builtin-grep.c

   1 /*
   2  * Builtin "git grep"
   3  *
   4  * Copyright (c) 2006 Junio C Hamano
   5  */
   6 #include "cache.h"
   7 #include "blob.h"
   8 #include "tree.h"
   9 #include "commit.h"
  10 #include "tag.h"
  11 #include "tree-walk.h"
  12 #include "builtin.h"
  13 #include "parse-options.h"
  14 #include "userdiff.h"
  15 #include "grep.h"
  16 #include "quote.h"
  17
  18 #ifndef NO_EXTERNAL_GREP
  19 #ifdef __unix__
  20 #define NO_EXTERNAL_GREP 0
  21 #else
  22 #define NO_EXTERNAL_GREP 1
  23 #endif
  24 #endif
  25
  26 static char const * const grep_usage[] = {
  27         "git grep [options] [-e] <pattern> [<rev>...] [[--] path...]",
  28         NULL
  29 };
  30
  31 static int grep_config(const char *var, const char *value, void *cb)
  32 {
  33         struct grep_opt *opt = cb;
  34
  35         switch (userdiff_config(var, value)) {
  36         case 0: break;
  37         case -1: return -1;
  38         default: return 0;
  39         }
  40
  41         if (!strcmp(var, "color.grep")) {
  42                 opt->color = git_config_colorbool(var, value, -1);
  43                 return 0;
  44         }
  45         if (!strcmp(var, "color.grep.external"))
  46                 return git_config_string(&(opt->color_external), var, value);
  47         if (!strcmp(var, "color.grep.match")) {
  48                 if (!value)
  49                         return config_error_nonbool(var);
  50                 color_parse(value, var, opt->color_match);
  51                 return 0;
  52         }
  53         return git_color_default_config(var, value, cb);
  54 }
  55
  56 /*
  57  * git grep pathspecs are somewhat different from diff-tree pathspecs;
  58  * pathname wildcards are allowed.
  59  */
  60 static int pathspec_matches(const char **paths, const char *name)
  61 {
  62         int namelen, i;
  63         if (!paths || !*paths)
  64                 return 1;
  65         namelen = strlen(name);
  66         for (i = 0; paths[i]; i++) {
  67                 const char *match = paths[i];
  68                 int matchlen = strlen(match);
  69                 const char *cp, *meta;
  70
  71                 if (!matchlen ||
  72                     ((matchlen <= namelen) &&
  73                      !strncmp(name, match, matchlen) &&
  74                      (match[matchlen-1] == '/' ||
  75                       name[matchlen] == '\0' || name[matchlen] == '/')))
  76                         return 1;
  77                 if (!fnmatch(match, name, 0))
  78                         return 1;
  79                 if (name[namelen-1] != '/')
  80                         continue;
  81
  82                 /* We are being asked if the directory ("name") is worth
  83                  * descending into.
  84                  *
  85                  * Find the longest leading directory name that does
  86                  * not have metacharacter in the pathspec; the name
  87                  * we are looking at must overlap with that directory.
  88                  */
  89                 for (cp = match, meta = NULL; cp - match < matchlen; cp++) {
  90                         char ch = *cp;
  91                         if (ch == '*' || ch == '[' || ch == '?') {
  92                                 meta = cp;
  93                                 break;
  94                         }
  95                 }
  96                 if (!meta)
  97                         meta = cp; /* fully literal */
  98
  99                 if (namelen <= meta - match) {
 100                         /* Looking at "Documentation/" and
 101                          * the pattern says "Documentation/howto/", or
 102                          * "Documentation/diff*.txt".  The name we
 103                          * have should match prefix.
 104                          */
 105                         if (!memcmp(match, name, namelen))
 106                                 return 1;
 107                         continue;
 108                 }
 109
 110                 if (meta - match < namelen) {
 111                         /* Looking at "Documentation/howto/" and
 112                          * the pattern says "Documentation/h*";
 113                          * match up to "Do.../h"; this avoids descending
 114                          * into "Documentation/technical/".
