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 (!S_ISREG(st.st_mode))
 195                 return 0;
 196         sz = xsize_t(st.st_size);
 197         i = open(filename, O_RDONLY);
 198         if (i < 0)
 199                 goto err_ret;
 200         data = xmalloc(sz + 1);
 201         if (st.st_size != read_in_full(i, data, sz)) {
 202                 error("'%s': short read %s", filename, strerror(errno));
 203                 close(i);
 204                 free(data);
 205                 return 0;
 206         }
 207         close(i);
 208         data[sz] = 0;
 209         if (opt->relative && opt->prefix_length)
 210                 filename = quote_path_relative(filename, -1, &buf, opt->prefix);
 211         i = grep_buffer(opt, filename, data, sz);
 212         strbuf_release(&buf);
 213         free(data);
 214         return i;
 215 }
 216
 217 #if !NO_EXTERNAL_GREP
 218 static int exec_grep(int argc, const char **argv)
 219 {
 220         pid_t pid;
 221         int status;
 222
 223         argv[argc] = NULL;
 224         trace_argv_printf(argv, "trace: grep:");
 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 has_skip_worktree_entry(struct grep_opt *opt, const char **paths)
 351 {
 352         int nr;
 353         for (nr = 0; nr < active_nr; nr++) {
 354                 struct cache_entry *ce = active_cache[nr];
 355                 if (!S_ISREG(ce->ce_mode))
 356                         continue;
 357                 if (!pathspec_matches(paths, ce->name, opt->max_depth))
 358                         continue;
 359                 if (ce_skip_worktree(ce))
 360                         return 1;
 361         }
 362         return 0;
 363 }
 364
 365 static int external_grep(struct grep_opt *opt, const char **paths, int cached)
 366 {
 367         int i, nr, argc, hit, len, status;
 368         const char *argv[MAXARGS+1];
 369         char randarg[ARGBUF];
 370         char *argptr = randarg;
 371         struct grep_pat *p;
 372
 373         if (opt->extended || (opt->relative && opt->prefix_length)
 374             || has_skip_worktree_entry(opt, paths))
 375                 return -1;
 376         len = nr = 0;
 377         push_arg("grep");
 378         if (opt->fixed)
 379                 push_arg("-F");
 380         if (opt->linenum)
 381                 push_arg("-n");
 382         if (!opt->pathname)
 383                 push_arg("-h");
 384         if (opt->regflags & REG_EXTENDED)
 385                 push_arg("-E");
 386         if (opt->ignore_case)
 387                 push_arg("-i");
 388         if (opt->binary == GREP_BINARY_NOMATCH)
 389                 push_arg("-I");
 390         if (opt->word_regexp)
 391                 push_arg("-w");
 392         if (opt->name_only)
 393                 push_arg("-l");
 394         if (opt->unmatch_name_only)
 395                 push_arg("-L");
 396         if (opt->null_following_name)
 397                 /* in GNU grep git's "-z" translates to "-Z" */
 398                 push_arg("-Z");
 399         if (opt->count)
 400                 push_arg("-c");
 401         if (opt->post_context || opt->pre_context) {
 402                 if (opt->post_context != opt->pre_context) {
 403                         if (opt->pre_context) {
 404                                 push_arg("-B");
 405                                 len += snprintf(argptr, sizeof(randarg)-len,
 406                                                 "%u", opt->pre_context) + 1;
 407                                 if (sizeof(randarg) <= len)
 408                                         die("maximum length of args exceeded");
 409                                 push_arg(argptr);
 410                                 argptr += len;
 411                         }
 412                         if (opt->post_context) {
 413                                 push_arg("-A");
 414                                 len += snprintf(argptr, sizeof(randarg)-len,
 415                                                 "%u", opt->post_context) + 1;
 416                                 if (sizeof(randarg) <= len)
 417                                         die("maximum length of args exceeded");
 418                                 push_arg(argptr);
 419                                 argptr += len;
 420                         }
 421                 }
 422                 else {
