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  * Return non-zero if max_depth is negative or path has no more then max_depth
  58  * slashes.
  59  */
  60 static int accept_subdir(const char *path, int max_depth)
  61 {
  62         if (max_depth < 0)
  63                 return 1;
  64
  65         while ((path = strchr(path, '/')) != NULL) {
  66                 max_depth--;
  67                 if (max_depth < 0)
  68                         return 0;
  69                 path++;
  70         }
  71         return 1;
  72 }
  73
  74 /*
  75  * Return non-zero if name is a subdirectory of match and is not too deep.
  76  */
  77 static int is_subdir(const char *name, int namelen,
  78                 const char *match, int matchlen, int max_depth)
  79 {
  80         if (matchlen > namelen || strncmp(name, match, matchlen))
  81                 return 0;
  82
  83         if (name[matchlen] == '\0') /* exact match */
  84                 return 1;
  85
  86         if (!matchlen || match[matchlen-1] == '/' || name[matchlen] == '/')
  87                 return accept_subdir(name + matchlen + 1, max_depth);
  88
  89         return 0;
  90 }
  91
  92 /*
  93  * git grep pathspecs are somewhat different from diff-tree pathspecs;
  94  * pathname wildcards are allowed.
  95  */
  96 static int pathspec_matches(const char **paths, const char *name, int max_depth)
  97 {
  98         int namelen, i;
  99         if (!paths || !*paths)
 100                 return accept_subdir(name, max_depth);
 101         namelen = strlen(name);
 102         for (i = 0; paths[i]; i++) {
 103                 const char *match = paths[i];
 104                 int matchlen = strlen(match);
 105                 const char *cp, *meta;
 106
 107                 if (is_subdir(name, namelen, match, matchlen, max_depth))
 108                         return 1;
 109                 if (!fnmatch(match, name, 0))
 110                         return 1;
 111                 if (name[namelen-1] != '/')
 112                         continue;
 113
 114                 /* We are being asked if the directory ("name") is worth
 115                  * descending into.
 116                  *
 117                  * Find the longest leading directory name that does
 118                  * not have metacharacter in the pathspec; the name
 119                  * we are looking at must overlap with that directory.
 120                  */
 121                 for (cp = match, meta = NULL; cp - match < matchlen; cp++) {
 122                         char ch = *cp;
 123                         if (ch == '*' || ch == '[' || ch == '?') {
 124                                 meta = cp;
 125                                 break;
 126                         }
 127                 }
 128                 if (!meta)
 129                         meta = cp; /* fully literal */
 130
 131                 if (namelen <= meta - match) {
 132                         /* Looking at "Documentation/" and
 133                          * the pattern says "Documentation/howto/", or
 134                          * "Documentation/diff*.txt".  The name we
 135                          * have should match prefix.
 136                          */
 137                         if (!memcmp(match, name, namelen))
 138                                 return 1;
 139                         continue;
 140                 }
 141
 142                 if (meta - match < namelen) {
 143                         /* Looking at "Documentation/howto/" and
 144                          * the pattern says "Documentation/h*";
 145                          * match up to "Do.../h"; this avoids descending
 146                          * into "Documentation/technical/".