 115                          */
 116                         if (!memcmp(match, name, meta - match))
 117                                 return 1;
 118                         continue;
 119                 }
 120         }
 121         return 0;
 122 }
 123
 124 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name, int tree_name_len)
 125 {
 126         unsigned long size;
 127         char *data;
 128         enum object_type type;
 129         int hit;
 130         struct strbuf pathbuf = STRBUF_INIT;
 131
 132         data = read_sha1_file(sha1, &type, &size);
 133         if (!data) {
 134                 error("'%s': unable to read %s", name, sha1_to_hex(sha1));
 135                 return 0;
 136         }
 137         if (opt->relative && opt->prefix_length) {
 138                 quote_path_relative(name + tree_name_len, -1, &pathbuf, opt->prefix);
 139                 strbuf_insert(&pathbuf, 0, name, tree_name_len);
 140                 name = pathbuf.buf;
 141         }
 142         hit = grep_buffer(opt, name, data, size);
 143         strbuf_release(&pathbuf);
 144         free(data);
 145         return hit;
 146 }
 147
 148 static int grep_file(struct grep_opt *opt, const char *filename)
 149 {
 150         struct stat st;
 151         int i;
 152         char *data;
 153         size_t sz;
 154         struct strbuf buf = STRBUF_INIT;
 155
 156         if (lstat(filename, &st) < 0) {
 157         err_ret:
 158                 if (errno != ENOENT)
 159                         error("'%s': %s", filename, strerror(errno));
 160                 return 0;
 161         }
 162         if (!st.st_size)
 163                 return 0; /* empty file -- no grep hit */
 164         if (!S_ISREG(st.st_mode))
 165                 return 0;
 166         sz = xsize_t(st.st_size);
 167         i = open(filename, O_RDONLY);
 168         if (i < 0)
 169                 goto err_ret;
 170         data = xmalloc(sz + 1);
 171         if (st.st_size != read_in_full(i, data, sz)) {
 172                 error("'%s': short read %s", filename, strerror(errno));
 173                 close(i);
 174                 free(data);
 175                 return 0;
 176         }
 177         close(i);
 178         if (opt->relative && opt->prefix_length)
 179                 filename = quote_path_relative(filename, -1, &buf, opt->prefix);
 180         i = grep_buffer(opt, filename, data, sz);
 181         strbuf_release(&buf);
 182         free(data);
 183         return i;
 184 }
 185
 186 #if !NO_EXTERNAL_GREP
 187 static int exec_grep(int argc, const char **argv)
 188 {
 189         pid_t pid;
 190         int status;
 191
 192         argv[argc] = NULL;
 193         pid = fork();
 194         if (pid < 0)
 195                 return pid;
 196         if (!pid) {
 197                 execvp("grep", (char **) argv);
 198                 exit(255);
 199         }
 200         while (waitpid(pid, &status, 0) < 0) {
 201                 if (errno == EINTR)
 202                         continue;
 203                 return -1;
 204         }
 205         if (WIFEXITED(status)) {
 206                 if (!WEXITSTATUS(status))
 207                         return 1;
 208                 return 0;
 209         }
 210         return -1;
 211 }
 212
 213 #define MAXARGS 1000
 214 #define ARGBUF 4096
 215 #define push_arg(a) do { \
 216         if (nr < MAXARGS) argv[nr++] = (a); \
 217         else die("maximum number of args exceeded"); \
 218         } while (0)
 219
 220 /*
 221  * If you send a singleton filename to grep, it does not give
 222  * the name of the file.  GNU grep has "-H" but we would want
 223  * that behaviour in a portable way.
 224  *
 225  * So we keep two pathnames in argv buffer unsent to grep in
 226  * the main loop if we need to do more than one grep.