 423                         push_arg("-C");
 424                         len += snprintf(argptr, sizeof(randarg)-len,
 425                                         "%u", opt->post_context) + 1;
 426                         if (sizeof(randarg) <= len)
 427                                 die("maximum length of args exceeded");
 428                         push_arg(argptr);
 429                         argptr += len;
 430                 }
 431         }
 432         for (p = opt->pattern_list; p; p = p->next) {
 433                 push_arg("-e");
 434                 push_arg(p->pattern);
 435         }
 436         if (opt->color) {
 437                 struct strbuf sb = STRBUF_INIT;
 438
 439                 grep_add_color(&sb, opt->color_match);
 440                 setenv("GREP_COLOR", sb.buf, 1);
 441
 442                 strbuf_reset(&sb);
 443                 strbuf_addstr(&sb, "mt=");
 444                 grep_add_color(&sb, opt->color_match);
 445                 strbuf_addstr(&sb, ":sl=:cx=:fn=:ln=:bn=:se=");
 446                 setenv("GREP_COLORS", sb.buf, 1);
 447
 448                 strbuf_release(&sb);
 449
 450                 if (opt->color_external && strlen(opt->color_external) > 0)
 451                         push_arg(opt->color_external);
 452         } else {
 453                 unsetenv("GREP_COLOR");
 454                 unsetenv("GREP_COLORS");
 455         }
 456         unsetenv("GREP_OPTIONS");
 457
 458         hit = 0;
 459         argc = nr;
 460         for (i = 0; i < active_nr; i++) {
 461                 struct cache_entry *ce = active_cache[i];
 462                 char *name;
 463                 int kept;
 464                 if (!S_ISREG(ce->ce_mode))
 465                         continue;
 466                 if (!pathspec_matches(paths, ce->name, opt->max_depth))
 467                         continue;
 468                 name = ce->name;
 469                 if (name[0] == '-') {
 470                         int len = ce_namelen(ce);
 471                         name = xmalloc(len + 3);
 472                         memcpy(name, "./", 2);
 473                         memcpy(name + 2, ce->name, len + 1);
 474                 }
 475                 argv[argc++] = name;
 476                 if (MAXARGS <= argc) {
 477                         status = flush_grep(opt, argc, nr, argv, &kept);
 478                         if (0 < status)
 479                                 hit = 1;
 480                         argc = nr + kept;
 481                 }
 482                 if (ce_stage(ce)) {
 483                         do {
 484                                 i++;
 485                         } while (i < active_nr &&
 486                                  !strcmp(ce->name, active_cache[i]->name));
 487                         i--; /* compensate for loop control */
 488                 }
 489         }
 490         if (argc > nr) {
 491                 status = flush_grep(opt, argc, nr, argv, NULL);
 492                 if (0 < status)
 493                         hit = 1;
 494         }
 495         return hit;
 496 }
 497 #endif
 498
 499 static int grep_cache(struct grep_opt *opt, const char **paths, int cached,
 500                       int external_grep_allowed)
 501 {
 502         int hit = 0;
 503         int nr;
 504         read_cache();
 505
 506 #if !NO_EXTERNAL_GREP
 507         /*
 508          * Use the external "grep" command for the case where
 509          * we grep through the checked-out files. It tends to
 510          * be a lot more optimized
 511          */
 512         if (!cached && external_grep_allowed) {
 513                 hit = external_grep(opt, paths, cached);
 514                 if (hit >= 0)
 515                         return hit;
 516                 hit = 0;
 517         }
 518 #endif
 519
 520         for (nr = 0; nr < active_nr; nr++) {
 521                 struct cache_entry *ce = active_cache[nr];
 522                 if (!S_ISREG(ce->ce_mode))
 523                         continue;
 524                 if (!pathspec_matches(paths, ce->name, opt->max_depth))
 525                         continue;
 526                 /*
 527                  * If CE_VALID is on, we assume worktree file and its cache entry
 528                  * are identical, even if worktree file has been modified, so use
 529                  * cache version instead
 530                  */