 147                          */
 148                         if (!memcmp(match, name, meta - match))
 149                                 return 1;
 150                         continue;
 151                 }
 152         }
 153         return 0;
 154 }
 155
 156 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name, int tree_name_len)
 157 {
 158         unsigned long size;
 159         char *data;
 160         enum object_type type;
 161         int hit;
 162         struct strbuf pathbuf = STRBUF_INIT;
 163
 164         data = read_sha1_file(sha1, &type, &size);
 165         if (!data) {
 166                 error("'%s': unable to read %s", name, sha1_to_hex(sha1));
 167                 return 0;
 168         }
 169         if (opt->relative && opt->prefix_length) {
 170                 quote_path_relative(name + tree_name_len, -1, &pathbuf, opt->prefix);
 171                 strbuf_insert(&pathbuf, 0, name, tree_name_len);
 172                 name = pathbuf.buf;
 173         }
 174         hit = grep_buffer(opt, name, data, size);
 175         strbuf_release(&pathbuf);
 176         free(data);
 177         return hit;
 178 }
 179
 180 static int grep_file(struct grep_opt *opt, const char *filename)
 181 {
 182         struct stat st;
 183         int i;
 184         char *data;
 185         size_t sz;
 186         struct strbuf buf = STRBUF_INIT;
 187
 188         if (lstat(filename, &st) < 0) {
 189         err_ret:
 190                 if (errno != ENOENT)
 191                         error("'%s': %s", filename, strerror(errno));
 192                 return 0;
 193         }
 194         if (!st.st_size)
 195                 return 0; /* empty file -- no grep hit */
 196         if (!S_ISREG(st.st_mode))
 197                 return 0;
 198         sz = xsize_t(st.st_size);
 199         i = open(filename, O_RDONLY);
 200         if (i < 0)
 201                 goto err_ret;
 202         data = xmalloc(sz + 1);
 203         if (st.st_size != read_in_full(i, data, sz)) {
 204                 error("'%s': short read %s", filename, strerror(errno));
 205                 close(i);
 206                 free(data);
 207                 return 0;
 208         }
 209         close(i);
 210         if (opt->relative && opt->prefix_length)
 211                 filename = quote_path_relative(filename, -1, &buf, opt->prefix);
 212         i = grep_buffer(opt, filename, data, sz);
 213         strbuf_release(&buf);
 214         free(data);
 215         return i;
 216 }
 217
 218 #if !NO_EXTERNAL_GREP
 219 static int exec_grep(int argc, const char **argv)
 220 {
 221         pid_t pid;
 222         int status;
 223
 224         argv[argc] = NULL;
 225         pid = fork();
 226         if (pid < 0)
 227                 return pid;
 228         if (!pid) {
 229                 execvp("grep", (char **) argv);
 230                 exit(255);
 231         }
 232         while (waitpid(pid, &status, 0) < 0) {
 233                 if (errno == EINTR)
 234                         continue;
 235                 return -1;
 236         }
 237         if (WIFEXITED(status)) {
 238                 if (!WEXITSTATUS(status))
 239                         return 1;
 240                 return 0;
 241         }
 242         return -1;
 243 }
 244
 245 #define MAXARGS 1000
 246 #define ARGBUF 4096
 247 #define push_arg(a) do { \
 248         if (nr < MAXARGS) argv[nr++] = (a); \
 249         else die("maximum number of args exceeded"); \
 250         } while (0)
 251
 252 /*
 253  * If you send a singleton filename to grep, it does not give
 254  * the name of the file.  GNU grep has "-H" but we would want
 255  * that behaviour in a portable way.
 256  *
 257  * So we keep two pathnames in argv buffer unsent to grep in
 258  * the main loop if we need to do more than one grep.
 259  */
 260 static int flush_grep(struct grep_opt *opt,
 261                       int argc, int arg0, const char **argv, int *kept)
 262 {
 263         int status;
 264         int count = argc - arg0;
 265         const char *kept_0 = NULL;
 266
 267         if (count <= 2) {
 268                 /*
 269                  * Because we keep at least 2 paths in the call from
 270                  * the main loop (i.e. kept != NULL), and MAXARGS is
 271                  * far greater than 2, this usually is a call to
 272                  * conclude the grep.  However, the user could attempt
 273                  * to overflow the argv buffer by giving too many
 274                  * options to leave very small number of real
 275                  * arguments even for the call in the main loop.
 276                  */
 277                 if (kept)
 278                         die("insanely many options to grep");
 279
 280                 /*
 281                  * If we have two or more paths, we do not have to do
 282                  * anything special, but we need to push /dev/null to
 283                  * get "-H" behaviour of GNU grep portably but when we
 284                  * are not doing "-l" nor "-L" nor "-c".
 285                  */
 286                 if (count == 1 &&
 287                     !opt->name_only &&
 288                     !opt->unmatch_name_only &&
 289                     !opt->count) {
 290                         argv[argc++] = "/dev/null";
 291                         argv[argc] = NULL;
 292                 }
 293         }
 294
 295         else if (kept) {
 296                 /*
 297                  * Called because we found many paths and haven't finished
 298                  * iterating over the cache yet.  We keep two paths
 299                  * for the concluding call.  argv[argc-2] and argv[argc-1]
 300                  * has the last two paths, so save the first one away,
 301                  * replace it with NULL while sending the list to grep,
 302                  * and recover them after we are done.
 303                  */
 304                 *kept = 2;
 305                 kept_0 = argv[argc-2];
 306                 argv[argc-2] = NULL;
 307                 argc -= 2;
 308         }
 309
 310         if (opt->pre_context || opt->post_context) {
 311                 /*
 312                  * grep handles hunk marks between files, but we need to
 313                  * do that ourselves between multiple calls.