 227  */
 228 static int flush_grep(struct grep_opt *opt,
 229                       int argc, int arg0, const char **argv, int *kept)
 230 {
 231         int status;
 232         int count = argc - arg0;
 233         const char *kept_0 = NULL;
 234
 235         if (count <= 2) {
 236                 /*
 237                  * Because we keep at least 2 paths in the call from
 238                  * the main loop (i.e. kept != NULL), and MAXARGS is
 239                  * far greater than 2, this usually is a call to
 240                  * conclude the grep.  However, the user could attempt
 241                  * to overflow the argv buffer by giving too many
 242                  * options to leave very small number of real
 243                  * arguments even for the call in the main loop.
 244                  */
 245                 if (kept)
 246                         die("insanely many options to grep");
 247
 248                 /*
 249                  * If we have two or more paths, we do not have to do
 250                  * anything special, but we need to push /dev/null to
 251                  * get "-H" behaviour of GNU grep portably but when we
 252                  * are not doing "-l" nor "-L" nor "-c".
 253                  */
 254                 if (count == 1 &&
 255                     !opt->name_only &&
 256                     !opt->unmatch_name_only &&
 257                     !opt->count) {
 258                         argv[argc++] = "/dev/null";
 259                         argv[argc] = NULL;
 260                 }
 261         }
 262
 263         else if (kept) {
 264                 /*
 265                  * Called because we found many paths and haven't finished
 266                  * iterating over the cache yet.  We keep two paths
 267                  * for the concluding call.  argv[argc-2] and argv[argc-1]
 268                  * has the last two paths, so save the first one away,
 269                  * replace it with NULL while sending the list to grep,
 270                  * and recover them after we are done.
 271                  */
 272                 *kept = 2;
 273                 kept_0 = argv[argc-2];
 274                 argv[argc-2] = NULL;
 275                 argc -= 2;
 276         }
 277
 278         if (opt->pre_context || opt->post_context) {
 279                 /*
 280                  * grep handles hunk marks between files, but we need to
 281                  * do that ourselves between multiple calls.
 282                  */
 283                 if (opt->show_hunk_mark)
 284                         write_or_die(1, "--\n", 3);
 285                 else
 286                         opt->show_hunk_mark = 1;
 287         }
 288
 289         status = exec_grep(argc, argv);
 290
 291         if (kept_0) {
 292                 /*
 293                  * Then recover them.  Now the last arg is beyond the
 294                  * terminating NULL which is at argc, and the second
 295                  * from the last is what we saved away in kept_0
 296                  */
 297                 argv[arg0++] = kept_0;
 298                 argv[arg0] = argv[argc+1];
 299         }
 300         return status;
 301 }
 302
 303 static void grep_add_color(struct strbuf *sb, const char *escape_seq)
 304 {
 305         size_t orig_len = sb->len;
 306
 307         while (*escape_seq) {
 308                 if (*escape_seq == 'm')
 309                         strbuf_addch(sb, ';');
 310                 else if (*escape_seq != '\033' && *escape_seq  != '[')
 311                         strbuf_addch(sb, *escape_seq);
 312                 escape_seq++;
 313         }
 314         if (sb->len > orig_len && sb->buf[sb->len - 1] == ';')
 315                 strbuf_setlen(sb, sb->len - 1);
 316 }
 317
 318 static int external_grep(struct grep_opt *opt, const char **paths, int cached)
 319 {
 320         int i, nr, argc, hit, len, status;
 321         const char *argv[MAXARGS+1];
 322         char randarg[ARGBUF];
 323         char *argptr = randarg;
 324         struct grep_pat *p;
 325
 326         if (opt->extended || (opt->relative && opt->prefix_length))
 327                 return -1;