 531                 if (cached || (ce->ce_flags & CE_VALID) || ce_skip_worktree(ce)) {
 532                         if (ce_stage(ce))
 533                                 continue;
 534                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 535                 }
 536                 else
 537                         hit |= grep_file(opt, ce->name);
 538                 if (ce_stage(ce)) {
 539                         do {
 540                                 nr++;
 541                         } while (nr < active_nr &&
 542                                  !strcmp(ce->name, active_cache[nr]->name));
 543                         nr--; /* compensate for loop control */
 544                 }
 545         }
 546         free_grep_patterns(opt);
 547         return hit;
 548 }
 549
 550 static int grep_tree(struct grep_opt *opt, const char **paths,
 551                      struct tree_desc *tree,
 552                      const char *tree_name, const char *base)
 553 {
 554         int len;
 555         int hit = 0;
 556         struct name_entry entry;
 557         char *down;
 558         int tn_len = strlen(tree_name);
 559         struct strbuf pathbuf;
 560
 561         strbuf_init(&pathbuf, PATH_MAX + tn_len);
 562
 563         if (tn_len) {
 564                 strbuf_add(&pathbuf, tree_name, tn_len);
 565                 strbuf_addch(&pathbuf, ':');
 566                 tn_len = pathbuf.len;
 567         }
 568         strbuf_addstr(&pathbuf, base);
 569         len = pathbuf.len;
 570
 571         while (tree_entry(tree, &entry)) {
 572                 int te_len = tree_entry_len(entry.path, entry.sha1);
 573                 pathbuf.len = len;
 574                 strbuf_add(&pathbuf, entry.path, te_len);
 575
 576                 if (S_ISDIR(entry.mode))
 577                         /* Match "abc/" against pathspec to
 578                          * decide if we want to descend into "abc"
 579                          * directory.
 580                          */
 581                         strbuf_addch(&pathbuf, '/');
 582
 583                 down = pathbuf.buf + tn_len;
 584                 if (!pathspec_matches(paths, down, opt->max_depth))
 585                         ;
 586                 else if (S_ISREG(entry.mode))
 587                         hit |= grep_sha1(opt, entry.sha1, pathbuf.buf, tn_len);
 588                 else if (S_ISDIR(entry.mode)) {
 589                         enum object_type type;
 590                         struct tree_desc sub;
 591                         void *data;
 592                         unsigned long size;
 593
 594                         data = read_sha1_file(entry.sha1, &type, &size);
 595                         if (!data)
 596                                 die("unable to read tree (%s)",
 597                                     sha1_to_hex(entry.sha1));
 598                         init_tree_desc(&sub, data, size);
 599                         hit |= grep_tree(opt, paths, &sub, tree_name, down);
 600                         free(data);
 601                 }
 602         }
 603         strbuf_release(&pathbuf);
 604         return hit;
 605 }
 606
 607 static int grep_object(struct grep_opt *opt, const char **paths,
 608                        struct object *obj, const char *name)
 609 {
 610         if (obj->type == OBJ_BLOB)
 611                 return grep_sha1(opt, obj->sha1, name, 0);
 612         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 613                 struct tree_desc tree;
 614                 void *data;
 615                 unsigned long size;
 616                 int hit;
 617                 data = read_object_with_reference(obj->sha1, tree_type,
 618                                                   &size, NULL);
 619                 if (!data)
 620                         die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
 621                 init_tree_desc(&tree, data, size);
 622                 hit = grep_tree(opt, paths, &tree, name, "");
 623                 free(data);
 624                 return hit;
 625         }
 626         die("unable to grep from object of type %s", typename(obj->type));
 627 }
 628
 629 static int context_callback(const struct option *opt, const char *arg,
 630                             int unset)
 631 {
 632         struct grep_opt *grep_opt = opt->value;
 633         int value;
