_files_with_matches && nmatches > 0) { 190 puts(cur_file); 191 } 192 193 194 /* remember if we matched */ 195 if (nmatches != 0) 196 matched = 1; 197} 198 199 200static void add_regex(const char *restr) 201{ 202 regexes = xrealloc(regexes, sizeof(regex_t) * (++nregexes)); 203 xregcomp(®exes[nregexes-1], restr, reflags); 204} 205 206 207static void load_regexes_from_file(const char *filename) 208{ 209 char *line; 210 FILE *f = xfopen(filename, "r"); 211 while ((line = get_line_from_file(f)) != NULL) { 212 chomp(line); 213 add_regex(line); 214 free(line); 215 } 216} 217 218 219#ifdef BB_FEATURE_CLEAN_UP 220static void destroy_regexes() 221{ 222 if (regexes == NULL) 223 return; 224 225 /* destroy all the elments in the array */ 226 while (--nregexes >= 0) { 227 regfree(®exes[nregexes]); 228 free(®exes[nregexes]); 229 } 230} 231#endif 232 233 234extern int grep_main(int argc, char **argv) 235{ 236 int opt; 237#ifdef BB_FEATURE_GREP_CONTEXT 238 char *junk; 239#endif 240 241#ifdef BB_FEATURE_CLEAN_UP 242 /* destroy command strings on exit */ 243 if (atexit(destroy_regexes) == -1) 244 perror_msg_and_die("atexit"); 245#endif 246 247 /* do normal option parsing */ 248 while ((opt = getopt(argc, argv, "iHhlnqvsce:f:" 249#ifdef BB_FEATURE_GREP_CONTEXT 250"A:B:C:" 251#endif 252)) > 0) { 253 switch (opt) { 254 case 'i': 255 reflags |= REG_ICASE; 256 break; 257 case 'l': 258 print_files_with_matches++; 259 break; 260 case 'H': 261 print_filename++; 262 break; 263 case 'h': 264 print_filename--; 265 break; 266 case 'n': 267 print_line_num++; 268 break; 269 case 'q': 270 be_quiet++; 271 break; 272 case 'v': 273 invert_search++; 274 break; 275 case 's': 276 suppress_err_msgs++; 277 break; 278 case 'c': 279 print_match_counts++; 280 break; 281 case 'e': 282 add_regex(optarg); 283 break; 284 case 'f': 285 load_regexes_from_file(optarg); 286 break; 287#ifdef BB_FEATURE_GREP_CONTEXT 288 case 'A': 289 lines_after = strtoul(optarg, &junk, 10); 290 if(*junk != '\0') 291 error_msg_and_die("invalid context length argument"); 292 break; 293 case 'B': 294 lines_before = strtoul(optarg, &junk, 10); 295 if(*junk != '\0') 296 error_msg_and_die("invalid context length argument"); 297 before_buf = (char **)calloc(lines_before, sizeof(char *)); 298 break; 299 case 'C': 300 lines_after = lines_before = strtoul(optarg, &junk, 10); 301 if(*junk != '\0') 302 error_msg_and_die("invalid context length argument"); 303 before_buf = (char **)calloc(lines_before, sizeof(char *)); 304 break; 305#endif /* BB_FEATURE_GREP_CONTEXT */ 306 default: 307 show_usage(); 308 } 309 } 310 311 /* if we didn't get a pattern from a -e and no command file was specified, 312 * argv[optind] should be the pattern. no pattern, no worky */ 313 if (nregexes == 0) { 314 if (argv[optind] == NULL) 315 show_usage(); 316 else { 317 add_regex(argv[optind]); 318 optind++; 319 } 320 } 321 322 /* sanity checks */ 323 if (print_match_counts || be_quiet || print_files_with_matches) { 324 print_line_num = 0; 325#ifdef BB_FEATURE_GREP_CONTEXT 326 lines_before = 0; 327 lines_after = 0; 328#endif 329 } 330 331 /* argv[(optind)..(argc-1)] should be names of file to grep through. If 332 * there is more than one file to grep, we will print the filenames */ 333 if ((argc-1) - (optind) > 0) 334 print_filename++; 335 336 /* If no files were specified, or '-' was specified, take input from 337 * stdin. Otherwise, we grep through all the files specified. */ 338 if (argv[optind] == NULL || (strcmp(argv[optind], "-") == 0)) { 339 grep_file(stdin); 340 } 341 else { 342 int i; 343 FILE *file; 344 for (i = optind; i < argc; i++) { 345 cur_file = argv[i]; 346 file = fopen(cur_file, "r"); 347 if (file == NULL) { 348 if (!suppress_err_msgs) 349 perror_msg("%s", cur_file); 350 } 351 else { 352 grep_file(file); 353 fclose(file); 354 } 355 } 356 } 357 358 return !matched; /* invert return value 0 = success, 1 = failed */ 359} 360