 314                  */
 315                 if (opt->show_hunk_mark)
 316                         write_or_die(1, "--\n", 3);
 317                 else
 318                         opt->show_hunk_mark = 1;
 319         }
 320
 321         status = exec_grep(argc, argv);
 322
 323         if (kept_0) {
 324                 /*
 325                  * Then recover them.  Now the last arg is beyond the
 326                  * terminating NULL which is at argc, and the second
 327                  * from the last is what we saved away in kept_0
 328                  */
 329                 argv[arg0++] = kept_0;
 330                 argv[arg0] = argv[argc+1];
 331         }
 332         return status;
 333 }
 334
 335 static void grep_add_color(struct strbuf *sb, const char *escape_seq)
 336 {
 337         size_t orig_len = sb->len;
 338
 339         while (*escape_seq) {
 340                 if (*escape_seq == 'm')
 341                         strbuf_addch(sb, ';');
 342                 else if (*escape_seq != '\033' && *escape_seq  != '[')
 343                         strbuf_addch(sb, *escape_seq);
 344                 escape_seq++;
 345         }
 346         if (sb->len > orig_len && sb->buf[sb->len - 1] == ';')
 347                 strbuf_setlen(sb, sb->len - 1);
 348 }
 349
 350 static int external_grep(struct grep_opt *opt, const char **paths, int cached)
 351 {
 352         int i, nr, argc, hit, len, status;
 353         const char *argv[MAXARGS+1];
 354         char randarg[ARGBUF];
 355         char *argptr = randarg;
 356         struct grep_pat *p;
 357
 358         if (opt->extended || (opt->relative && opt->prefix_length))
 359                 return -1;
 360         len = nr = 0;
 361         push_arg("grep");
 362         if (opt->fixed)
 363                 push_arg("-F");
 364         if (opt->linenum)
 365                 push_arg("-n");
 366         if (!opt->pathname)
 367                 push_arg("-h");
 368         if (opt->regflags & REG_EXTENDED)
 369                 push_arg("-E");
 370         if (opt->regflags & REG_ICASE)
 371                 push_arg("-i");
 372         if (opt->binary == GREP_BINARY_NOMATCH)
 373                 push_arg("-I");
 374         if (opt->word_regexp)
 375                 push_arg("-w");
 376         if (opt->name_only)
 377                 push_arg("-l");
 378         if (opt->unmatch_name_only)
 379                 push_arg("-L");
 380         if (opt->null_following_name)
 381                 /* in GNU grep git's "-z" translates to "-Z" */
 382                 push_arg("-Z");
 383         if (opt->count)
 384                 push_arg("-c");
 385         if (opt->post_context || opt->pre_context) {
 386                 if (opt->post_context != opt->pre_context) {
 387                         if (opt->pre_context) {
 388                                 push_arg("-B");
 389                                 len += snprintf(argptr, sizeof(randarg)-len,
 390                                                 "%u", opt->pre_context) + 1;
 391                                 if (sizeof(randarg) <= len)
 392                                         die("maximum length of args exceeded");
 393                                 push_arg(argptr);
 394                                 argptr += len;
 395                         }
 396                         if (opt->post_context) {
 397                                 push_arg("-A");
 398                                 len += snprintf(argptr, sizeof(randarg)-len,
 399                                                 "%u", opt->post_context) + 1;
 400                                 if (sizeof(randarg) <= len)
 401                                         die("maximum length of args exceeded");
 402                                 push_arg(argptr);
 403                                 argptr += len;
 404                         }
 405                 }
 406                 else {
 407                         push_arg("-C");
 408                         len += snprintf(argptr, sizeof(randarg)-len,
 409                                         "%u", opt->post_context) + 1;
 410                         if (sizeof(randarg) <= len)
 411                                 die("maximum length of args exceeded");
 412                         push_arg(argptr);
 413                         argptr += len;
 414                 }
 415         }
 416         for (p = opt->pattern_list; p; p = p->next) {
 417                 push_arg("-e");
 418                 push_arg(p->pattern);
 419         }
 420         if (opt->color) {
 421                 struct strbuf sb = STRBUF_INIT;
 422
 423                 grep_add_color(&sb, opt->color_match);
 424                 setenv("GREP_COLOR", sb.buf, 1);
 425
 426                 strbuf_reset(&sb);
 427                 strbuf_addstr(&sb, "mt=");
 428                 grep_add_color(&sb, opt->color_match);
 429                 strbuf_addstr(&sb, ":sl=:cx=:fn=:ln=:bn=:se=");
 430                 setenv("GREP_COLORS", sb.buf, 1);
 431
 432                 strbuf_release(&sb);
 433