 634         const char *endp;
 635
 636         if (unset) {
 637                 grep_opt->pre_context = grep_opt->post_context = 0;
 638                 return 0;
 639         }
 640         value = strtol(arg, (char **)&endp, 10);
 641         if (*endp) {
 642                 return error("switch `%c' expects a numerical value",
 643                              opt->short_name);
 644         }
 645         grep_opt->pre_context = grep_opt->post_context = value;
 646         return 0;
 647 }
 648
 649 static int file_callback(const struct option *opt, const char *arg, int unset)
 650 {
 651         struct grep_opt *grep_opt = opt->value;
 652         FILE *patterns;
 653         int lno = 0;
 654         struct strbuf sb = STRBUF_INIT;
 655
 656         patterns = fopen(arg, "r");
 657         if (!patterns)
 658                 die_errno("cannot open '%s'", arg);
 659         while (strbuf_getline(&sb, patterns, '\n') == 0) {
 660                 /* ignore empty line like grep does */
 661                 if (sb.len == 0)
 662                         continue;
 663                 append_grep_pattern(grep_opt, strbuf_detach(&sb, NULL), arg,
 664                                     ++lno, GREP_PATTERN);
 665         }
 666         fclose(patterns);
 667         strbuf_release(&sb);
 668         return 0;
 669 }
 670
 671 static int not_callback(const struct option *opt, const char *arg, int unset)
 672 {
 673         struct grep_opt *grep_opt = opt->value;
 674         append_grep_pattern(grep_opt, "--not", "command line", 0, GREP_NOT);
 675         return 0;
 676 }
 677
 678 static int and_callback(const struct option *opt, const char *arg, int unset)
 679 {
 680         struct grep_opt *grep_opt = opt->value;
 681         append_grep_pattern(grep_opt, "--and", "command line", 0, GREP_AND);
 682         return 0;
 683 }
 684
 685 static int open_callback(const struct option *opt, const char *arg, int unset)
 686 {
 687         struct grep_opt *grep_opt = opt->value;
 688         append_grep_pattern(grep_opt, "(", "command line", 0, GREP_OPEN_PAREN);
 689         return 0;
 690 }
 691
 692 static int close_callback(const struct option *opt, const char *arg, int unset)
 693 {
 694         struct grep_opt *grep_opt = opt->value;
 695         append_grep_pattern(grep_opt, ")", "command line", 0, GREP_CLOSE_PAREN);
 696         return 0;
 697 }
 698
 699 static int pattern_callback(const struct option *opt, const char *arg,
 700                             int unset)
 701 {
 702         struct grep_opt *grep_opt = opt->value;
 703         append_grep_pattern(grep_opt, arg, "-e option", 0, GREP_PATTERN);
 704         return 0;
 705 }
 706
 707 static int help_callback(const struct option *opt, const char *arg, int unset)
 708 {
 709         return -1;
 710 }
 711
 712 int cmd_grep(int argc, const char **argv, const char *prefix)
 713 {
 714         int hit = 0;
 715         int cached = 0;
 716         int external_grep_allowed = 1;
 717         int seen_dashdash = 0;
 718         struct grep_opt opt;
 719         struct object_array list = { 0, 0, NULL };
 720         const char **paths = NULL;
 721         int i;
 722         int dummy;
 723         struct option options[] = {
 724                 OPT_BOOLEAN(0, "cached", &cached,
 725                         "search in index instead of in the work tree"),
 726                 OPT_GROUP(""),
 727                 OPT_BOOLEAN('v', "invert-match", &opt.invert,
 728                         "show non-matching lines"),
 729                 OPT_BOOLEAN('i', "ignore-case", &opt.ignore_case,
 730                         "case insensitive matching"),
 731                 OPT_BOOLEAN('w', "word-regexp", &opt.word_regexp,
 732                         "match patterns only at word boundaries"),
 733                 OPT_SET_INT('a', "text", &opt.binary,
 734                         "process binary files as text", GREP_BINARY_TEXT),
 735                 OPT_SET_INT('I', NULL, &opt.binary,
 736                         "don't match patterns in binary files",
 737                         GREP_BINARY_NOMATCH),
 738                 { OPTION_INTEGER, 0, "max-depth", &opt.max_depth, "depth",
 739                         "descend at most <depth> levels", PARSE_OPT_NONEG,
 740                         NULL, 1 },
 741                 OPT_GROUP(""),
 742                 OPT_BIT('E', "extended-regexp", &opt.regflags,