 328         len = nr = 0;
 329         push_arg("grep");
 330         if (opt->fixed)
 331                 push_arg("-F");
 332         if (opt->linenum)
 333                 push_arg("-n");
 334         if (!opt->pathname)
 335                 push_arg("-h");
 336         if (opt->regflags & REG_EXTENDED)
 337                 push_arg("-E");
 338         if (opt->regflags & REG_ICASE)
 339                 push_arg("-i");
 340         if (opt->binary == GREP_BINARY_NOMATCH)
 341                 push_arg("-I");
 342         if (opt->word_regexp)
 343                 push_arg("-w");
 344         if (opt->name_only)
 345                 push_arg("-l");
 346         if (opt->unmatch_name_only)
 347                 push_arg("-L");
 348         if (opt->null_following_name)
 349                 /* in GNU grep git's "-z" translates to "-Z" */
 350                 push_arg("-Z");
 351         if (opt->count)
 352                 push_arg("-c");
 353         if (opt->post_context || opt->pre_context) {
 354                 if (opt->post_context != opt->pre_context) {
 355                         if (opt->pre_context) {
 356                                 push_arg("-B");
 357                                 len += snprintf(argptr, sizeof(randarg)-len,
 358                                                 "%u", opt->pre_context) + 1;
 359                                 if (sizeof(randarg) <= len)
 360                                         die("maximum length of args exceeded");
 361                                 push_arg(argptr);
 362                                 argptr += len;
 363                         }
 364                         if (opt->post_context) {
 365                                 push_arg("-A");
 366                                 len += snprintf(argptr, sizeof(randarg)-len,
 367                                                 "%u", opt->post_context) + 1;
 368                                 if (sizeof(randarg) <= len)
 369                                         die("maximum length of args exceeded");
 370                                 push_arg(argptr);
 371                                 argptr += len;
 372                         }
 373                 }
 374                 else {
 375                         push_arg("-C");
 376                         len += snprintf(argptr, sizeof(randarg)-len,
 377                                         "%u", opt->post_context) + 1;
 378                         if (sizeof(randarg) <= len)
 379                                 die("maximum length of args exceeded");
 380                         push_arg(argptr);
 381                         argptr += len;
 382                 }
 383         }
 384         for (p = opt->pattern_list; p; p = p->next) {
 385                 push_arg("-e");
 386                 push_arg(p->pattern);
 387         }
 388         if (opt->color) {
 389                 struct strbuf sb = STRBUF_INIT;
 390
 391                 grep_add_color(&sb, opt->color_match);
 392                 setenv("GREP_COLOR", sb.buf, 1);
 393
 394                 strbuf_reset(&sb);
 395                 strbuf_addstr(&sb, "mt=");
 396                 grep_add_color(&sb, opt->color_match);
 397                 strbuf_addstr(&sb, ":sl=:cx=:fn=:ln=:bn=:se=");
 398                 setenv("GREP_COLORS", sb.buf, 1);
 399
 400                 strbuf_release(&sb);
 401
 402                 if (opt->color_external && strlen(opt->color_external) > 0)
 403                         push_arg(opt->color_external);
 404         }
 405
 406         hit = 0;
 407         argc = nr;
 408         for (i = 0; i < active_nr; i++) {
 409                 struct cache_entry *ce = active_cache[i];
 410                 char *name;
 411                 int kept;
 412                 if (!S_ISREG(ce->ce_mode))
 413                         continue;
 414                 if (!pathspec_matches(paths, ce->name))
 415                         continue;
 416                 name = ce->name;
 417                 if (name[0] == '-') {
 418                         int len = ce_namelen(ce);
 419                         name = xmalloc(len + 3);
 420                         memcpy(name, "./", 2);