 434                 if (opt->color_external && strlen(opt->color_external) > 0)
 435                         push_arg(opt->color_external);
 436         }
 437
 438         hit = 0;
 439         argc = nr;
 440         for (i = 0; i < active_nr; i++) {
 441                 struct cache_entry *ce = active_cache[i];
 442                 char *name;
 443                 int kept;
 444                 if (!S_ISREG(ce->ce_mode))
 445                         continue;
 446                 if (!pathspec_matches(paths, ce->name, opt->max_depth))
 447                         continue;
 448                 name = ce->name;
 449                 if (name[0] == '-') {
 450                         int len = ce_namelen(ce);
 451                         name = xmalloc(len + 3);
 452                         memcpy(name, "./", 2);
 453                         memcpy(name + 2, ce->name, len + 1);
 454                 }
 455                 argv[argc++] = name;
 456                 if (MAXARGS <= argc) {
 457                         status = flush_grep(opt, argc, nr, argv, &kept);
 458                         if (0 < status)
 459                                 hit = 1;
 460                         argc = nr + kept;
 461                 }
 462                 if (ce_stage(ce)) {
 463                         do {
 464                                 i++;
 465                         } while (i < active_nr &&
 466                                  !strcmp(ce->name, active_cache[i]->name));
 467                         i--; /* compensate for loop control */
 468                 }
 469         }
 470         if (argc > nr) {
 471                 status = flush_grep(opt, argc, nr, argv, NULL);
 472                 if (0 < status)
 473                         hit = 1;
 474         }
 475         return hit;
 476 }
 477 #endif
 478
 479 static int grep_cache(struct grep_opt *opt, const char **paths, int cached,
 480                       int external_grep_allowed)
 481 {
 482         int hit = 0;
 483         int nr;
 484         read_cache();
 485
 486 #if !NO_EXTERNAL_GREP
 487         /*
 488          * Use the external "grep" command for the case where
 489          * we grep through the checked-out files. It tends to
 490          * be a lot more optimized
 491          */
 492         if (!cached && external_grep_allowed) {
 493                 hit = external_grep(opt, paths, cached);
 494                 if (hit >= 0)
 495                         return hit;
 496                 hit = 0;
 497         }
 498 #endif
 499
 500         for (nr = 0; nr < active_nr; nr++) {
 501                 struct cache_entry *ce = active_cache[nr];
 502                 if (!S_ISREG(ce->ce_mode))
 503                         continue;
 504                 if (!pathspec_matches(paths, ce->name, opt->max_depth))
 505                         continue;
 506                 /*
 507                  * If CE_VALID is on, we assume worktree file and its cache entry
 508                  * are identical, even if worktree file has been modified, so use
 509                  * cache version instead
 510                  */
 511                 if (cached || (ce->ce_flags & CE_VALID)) {
 512                         if (ce_stage(ce))
 513                                 continue;
 514                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 515                 }
 516                 else
 517                         hit |= grep_file(opt, ce->name);
 518                 if (ce_stage(ce)) {
 519                         do {
 520                                 nr++;
 521                         } while (nr < active_nr &&
 522                                  !strcmp(ce->name, active_cache[nr]->name));
 523                         nr--; /* compensate for loop control */
 524                 }
 525         }
 526         free_grep_patterns(opt);
 527         return hit;
 528 }
 529
 530 static int grep_tree(struct grep_opt *opt, const char **paths,
 531                      struct tree_desc *tree,
 532                      const char *tree_name, const char *base)
 533 {
 534         int len;
 535         int hit = 0;
 536         struct name_entry entry;
 537         char *down;
 538         int tn_len = strlen(tree_name);
 539         struct strbuf pathbuf;
 540
 541         strbuf_init(&pathbuf, PATH_MAX + tn_len);
 542
 543         if (tn_len) {
 544                 strbuf_add(&pathbuf, tree_name, tn_len);
 545                 strbuf_addch(&pathbuf, ':');
 546                 tn_len = pathbuf.len;
 547         }
 548         strbuf_addstr(&pathbuf, base);
 549         len = pathbuf.len;
 550
 551         while (tree_entry(tree, &entry)) {
 552                 int te_len = tree_entry_len(entry.path, entry.sha1);
 553                 pathbuf.len = len;
 554                 strbuf_add(&pathbuf, entry.path, te_len);
 555
 556                 if (S_ISDIR(entry.mode))
 557                         /* Match "abc/" against pathspec to
 558                          * decide if we want to descend into "abc"
 559                          * directory.