 743                         "use extended POSIX regular expressions", REG_EXTENDED),
 744                 OPT_NEGBIT('G', "basic-regexp", &opt.regflags,
 745                         "use basic POSIX regular expressions (default)",
 746                         REG_EXTENDED),
 747                 OPT_BOOLEAN('F', "fixed-strings", &opt.fixed,
 748                         "interpret patterns as fixed strings"),
 749                 OPT_GROUP(""),
 750                 OPT_BOOLEAN('n', NULL, &opt.linenum, "show line numbers"),
 751                 OPT_NEGBIT('h', NULL, &opt.pathname, "don't show filenames", 1),
 752                 OPT_BIT('H', NULL, &opt.pathname, "show filenames", 1),
 753                 OPT_NEGBIT(0, "full-name", &opt.relative,
 754                         "show filenames relative to top directory", 1),
 755                 OPT_BOOLEAN('l', "files-with-matches", &opt.name_only,
 756                         "show only filenames instead of matching lines"),
 757                 OPT_BOOLEAN(0, "name-only", &opt.name_only,
 758                         "synonym for --files-with-matches"),
 759                 OPT_BOOLEAN('L', "files-without-match",
 760                         &opt.unmatch_name_only,
 761                         "show only the names of files without match"),
 762                 OPT_BOOLEAN('z', "null", &opt.null_following_name,
 763                         "print NUL after filenames"),
 764                 OPT_BOOLEAN('c', "count", &opt.count,
 765                         "show the number of matches instead of matching lines"),
 766                 OPT_SET_INT(0, "color", &opt.color, "highlight matches", 1),
 767                 OPT_GROUP(""),
 768                 OPT_CALLBACK('C', NULL, &opt, "n",
 769                         "show <n> context lines before and after matches",
 770                         context_callback),
 771                 OPT_INTEGER('B', NULL, &opt.pre_context,
 772                         "show <n> context lines before matches"),
 773                 OPT_INTEGER('A', NULL, &opt.post_context,
 774                         "show <n> context lines after matches"),
 775                 OPT_NUMBER_CALLBACK(&opt, "shortcut for -C NUM",
 776                         context_callback),
 777                 OPT_BOOLEAN('p', "show-function", &opt.funcname,
 778                         "show a line with the function name before matches"),
 779                 OPT_GROUP(""),
 780                 OPT_CALLBACK('f', NULL, &opt, "file",
 781                         "read patterns from file", file_callback),
 782                 { OPTION_CALLBACK, 'e', NULL, &opt, "pattern",
 783                         "match <pattern>", PARSE_OPT_NONEG, pattern_callback },
 784                 { OPTION_CALLBACK, 0, "and", &opt, NULL,
 785                   "combine patterns specified with -e",
 786                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, and_callback },
 787                 OPT_BOOLEAN(0, "or", &dummy, ""),
 788                 { OPTION_CALLBACK, 0, "not", &opt, NULL, "",
 789                   PARSE_OPT_NOARG | PARSE_OPT_NONEG, not_callback },
 790                 { OPTION_CALLBACK, '(', NULL, &opt, NULL, "",
 791                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 792                   open_callback },
 793                 { OPTION_CALLBACK, ')', NULL, &opt, NULL, "",
 794                   PARSE_OPT_NOARG | PARSE_OPT_NONEG | PARSE_OPT_NODASH,
 795                   close_callback },
 796                 OPT_BOOLEAN(0, "all-match", &opt.all_match,
 797                         "show only matches from files that match all patterns"),
 798                 OPT_GROUP(""),
 799 #if NO_EXTERNAL_GREP
 800                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed,
 801                         "allow calling of grep(1) (ignored by this build)"),
 802 #else
 803                 OPT_BOOLEAN(0, "ext-grep", &external_grep_allowed,
 804                         "allow calling of grep(1) (default)"),
 805 #endif
 806                 { OPTION_CALLBACK, 0, "help-all", &options, NULL, "show usage",
 807                   PARSE_OPT_HIDDEN | PARSE_OPT_NOARG, help_callback },
 808                 OPT_END()
 809         };
 810
 811         /*
 812          * 'git grep -h', unlike 'git grep -h <pattern>', is a request
 813          * to show usage information and exit.
