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 "grep.h"
  14
  15 #ifndef NO_EXTERNAL_GREP
  16 #ifdef __unix__
  17 #define NO_EXTERNAL_GREP 0
  18 #else
  19 #define NO_EXTERNAL_GREP 1
  20 #endif
  21 #endif
  22
  23 static int builtin_grep;
  24
  25 static int grep_config(const char *var, const char *value, void *cb)
  26 {
  27         struct grep_opt *opt = cb;
  28
  29         if (!strcmp(var, "color.grep")) {
  30                 opt->color = git_config_colorbool(var, value, -1);
  31                 return 0;
  32         }
  33         if (!strcmp(var, "color.grep.external"))
  34                 return git_config_string(&(opt->color_external), var, value);
  35         if (!strcmp(var, "color.grep.match")) {
  36                 if (!value)
  37                         return config_error_nonbool(var);
  38                 color_parse(value, var, opt->color_match);
  39                 return 0;
  40         }
  41         return git_color_default_config(var, value, cb);
  42 }
  43
  44 /*
  45  * git grep pathspecs are somewhat different from diff-tree pathspecs;
  46  * pathname wildcards are allowed.
  47  */
  48 static int pathspec_matches(const char **paths, const char *name)
  49 {
  50         int namelen, i;
  51         if (!paths || !*paths)
  52                 return 1;
  53         namelen = strlen(name);
  54         for (i = 0; paths[i]; i++) {
  55                 const char *match = paths[i];
  56                 int matchlen = strlen(match);
  57                 const char *cp, *meta;
  58
  59                 if (!matchlen ||
  60                     ((matchlen <= namelen) &&
  61                      !strncmp(name, match, matchlen) &&
  62                      (match[matchlen-1] == '/' ||
  63                       name[matchlen] == '\0' || name[matchlen] == '/')))
  64                         return 1;
  65                 if (!fnmatch(match, name, 0))
  66                         return 1;
  67                 if (name[namelen-1] != '/')
  68                         continue;
  69
  70                 /* We are being asked if the directory ("name") is worth
  71                  * descending into.
  72                  *
  73                  * Find the longest leading directory name that does
  74                  * not have metacharacter in the pathspec; the name
  75                  * we are looking at must overlap with that directory.
  76                  */
  77                 for (cp = match, meta = NULL; cp - match < matchlen; cp++) {
  78                         char ch = *cp;
  79                         if (ch == '*' || ch == '[' || ch == '?') {
  80                                 meta = cp;
  81                                 break;
  82                         }
  83                 }
  84                 if (!meta)
  85                         meta = cp; /* fully literal */
  86
  87                 if (namelen <= meta - match) {
  88                         /* Looking at "Documentation/" and
  89                          * the pattern says "Documentation/howto/", or
  90                          * "Documentation/diff*.txt".  The name we
  91                          * have should match prefix.
  92                          */
  93                         if (!memcmp(match, name, namelen))
  94                                 return 1;
  95                         continue;
  96                 }
  97
  98                 if (meta - match < namelen) {
  99                         /* Looking at "Documentation/howto/" and
 100                          * the pattern says "Documentation/h*";
 101                          * match up to "Do.../h"; this avoids descending
 102                          * into "Documentation/technical/".