 560                          */
 561                         strbuf_addch(&pathbuf, '/');
 562
 563                 down = pathbuf.buf + tn_len;
 564                 if (!pathspec_matches(paths, down, opt->max_depth))
 565                         ;
 566                 else if (S_ISREG(entry.mode))
 567                         hit |= grep_sha1(opt, entry.sha1, pathbuf.buf, tn_len);
 568                 else if (S_ISDIR(entry.mode)) {
 569                         enum object_type type;
 570                         struct tree_desc sub;
 571                         void *data;
 572                         unsigned long size;
 573
 574                         data = read_sha1_file(entry.sha1, &type, &size);
 575                         if (!data)
 576                                 die("unable to read tree (%s)",
 577                                     sha1_to_hex(entry.sha1));
 578                         init_tree_desc(&sub, data, size);
 579                         hit |= grep_tree(opt, paths, &sub, tree_name, down);
 580                         free(data);
 581                 }
 582         }
 583         strbuf_release(&pathbuf);
 584         return hit;
 585 }
 586
 587 static int grep_object(struct grep_opt *opt, const char **paths,
 588                        struct object *obj, const char *name)
 589 {
 590         if (obj->type == OBJ_BLOB)
 591                 return grep_sha1(opt, obj->sha1, name, 0);
 592         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 593                 struct tree_desc tree;
 594                 void *data;
 595                 unsigned long size;
 596                 int hit;
 597                 data = read_object_with_reference(obj->sha1, tree_type,
 598                                                   &size, NULL);
 599                 if (!data)
 600                         die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
 601                 init_tree_desc(&tree, data, size);
 602                 hit = grep_tree(opt, paths, &tree, name, "");
 603                 free(data);
 604                 return hit;
 605         }
 606         die("unable to grep from object of type %s", typename(obj->type));
 607 }
 608
 609 static int context_callback(const struct option *opt, const char *arg,
 610                             int unset)
 611 {
 612         struct grep_opt *grep_opt = opt->value;
 613         int value;
 614         const char *endp;
 615
 616         if (unset) {
 617                 grep_opt->pre_context = grep_opt->post_context = 0;
 618                 return 0;
 619         }
 620         value = strtol(arg, (char **)&endp, 10);
 621         if (*endp) {
 622                 return error("switch `%c' expects a numerical value",
 623                              opt->short_name);
 624         }
 625         grep_opt->pre_context = grep_opt->post_context = value;
 626         return 0;
 627 }
 628
 629 static int file_callback(const struct option *opt, const char *arg, int unset)
 630 {
 631         struct grep_opt *grep_opt = opt->value;
 632         FILE *patterns;
 633         int lno = 0;
 634         struct strbuf sb;
 635
 636         patterns = fopen(arg, "r");
 637         if (!patterns)
 638                 die_errno("cannot open '%s'", arg);
 639         while (strbuf_getline(&sb, patterns, '\n') == 0) {
 640                 /* ignore empty line like grep does */
 641                 if (sb.len == 0)
 642                         continue;
 643                 append_grep_pattern(grep_opt, strbuf_detach(&sb, NULL), arg,
 644                                     ++lno, GREP_PATTERN);
 645         }
 646         fclose(patterns);
 647         strbuf_release(&sb);
 648         return 0;
 649 }
 650
 651 static int not_callback(const struct option *opt, const char *arg, int unset)
 652 {
 653         struct grep_opt *grep_opt = opt->value;
 654         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 655         return 0;
 656 }
 657
 658 static int and_callback(const struct option *opt, const char *arg, int unset)
 659 {
 660         struct grep_opt *grep_opt = opt->value;
 661         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 662         return 0;
 663 }
 664
 665 static int open_callback(const struct option *opt, const char *arg, int unset)
 666 {
 667         struct grep_opt *grep_opt = opt->value;
 668         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 669         return 0;
 670 }
 671
 672 static int close_callback(const struct option *opt, const char *arg, int unset)
 673 {
 674         struct grep_opt *grep_opt = opt->value;
 675         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 676         return 0;
 677 }
 678
 679 static int pattern_callback(const struct option *opt, const char *arg,
 680                             int unset)
 681 {
 682         struct grep_opt *grep_opt = opt->value;
 683         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 684         return 0;
 685 }
 686
