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