 103                          */
 104                         if (!memcmp(match, name, meta - match))
 105                                 return 1;
 106                         continue;
 107                 }
 108         }
 109         return 0;
 110 }
 111
 112 static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1, const char *name, int tree_name_len)
 113 {
 114         unsigned long size;
 115         char *data;
 116         enum object_type type;
 117         char *to_free = NULL;
 118         int hit;
 119
 120         data = read_sha1_file(sha1, &type, &size);
 121         if (!data) {
 122                 error("'%s': unable to read %s", name, sha1_to_hex(sha1));
 123                 return 0;
 124         }
 125         if (opt->relative && opt->prefix_length) {
 126                 static char name_buf[PATH_MAX];
 127                 char *cp;
 128                 int name_len = strlen(name) - opt->prefix_length + 1;
 129
 130                 if (!tree_name_len)
 131                         name += opt->prefix_length;
 132                 else {
 133                         if (ARRAY_SIZE(name_buf) <= name_len)
 134                                 cp = to_free = xmalloc(name_len);
 135                         else
 136                                 cp = name_buf;
 137                         memcpy(cp, name, tree_name_len);
 138                         strcpy(cp + tree_name_len,
 139                                name + tree_name_len + opt->prefix_length);
 140                         name = cp;
 141                 }
 142         }
 143         hit = grep_buffer(opt, name, data, size);
 144         free(data);
 145         free(to_free);
 146         return hit;
 147 }
 148
 149 static int grep_file(struct grep_opt *opt, const char *filename)
 150 {
 151         struct stat st;
 152         int i;
 153         char *data;
 154         size_t sz;
 155
 156         if (lstat(filename, &st) < 0) {
 157         err_ret:
 158                 if (errno != ENOENT)
 159                         error("'%s': %s", filename, strerror(errno));
 160                 return 0;
 161         }
 162         if (!st.st_size)
 163                 return 0; /* empty file -- no grep hit */
 164         if (!S_ISREG(st.st_mode))
 165                 return 0;
 166         sz = xsize_t(st.st_size);
 167         i = open(filename, O_RDONLY);
 168         if (i < 0)
 169                 goto err_ret;
 170         data = xmalloc(sz + 1);
 171         if (st.st_size != read_in_full(i, data, sz)) {
 172                 error("'%s': short read %s", filename, strerror(errno));
 173                 close(i);
 174                 free(data);
 175                 return 0;
 176         }
 177         close(i);
 178         if (opt->relative && opt->prefix_length)
 179                 filename += opt->prefix_length;
 180         i = grep_buffer(opt, filename, data, sz);
 181         free(data);
 182         return i;
 183 }
 184
 185 #if !NO_EXTERNAL_GREP
 186 static int exec_grep(int argc, const char **argv)
 187 {
 188         pid_t pid;
 189         int status;
 190
 191         argv[argc] = NULL;
 192         pid = fork();
 193         if (pid < 0)
 194                 return pid;
 195         if (!pid) {
 196                 execvp("grep", (char **) argv);
 197                 exit(255);
 198         }
 199         while (waitpid(pid, &status, 0) < 0) {
 200                 if (errno == EINTR)
 201                         continue;
 202                 return -1;
 203         }
 204         if (WIFEXITED(status)) {
 205                 if (!WEXITSTATUS(status))
 206                         return 1;
 207                 return 0;
 208         }
 209         return -1;
 210 }
 211
 212 #define MAXARGS 1000
 213 #define ARGBUF 4096
 214 #define push_arg(a) do { \
 215         if (nr < MAXARGS) argv[nr++] = (a); \
 216         else die("maximum number of args exceeded"); \
 217         } while (0)
 218
 219 /*
 220  * If you send a singleton filename to grep, it does not give
 221  * the name of the file.  GNU grep has "-H" but we would want
 222  * that behaviour in a portable way.
 223  *
 224  * So we keep two pathnames in argv buffer unsent to grep in
 225  * the main loop if we need to do more than one grep.
 226  */
 227 static int flush_grep(struct grep_opt *opt,
 228                       int argc, int arg0, const char **argv, int *kept)
 229 {
 230         int status;
 231         int count = argc - arg0;
 232         const char *kept_0 = NULL;
 233
 234         if (count <= 2) {
 235                 /*
 236                  * Because we keep at least 2 paths in the call from
 237                  * the main loop (i.e. kept != NULL), and MAXARGS is
 238                  * far greater than 2, this usually is a call to
 239                  * conclude the grep.  However, the user could attempt
 240                  * to overflow the argv buffer by giving too many
 241                  * options to leave very small number of real
 242                  * arguments even for the call in the main loop.
 243                  */
 244                 if (kept)
 245                         die("insanely many options to grep");
 246
 247                 /*
 248                  * If we have two or more paths, we do not have to do
 249                  * anything special, but we need to push /dev/null to
 250                  * get "-H" behaviour of GNU grep portably but when we
 251                  * are not doing "-l" nor "-L" nor "-c".