 421                         memcpy(name + 2, ce->name, len + 1);
 422                 }
 423                 argv[argc++] = name;
 424                 if (MAXARGS <= argc) {
 425                         status = flush_grep(opt, argc, nr, argv, &kept);
 426                         if (0 < status)
 427                                 hit = 1;
 428                         argc = nr + kept;
 429                 }
 430                 if (ce_stage(ce)) {
 431                         do {
 432                                 i++;
 433                         } while (i < active_nr &&
 434                                  !strcmp(ce->name, active_cache[i]->name));
 435                         i--; /* compensate for loop control */
 436                 }
 437         }
 438         if (argc > nr) {
 439                 status = flush_grep(opt, argc, nr, argv, NULL);
 440                 if (0 < status)
 441                         hit = 1;
 442         }
 443         return hit;
 444 }
 445 #endif
 446
 447 static int grep_cache(struct grep_opt *opt, const char **paths, int cached,
 448                       int external_grep_allowed)
 449 {
 450         int hit = 0;
 451         int nr;
 452         read_cache();
 453
 454 #if !NO_EXTERNAL_GREP
 455         /*
 456          * Use the external "grep" command for the case where
 457          * we grep through the checked-out files. It tends to
 458          * be a lot more optimized
 459          */
 460         if (!cached && external_grep_allowed) {
 461                 hit = external_grep(opt, paths, cached);
 462                 if (hit >= 0)
 463                         return hit;
 464                 hit = 0;
 465         }
 466 #endif
 467
 468         for (nr = 0; nr < active_nr; nr++) {
 469                 struct cache_entry *ce = active_cache[nr];
 470                 if (!S_ISREG(ce->ce_mode))
 471                         continue;
 472                 if (!pathspec_matches(paths, ce->name))
 473                         continue;
 474                 /*
 475                  * If CE_VALID is on, we assume worktree file and its cache entry
 476                  * are identical, even if worktree file has been modified, so use
 477                  * cache version instead
 478                  */
 479                 if (cached || (ce->ce_flags & CE_VALID)) {
 480                         if (ce_stage(ce))
 481                                 continue;
 482                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 483                 }
 484                 else
 485                         hit |= grep_file(opt, ce->name);
 486                 if (ce_stage(ce)) {
 487                         do {
 488                                 nr++;
 489                         } while (nr < active_nr &&
 490                                  !strcmp(ce->name, active_cache[nr]->name));
 491                         nr--; /* compensate for loop control */
 492                 }
 493         }
 494         free_grep_patterns(opt);
 495         return hit;
 496 }
 497
 498 static int grep_tree(struct grep_opt *opt, const char **paths,
 499                      struct tree_desc *tree,
 500                      const char *tree_name, const char *base)
 501 {
 502         int len;
 503         int hit = 0;
 504         struct name_entry entry;
 505         char *down;
 506         int tn_len = strlen(tree_name);
 507         struct strbuf pathbuf;
 508
 509         strbuf_init(&pathbuf, PATH_MAX + tn_len);
 510
 511         if (tn_len) {
 512                 strbuf_add(&pathbuf, tree_name, tn_len);
 513                 strbuf_addch(&pathbuf, ':');
 514                 tn_len = pathbuf.len;
 515         }
 516         strbuf_addstr(&pathbuf, base);
 517         len = pathbuf.len;
 518
 519         while (tree_entry(tree, &entry)) {
 520                 int te_len = tree_entry_len(entry.path, entry.sha1);
 521                 pathbuf.len = len;
 522                 strbuf_add(&pathbuf, entry.path, te_len);
 523
 524                 if (S_ISDIR(entry.mode))
 525                         /* Match "abc/" against pathspec to
 526                          * decide if we want to descend into "abc"
 527                          * directory.