 687 static int help_callback(const struct option *opt, const char *arg, int unset)
 688 {
 689         return -1;
 690 }
 691
 692 int cmd_grep(int argc, const char **argv, const char *prefix)
 693 {
 694         int hit = 0;
 695         int cached = 0;
 696         int external_grep_allowed = 1;
 697         int seen_dashdash = 0;
 698         struct grep_opt opt;
 699         struct object_array list = { 0, 0, NULL };
 700         const char **paths = NULL;
 701         int i;
 702         int dummy;
 703         struct option options[] = {
 704                 OPT_BOOLEAN(0, "cached", &cached,
 705                         "search in index instead of in the work tree"),
 706                 OPT_GROUP(""),
 707                 OPT_BOOLEAN('v', "invert-match", &opt.invert,
 708                         "show non-matching lines"),
 709                 OPT_BIT('i', "ignore-case", &opt.regflags,
 710                         "case insensitive matching", REG_ICASE),
 711                 OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
 712                         "match patterns only at word boundaries"),
 713                 OPT_SET_INT('a', "text", &opt.binary,
 714                         "process binary files as text", GREP_BINARY_TEXT),
 715                 OPT_SET_INT('I', NULL, &opt.binary,
 716                         "don't match patterns in binary files",
 717                         GREP_BINARY_NOMATCH),
 718                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, "depth",
 719                         "descend at most <depth> levels", PARSE_OPT_NONEG,
 720                         NULL, 1 },
 721                 OPT_GROUP(""),
 722                 OPT_BIT('E', "extended-regexp", &opt.regflags,
 723                         "use extended POSIX regular expressions", REG_EXTENDED),
 724                 OPT_NEGBIT('G', "basic-regexp", &opt.regflags,
 725                         "use basic POSIX regular expressions (default)",
 726                         REG_EXTENDED),
 727                 OPT_BOOLEAN('F', "fixed-strings", &opt.fixed,
 728                         "interpret patterns as fixed strings"),
 729                 OPT_GROUP(""),
 730                 OPT_BOOLEAN('n', NULL, &opt.linenum, "show line numbers"),
 731                 OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
 732                 OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
 733                 OPT_NEGBIT(0, "full-name", &opt.relative,
 734                         "show filenames relative to top directory", 1),
 735                 OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
 736                         "show only filenames instead of matching lines"),
 737                 OPT_BOOLEAN(0, "name-only", &opt.name_only,
 738                         "synonym for --files-with-matches"),
 739                 OPT_BOOLEAN('L', "files-without-match",
 740                         &opt.unmatch_name_only,
 741                         "show only the names of files without match"),
 742                 OPT_BOOLEAN('z', "null", &opt.null_following_name,
 743                         "print NUL after filenames"),
 744                 OPT_BOOLEAN('c', "count", &opt.count,
 745                         "show the number of matches instead of matching lines"),
 746                 OPT_SET_INT(0, "color", &opt.color, "highlight matches", 1),
 747                 OPT_GROUP(""),
 748                 OPT_CALLBACK('C', NULL, &opt, "n",
 749                         "show <n> context lines before and after matches",
 750                         context_callback),
 751                 OPT_INTEGER('B', NULL, &opt.pre_context,
 752                         "show <n> context lines before matches"),
 753                 OPT_INTEGER('A', NULL, &opt.post_context,
 754                         "show <n> context lines after matches"),
 755                 OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
 756                         context_callback),
 757                 OPT_BOOLEAN('p', "show-function", &opt.funcname,
 758                         "show a line with the function name before matches"),
 759                 OPT_GROUP(""),
 760                 OPT_CALLBACK('f', NULL, &opt, "file",
 761                         "read patterns from file", file_callback),
 762                 { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
 763                         "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
 764                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 765                   "combine patterns specified with -e",
 766                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 767                 OPT_BOOLEAN(0, "or", &dummy, ""),
 768                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 769                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 770                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 771                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 772                   open_callback },