 814          */
 815         if (argc == 2 && !strcmp(argv[1], "-h"))
 816                 usage_with_options(grep_usage, options);
 817
 818         memset(&opt, 0, sizeof(opt));
 819         opt.prefix = prefix;
 820         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 821         opt.relative = 1;
 822         opt.pathname = 1;
 823         opt.pattern_tail = &opt.pattern_list;
 824         opt.regflags = REG_NEWLINE;
 825         opt.max_depth = -1;
 826
 827         strcpy(opt.color_match, GIT_COLOR_RED GIT_COLOR_BOLD);
 828         opt.color = -1;
 829         git_config(grep_config, &opt);
 830         if (opt.color == -1)
 831                 opt.color = git_use_color_default;
 832
 833         /*
 834          * If there is no -- then the paths must exist in the working
 835          * tree.  If there is no explicit pattern specified with -e or
 836          * -f, we take the first unrecognized non option to be the
 837          * pattern, but then what follows it must be zero or more
 838          * valid refs up to the -- (if exists), and then existing
 839          * paths.  If there is an explicit pattern, then the first
 840          * unrecognized non option is the beginning of the refs list
 841          * that continues up to the -- (if exists), and then paths.
 842          */
 843         argc = parse_options(argc, argv, prefix, options, grep_usage,
 844                              PARSE_OPT_KEEP_DASHDASH |
 845                              PARSE_OPT_STOP_AT_NON_OPTION |
 846                              PARSE_OPT_NO_INTERNAL_HELP);
 847
 848         /* First unrecognized non-option token */
 849         if (argc > 0 && !opt.pattern_list) {
 850                 append_grep_pattern(&opt, argv[0], "command line", 0,
 851                                     GREP_PATTERN);
 852                 argv++;
 853                 argc--;
 854         }
 855
 856         if ((opt.color && !opt.color_external) || opt.funcname)
 857                 external_grep_allowed = 0;
 858         if (!opt.pattern_list)
 859                 die("no pattern given.");
 860         if (!opt.fixed && opt.ignore_case)
 861                 opt.regflags |= REG_ICASE;
 862         if ((opt.regflags != REG_NEWLINE) && opt.fixed)
 863                 die("cannot mix --fixed-strings and regexp");
 864         compile_grep_patterns(&opt);
 865
 866         /* Check revs and then paths */
 867         for (i = 0; i < argc; i++) {
 868                 const char *arg = argv[i];
 869                 unsigned char sha1[20];
 870                 /* Is it a rev? */
 871                 if (!get_sha1(arg, sha1)) {
 872                         struct object *object = parse_object(sha1);
 873                         if (!object)
 874                                 die("bad object %s", arg);
 875                         add_object_array(object, arg, &list);
 876                         continue;
 877                 }
 878                 if (!strcmp(arg, "--")) {
 879                         i++;
 880                         seen_dashdash = 1;
 881                 }
 882                 break;
 883         }
 884
 885         /* The rest are paths */
 886         if (!seen_dashdash) {
 887                 int j;
 888                 for (j = i; j < argc; j++)
 889                         verify_filename(prefix, argv[j]);
 890         }
 891
 892         if (i < argc)
 893                 paths = get_pathspec(prefix, argv + i);
 894         else if (prefix) {
 895                 paths = xcalloc(2, sizeof(const char *));
 896                 paths[0] = prefix;
 897                 paths[1] = NULL;
 898         }
 899
 900         if (!list.nr) {
 901                 if (!cached)
 902                         setup_work_tree();
 903                 return !grep_cache(&opt, paths, cached, external_grep_allowed);
 904         }
 905
 906         if (cached)
 907                 die("both --cached and trees are given.");
 908
 909         for (i = 0; i < list.nr; i++) {
 910                 struct object *real_obj;
 911                 real_obj = deref_tag(list.objects[i].item, NULL, 0);
 912                 if (grep_object(&opt, paths, real_obj, list.objects[i].name))
 913                         hit = 1;
 914         }
 915         free_grep_patterns(&opt);
 916         return !hit;
 917 }