 528                          */
 529                         strbuf_addch(&pathbuf, '/');
 530
 531                 down = pathbuf.buf + tn_len;
 532                 if (!pathspec_matches(paths, down))
 533                         ;
 534                 else if (S_ISREG(entry.mode))
 535                         hit |= grep_sha1(opt, entry.sha1, pathbuf.buf, tn_len);
 536                 else if (S_ISDIR(entry.mode)) {
 537                         enum object_type type;
 538                         struct tree_desc sub;
 539                         void *data;
 540                         unsigned long size;
 541
 542                         data = read_sha1_file(entry.sha1, &type, &size);
 543                         if (!data)
 544                                 die("unable to read tree (%s)",
 545                                     sha1_to_hex(entry.sha1));
 546                         init_tree_desc(&sub, data, size);
 547                         hit |= grep_tree(opt, paths, &sub, tree_name, down);
 548                         free(data);
 549                 }
 550         }
 551         strbuf_release(&pathbuf);
 552         return hit;
 553 }
 554
 555 static int grep_object(struct grep_opt *opt, const char **paths,
 556                        struct object *obj, const char *name)
 557 {
 558         if (obj->type == OBJ_BLOB)
 559                 return grep_sha1(opt, obj->sha1, name, 0);
 560         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 561                 struct tree_desc tree;
 562                 void *data;
 563                 unsigned long size;
 564                 int hit;
 565                 data = read_object_with_reference(obj->sha1, tree_type,
 566                                                   &size, NULL);
 567                 if (!data)
 568                         die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
 569                 init_tree_desc(&tree, data, size);
 570                 hit = grep_tree(opt, paths, &tree, name, "");
 571                 free(data);
 572                 return hit;
 573         }
 574         die("unable to grep from object of type %s", typename(obj->type));
 575 }
 576
 577 static int context_callback(const struct option *opt, const char *arg,
 578                             int unset)
 579 {
 580         struct grep_opt *grep_opt = opt->value;
 581         int value;
 582         const char *endp;
 583
 584         if (unset) {
 585                 grep_opt->pre_context = grep_opt->post_context = 0;
 586                 return 0;
 587         }
 588         value = strtol(arg, (char **)&endp, 10);
 589         if (*endp) {
 590                 return error("switch `%c' expects a numerical value",
 591                              opt->short_name);
 592         }
 593         grep_opt->pre_context = grep_opt->post_context = value;
 594         return 0;
 595 }
 596
 597 static int file_callback(const struct option *opt, const char *arg, int unset)
 598 {
 599         struct grep_opt *grep_opt = opt->value;
 600         FILE *patterns;
 601         int lno = 0;
 602         struct strbuf sb = STRBUF_INIT;
 603
 604         patterns = fopen(arg, "r");
 605         if (!patterns)
 606                 die_errno("cannot open '%s'", arg);
 607         while (strbuf_getline(&sb, patterns, '\n') == 0) {
 608                 /* ignore empty line like grep does */
 609                 if (sb.len == 0)
 610                         continue;
 611                 append_grep_pattern(grep_opt, strbuf_detach(&sb, NULL), arg,
 612                                     ++lno, GREP_PATTERN);
 613         }
 614         fclose(patterns);
 615         strbuf_release(&sb);
 616         return 0;
 617 }
 618
 619 static int not_callback(const struct option *opt, const char *arg, int unset)
 620 {
 621         struct grep_opt *grep_opt = opt->value;
 622         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 623         return 0;
 624 }
 625
 626 static int and_callback(const struct option *opt, const char *arg, int unset)
 627 {
 628         struct grep_opt *grep_opt = opt->value;
 629         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 630         return 0;
 631 }
 632
 633 static int open_callback(const struct option *opt, const char *arg, int unset)
 634 {
 635         struct grep_opt *grep_opt = opt->value;
 636         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 637         return 0;
 638 }
 639
 640 static int close_callback(const struct option *opt, const char *arg, int unset)
 641 {
 642         struct grep_opt *grep_opt = opt->value;
 643         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 644         return 0;
 645 }
 646
 647 static int pattern_callback(const struct option *opt, const char *arg,
 648                             int unset)
 649 {
 650         struct grep_opt *grep_opt = opt->value;
 651         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 652         return 0;
 653 }
 654
 655 static int help_callback(const struct option *opt, const char *arg, int unset)
 656 {
 657         return -1;
 658 }
 659
 660 int cmd_grep(int argc, const char **argv, const char *prefix)
 661 {
 662         int hit = 0;
 663         int cached = 0;
 664         int external_grep_allowed = 1;
 665         int seen_dashdash = 0;
 666         struct grep_opt opt;
 667         struct object_array list = { 0, 0, NULL };
 668         const char **paths = NULL;
 669         int i;
 670         int dummy;
 671         struct option options[] = {
 672                 OPT_BOOLEAN(0, "cached", &cached,
 673                         "search in index instead of in the work tree"),
 674                 OPT_GROUP(""),
 675                 OPT_BOOLEAN('v', "invert-match", &opt.invert,
 676                         "show non-matching lines"),
 677                 OPT_BIT('i', "ignore-case", &opt.regflags,
 678                         "case insensitive matching", REG_ICASE),