 252                  */
 253                 if (count == 1 &&
 254                     !opt->name_only &&
 255                     !opt->unmatch_name_only &&
 256                     !opt->count) {
 257                         argv[argc++] = "/dev/null";
 258                         argv[argc] = NULL;
 259                 }
 260         }
 261
 262         else if (kept) {
 263                 /*
 264                  * Called because we found many paths and haven't finished
 265                  * iterating over the cache yet.  We keep two paths
 266                  * for the concluding call.  argv[argc-2] and argv[argc-1]
 267                  * has the last two paths, so save the first one away,
 268                  * replace it with NULL while sending the list to grep,
 269                  * and recover them after we are done.
 270                  */
 271                 *kept = 2;
 272                 kept_0 = argv[argc-2];
 273                 argv[argc-2] = NULL;
 274                 argc -= 2;
 275         }
 276
 277         status = exec_grep(argc, argv);
 278
 279         if (kept_0) {
 280                 /*
 281                  * Then recover them.  Now the last arg is beyond the
 282                  * terminating NULL which is at argc, and the second
 283                  * from the last is what we saved away in kept_0
 284                  */
 285                 argv[arg0++] = kept_0;
 286                 argv[arg0] = argv[argc+1];
 287         }
 288         return status;
 289 }
 290
 291 static void grep_add_color(struct strbuf *sb, const char *escape_seq)
 292 {
 293         size_t orig_len = sb->len;
 294
 295         while (*escape_seq) {
 296                 if (*escape_seq == 'm')
 297                         strbuf_addch(sb, ';');
 298                 else if (*escape_seq != '\033' && *escape_seq  != '[')
 299                         strbuf_addch(sb, *escape_seq);
 300                 escape_seq++;
 301         }
 302         if (sb->len > orig_len && sb->buf[sb->len - 1] == ';')
 303                 strbuf_setlen(sb, sb->len - 1);
 304 }
 305
 306 static int external_grep(struct grep_opt *opt, const char **paths, int cached)
 307 {
 308         int i, nr, argc, hit, len, status;
 309         const char *argv[MAXARGS+1];
 310         char randarg[ARGBUF];
 311         char *argptr = randarg;
 312         struct grep_pat *p;
 313
 314         if (opt->extended || (opt->relative && opt->prefix_length))
 315                 return -1;
 316         len = nr = 0;
 317         push_arg("grep");
 318         if (opt->fixed)
 319                 push_arg("-F");
 320         if (opt->linenum)
 321                 push_arg("-n");
 322         if (!opt->pathname)
 323                 push_arg("-h");
 324         if (opt->regflags & REG_EXTENDED)
 325                 push_arg("-E");
 326         if (opt->regflags & REG_ICASE)
 327                 push_arg("-i");
 328         if (opt->binary == GREP_BINARY_NOMATCH)
 329                 push_arg("-I");
 330         if (opt->word_regexp)
 331                 push_arg("-w");
 332         if (opt->name_only)
 333                 push_arg("-l");
 334         if (opt->unmatch_name_only)
 335                 push_arg("-L");
 336         if (opt->null_following_name)
 337                 /* in GNU grep git's "-z" translates to "-Z" */
 338                 push_arg("-Z");
 339         if (opt->count)
 340                 push_arg("-c");
 341         if (opt->post_context || opt->pre_context) {
 342                 if (opt->post_context != opt->pre_context) {
 343                         if (opt->pre_context) {
 344                                 push_arg("-B");
 345                                 len += snprintf(argptr, sizeof(randarg)-len,
 346                                                 "%u", opt->pre_context) + 1;
 347                                 if (sizeof(randarg) <= len)
 348                                         die("maximum length of args exceeded");
 349                                 push_arg(argptr);
 350                                 argptr += len;
 351                         }
 352                         if (opt->post_context) {
 353                                 push_arg("-A");
 354                                 len += snprintf(argptr, sizeof(randarg)-len,
 355                                                 "%u", opt->post_context) + 1;