 773                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 774                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 775                   close_callback },
 776                 OPT_BOOLEAN(0, "all-match", &opt.all_match,
 777                         "show only matches from files that match all patterns"),
 778                 OPT_GROUP(""),
 779 #if NO_EXTERNAL_GREP
 780                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed,
 781                         "allow calling of grep(1) (ignored by this build)"),
 782 #else
 783                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed,
 784                         "allow calling of grep(1) (default)"),
 785 #endif
 786                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
 787                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 788                 OPT_END()
 789         };
 790
 791         memset(&opt, 0, sizeof(opt));
 792         opt.prefix = prefix;
 793         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 794         opt.relative = 1;
 795         opt.pathname = 1;
 796         opt.pattern_tail = &opt.pattern_list;
 797         opt.regflags = REG_NEWLINE;
 798         opt.max_depth = -1;
 799
 800         strcpy(opt.color_match, GIT_COLOR_RED GIT_COLOR_BOLD);
 801         opt.color = -1;
 802         git_config(grep_config, &opt);
 803         if (opt.color == -1)
 804                 opt.color = git_use_color_default;
 805
 806         /*
 807          * If there is no -- then the paths must exist in the working
 808          * tree.  If there is no explicit pattern specified with -e or
 809          * -f, we take the first unrecognized non option to be the
 810          * pattern, but then what follows it must be zero or more
 811          * valid refs up to the -- (if exists), and then existing
 812          * paths.  If there is an explicit pattern, then the first
 813          * unrecognized non option is the beginning of the refs list
 814          * that continues up to the -- (if exists), and then paths.
 815          */
 816         argc = parse_options(argc, argv, prefix, options, grep_usage,
 817                              PARSE_OPT_KEEP_DASHDASH |
 818                              PARSE_OPT_STOP_AT_NON_OPTION |
 819                              PARSE_OPT_NO_INTERNAL_HELP);
 820
 821         /* First unrecognized non-option token */
 822         if (argc > 0 && !opt.pattern_list) {
 823                 append_grep_pattern(&opt, argv[0], "command line", 0,
 824                                     GREP_PATTERN);
 825                 argv++;
 826                 argc--;
 827         }
 828
 829         if ((opt.color && !opt.color_external) || opt.funcname)
 830                 external_grep_allowed = 0;
 831         if (!opt.pattern_list)
 832                 die("no pattern given.");
 833         if ((opt.regflags != REG_NEWLINE) && opt.fixed)
 834                 die("cannot mix --fixed-strings and regexp");
 835         compile_grep_patterns(&opt);
 836
 837         /* Check revs and then paths */
 838         for (i = 0; i < argc; i++) {
 839                 const char *arg = argv[i];
 840                 unsigned char sha1[20];
 841                 /* Is it a rev? */
 842                 if (!get_sha1(arg, sha1)) {
 843                         struct object *object = parse_object(sha1);
 844                         if (!object)
 845                                 die("bad object %s", arg);
 846                         add_object_array(object, arg, &list);
 847                         continue;
 848                 }
 849                 if (!strcmp(arg, "--")) {
 850                         i++;
 851                         seen_dashdash = 1;
 852                 }
 853                 break;
 854         }
 855
 856         /* The rest are paths */
 857         if (!seen_dashdash) {
 858                 int j;
 859                 for (j = i; j < argc; j++)
 860                         verify_filename(prefix, argv[j]);
 861         }
 862
 863         if (i < argc)
 864                 paths = get_pathspec(prefix, argv + i);
 865         else if (prefix) {
 866                 paths = xcalloc(2, sizeof(const char *));
 867                 paths[0] = prefix;
 868                 paths[1] = NULL;
 869         }
 870
 871         if (!list.nr) {
 872                 if (!cached)
 873                         setup_work_tree();
 874                 return !grep_cache(&opt, paths, cached, external_grep_allowed);
 875         }
 876
 877         if (cached)
 878                 die("both --cached and trees are given.");
 879
 880         for (i = 0; i < list.nr; i++) {
 881                 struct object *real_obj;
 882                 real_obj = deref_tag(list.objects[i].item, NULL, 0);
 883                 if (grep_object(&opt, paths, real_obj, list.objects[i].name))
 884                         hit = 1;
 885         }
 886         free_grep_patterns(&opt);
 887         return !hit;
 888 }