 679                 OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
 680                         "match patterns only at word boundaries"),
 681                 OPT_SET_INT('a', "text", &opt.binary,
 682                         "process binary files as text", GREP_BINARY_TEXT),
 683                 OPT_SET_INT('I', NULL, &opt.binary,
 684                         "don't match patterns in binary files",
 685                         GREP_BINARY_NOMATCH),
 686                 OPT_GROUP(""),
 687                 OPT_BIT('E', "extended-regexp", &opt.regflags,
 688                         "use extended POSIX regular expressions", REG_EXTENDED),
 689                 OPT_NEGBIT('G', "basic-regexp", &opt.regflags,
 690                         "use basic POSIX regular expressions (default)",
 691                         REG_EXTENDED),
 692                 OPT_BOOLEAN('F', "fixed-strings", &opt.fixed,
 693                         "interpret patterns as fixed strings"),
 694                 OPT_GROUP(""),
 695                 OPT_BOOLEAN('n', NULL, &opt.linenum, "show line numbers"),
 696                 OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
 697                 OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
 698                 OPT_NEGBIT(0, "full-name", &opt.relative,
 699                         "show filenames relative to top directory", 1),
 700                 OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
 701                         "show only filenames instead of matching lines"),
 702                 OPT_BOOLEAN(0, "name-only", &opt.name_only,
 703                         "synonym for --files-with-matches"),
 704                 OPT_BOOLEAN('L', "files-without-match",
 705                         &opt.unmatch_name_only,
 706                         "show only the names of files without match"),
 707                 OPT_BOOLEAN('z', "null", &opt.null_following_name,
 708                         "print NUL after filenames"),
 709                 OPT_BOOLEAN('c', "count", &opt.count,
 710                         "show the number of matches instead of matching lines"),
 711                 OPT_SET_INT(0, "color", &opt.color, "highlight matches", 1),
 712                 OPT_GROUP(""),
 713                 OPT_CALLBACK('C', NULL, &opt, "n",
 714                         "show <n> context lines before and after matches",
 715                         context_callback),
 716                 OPT_INTEGER('B', NULL, &opt.pre_context,
 717                         "show <n> context lines before matches"),
 718                 OPT_INTEGER('A', NULL, &opt.post_context,
 719                         "show <n> context lines after matches"),
 720                 OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
 721                         context_callback),
 722                 OPT_BOOLEAN('p', "show-function", &opt.funcname,
 723                         "show a line with the function name before matches"),
 724                 OPT_GROUP(""),
 725                 OPT_CALLBACK('f', NULL, &opt, "file",
 726                         "read patterns from file", file_callback),
 727                 { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
 728                         "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
 729                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 730                   "combine patterns specified with -e",
 731                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 732                 OPT_BOOLEAN(0, "or", &dummy, ""),
 733                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 734                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 735                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 736                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 737                   open_callback },
 738                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 739                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 740                   close_callback },
 741                 OPT_BOOLEAN(0, "all-match", &opt.all_match,
 742                         "show only matches from files that match all patterns"),
 743                 OPT_GROUP(""),
 744 #if NO_EXTERNAL_GREP
 745                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed,
 746                         "allow calling of grep(1) (ignored by this build)"),
 747 #else
 748                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed,
 749                         "allow calling of grep(1) (default)"),
 750 #endif
 751                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
 752                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 753                 OPT_END()
 754         };
 755
 756         memset(&opt, 0, sizeof(opt));
 757         opt.prefix = prefix;
 758         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 759         opt.relative = 1;
 760         opt.pathname = 1;
 761         opt.pattern_tail = &opt.pattern_list;
 762         opt.regflags = REG_NEWLINE;
 763
 764         strcpy(opt.color_match, GIT_COLOR_RED GIT_COLOR_BOLD);
 765         opt.color = -1;
 766         git_config(grep_config, &opt);
 767         if (opt.color == -1)
 768                 opt.color = git_use_color_default;
 769
 770         /*
 771          * If there is no -- then the paths must exist in the working
 772          * tree.  If there is no explicit pattern specified with -e or
 773          * -f, we take the first unrecognized non option to be the
 774          * pattern, but then what follows it must be zero or more
 775          * valid refs up to the -- (if exists), and then existing
 776          * paths.  If there is an explicit pattern, then the first
 777          * unrecognized non option is the beginning of the refs list
 778          * that continues up to the -- (if exists), and then paths.