 356                                 if (sizeof(randarg) <= len)
 357                                         die("maximum length of args exceeded");
 358                                 push_arg(argptr);
 359                                 argptr += len;
 360                         }
 361                 }
 362                 else {
 363                         push_arg("-C");
 364                         len += snprintf(argptr, sizeof(randarg)-len,
 365                                         "%u", opt->post_context) + 1;
 366                         if (sizeof(randarg) <= len)
 367                                 die("maximum length of args exceeded");
 368                         push_arg(argptr);
 369                         argptr += len;
 370                 }
 371         }
 372         for (p = opt->pattern_list; p; p = p->next) {
 373                 push_arg("-e");
 374                 push_arg(p->pattern);
 375         }
 376         if (opt->color) {
 377                 struct strbuf sb = STRBUF_INIT;
 378
 379                 grep_add_color(&sb, opt->color_match);
 380                 setenv("GREP_COLOR", sb.buf, 1);
 381
 382                 strbuf_reset(&sb);
 383                 strbuf_addstr(&sb, "mt=");
 384                 grep_add_color(&sb, opt->color_match);
 385                 strbuf_addstr(&sb, ":sl=:cx=:fn=:ln=:bn=:se=");
 386                 setenv("GREP_COLORS", sb.buf, 1);
 387
 388                 strbuf_release(&sb);
 389
 390                 if (opt->color_external && strlen(opt->color_external) > 0)
 391                         push_arg(opt->color_external);
 392         }
 393
 394         hit = 0;
 395         argc = nr;
 396         for (i = 0; i < active_nr; i++) {
 397                 struct cache_entry *ce = active_cache[i];
 398                 char *name;
 399                 int kept;
 400                 if (!S_ISREG(ce->ce_mode))
 401                         continue;
 402                 if (!pathspec_matches(paths, ce->name))
 403                         continue;
 404                 name = ce->name;
 405                 if (name[0] == '-') {
 406                         int len = ce_namelen(ce);
 407                         name = xmalloc(len + 3);
 408                         memcpy(name, "./", 2);
 409                         memcpy(name + 2, ce->name, len + 1);
 410                 }
 411                 argv[argc++] = name;
 412                 if (MAXARGS <= argc) {
 413                         status = flush_grep(opt, argc, nr, argv, &kept);
 414                         if (0 < status)
 415                                 hit = 1;
 416                         argc = nr + kept;
 417                 }
 418                 if (ce_stage(ce)) {
 419                         do {
 420                                 i++;
 421                         } while (i < active_nr &&
 422                                  !strcmp(ce->name, active_cache[i]->name));
 423                         i--; /* compensate for loop control */
 424                 }
 425         }
 426         if (argc > nr) {
 427                 status = flush_grep(opt, argc, nr, argv, NULL);
 428                 if (0 < status)
 429                         hit = 1;
 430         }
 431         return hit;
 432 }
 433 #endif
 434
 435 static int grep_cache(struct grep_opt *opt, const char **paths, int cached)
 436 {
 437         int hit = 0;
 438         int nr;
 439         read_cache();
 440
 441 #if !NO_EXTERNAL_GREP
 442         /*
 443          * Use the external "grep" command for the case where
 444          * we grep through the checked-out files. It tends to
 445          * be a lot more optimized
 446          */
 447         if (!cached && !builtin_grep) {
 448                 hit = external_grep(opt, paths, cached);
 449                 if (hit >= 0)
 450                         return hit;
 451         }
 452 #endif
 453
 454         for (nr = 0; nr < active_nr; nr++) {
 455                 struct cache_entry *ce = active_cache[nr];
 456                 if (!S_ISREG(ce->ce_mode))
 457                         continue;
 458                 if (!pathspec_matches(paths, ce->name))
 459                         continue;
 460                 /*
 461                  * If CE_VALID is on, we assume worktree file and its cache entry
 462                  * are identical, even if worktree file has been modified, so use
 463                  * cache version instead