 779          */
 780         argc = parse_options(argc, argv, prefix, options, grep_usage,
 781                              PARSE_OPT_KEEP_DASHDASH |
 782                              PARSE_OPT_STOP_AT_NON_OPTION |
 783                              PARSE_OPT_NO_INTERNAL_HELP);
 784
 785         /* First unrecognized non-option token */
 786         if (argc > 0 && !opt.pattern_list) {
 787                 append_grep_pattern(&opt, argv[0], "command line", 0,
 788                                     GREP_PATTERN);
 789                 argv++;
 790                 argc--;
 791         }
 792
 793         if ((opt.color && !opt.color_external) || opt.funcname)
 794                 external_grep_allowed = 0;
 795         if (!opt.pattern_list)
 796                 die("no pattern given.");
 797         if ((opt.regflags != REG_NEWLINE) && opt.fixed)
 798                 die("cannot mix --fixed-strings and regexp");
 799         compile_grep_patterns(&opt);
 800
 801         /* Check revs and then paths */
 802         for (i = 0; i < argc; i++) {
 803                 const char *arg = argv[i];
 804                 unsigned char sha1[20];
 805                 /* Is it a rev? */
 806                 if (!get_sha1(arg, sha1)) {
 807                         struct object *object = parse_object(sha1);
 808                         if (!object)
 809                                 die("bad object %s", arg);
 810                         add_object_array(object, arg, &list);
 811                         continue;
 812                 }
 813                 if (!strcmp(arg, "--")) {
 814                         i++;
 815                         seen_dashdash = 1;
 816                 }
 817                 break;
 818         }
 819
 820         /* The rest are paths */
 821         if (!seen_dashdash) {
 822                 int j;
 823                 for (j = i; j < argc; j++)
 824                         verify_filename(prefix, argv[j]);
 825         }
 826
 827         if (i < argc)
 828                 paths = get_pathspec(prefix, argv + i);
 829         else if (prefix) {
 830                 paths = xcalloc(2, sizeof(const char *));
 831                 paths[0] = prefix;
 832                 paths[1] = NULL;
 833         }
 834
 835         if (!list.nr) {
 836                 if (!cached)
 837                         setup_work_tree();
 838                 return !grep_cache(&opt, paths, cached, external_grep_allowed);
 839         }
 840
 841         if (cached)
 842                 die("both --cached and trees are given.");
 843
 844         for (i = 0; i < list.nr; i++) {
 845                 struct object *real_obj;
 846                 real_obj = deref_tag(list.objects[i].item, NULL, 0);
 847                 if (grep_object(&opt, paths, real_obj, list.objects[i].name))
 848                         hit = 1;
 849         }
 850         free_grep_patterns(&opt);
 851         return !hit;
 852 }