 464                  */
 465                 if (cached || (ce->ce_flags & CE_VALID)) {
 466                         if (ce_stage(ce))
 467                                 continue;
 468                         hit |= grep_sha1(opt, ce->sha1, ce->name, 0);
 469                 }
 470                 else
 471                         hit |= grep_file(opt, ce->name);
 472                 if (ce_stage(ce)) {
 473                         do {
 474                                 nr++;
 475                         } while (nr < active_nr &&
 476                                  !strcmp(ce->name, active_cache[nr]->name));
 477                         nr--; /* compensate for loop control */
 478                 }
 479         }
 480         free_grep_patterns(opt);
 481         return hit;
 482 }
 483
 484 static int grep_tree(struct grep_opt *opt, const char **paths,
 485                      struct tree_desc *tree,
 486                      const char *tree_name, const char *base)
 487 {
 488         int len;
 489         int hit = 0;
 490         struct name_entry entry;
 491         char *down;
 492         int tn_len = strlen(tree_name);
 493         struct strbuf pathbuf;
 494
 495         strbuf_init(&pathbuf, PATH_MAX + tn_len);
 496
 497         if (tn_len) {
 498                 strbuf_add(&pathbuf, tree_name, tn_len);
 499                 strbuf_addch(&pathbuf, ':');
 500                 tn_len = pathbuf.len;
 501         }
 502         strbuf_addstr(&pathbuf, base);
 503         len = pathbuf.len;
 504
 505         while (tree_entry(tree, &entry)) {
 506                 int te_len = tree_entry_len(entry.path, entry.sha1);
 507                 pathbuf.len = len;
 508                 strbuf_add(&pathbuf, entry.path, te_len);
 509
 510                 if (S_ISDIR(entry.mode))
 511                         /* Match "abc/" against pathspec to
 512                          * decide if we want to descend into "abc"
 513                          * directory.
 514                          */
 515                         strbuf_addch(&pathbuf, '/');
 516
 517                 down = pathbuf.buf + tn_len;
 518                 if (!pathspec_matches(paths, down))
 519                         ;
 520                 else if (S_ISREG(entry.mode))
 521                         hit |= grep_sha1(opt, entry.sha1, pathbuf.buf, tn_len);
 522                 else if (S_ISDIR(entry.mode)) {
 523                         enum object_type type;
 524                         struct tree_desc sub;
 525                         void *data;
 526                         unsigned long size;
 527
 528                         data = read_sha1_file(entry.sha1, &type, &size);
 529                         if (!data)
 530                                 die("unable to read tree (%s)",
 531                                     sha1_to_hex(entry.sha1));
 532                         init_tree_desc(&sub, data, size);
 533                         hit |= grep_tree(opt, paths, &sub, tree_name, down);
 534                         free(data);
 535                 }
 536         }
 537         strbuf_release(&pathbuf);
 538         return hit;
 539 }
 540
 541 static int grep_object(struct grep_opt *opt, const char **paths,
 542                        struct object *obj, const char *name)
 543 {
 544         if (obj->type == OBJ_BLOB)
 545                 return grep_sha1(opt, obj->sha1, name, 0);
 546         if (obj->type == OBJ_COMMIT || obj->type == OBJ_TREE) {
 547                 struct tree_desc tree;
 548                 void *data;
 549                 unsigned long size;
 550                 int hit;
 551                 data = read_object_with_reference(obj->sha1, tree_type,
 552                                                   &size, NULL);
 553                 if (!data)
 554                         die("unable to read tree (%s)", sha1_to_hex(obj->sha1));
 555                 init_tree_desc(&tree, data, size);
 556                 hit = grep_tree(opt, paths, &tree, name, "");
 557                 free(data);
 558                 return hit;
 559         }
 560         die("unable to grep from object of type %s", typename(obj->type));
 561 }
 562
 563 static const char builtin_grep_usage[] =
 564 "git grep <option>* [-e] <pattern> <rev>* [[--] <path>...]";
 565
 566 static const char emsg_invalid_context_len[] =
 567 "%s: invalid context length argument";
 568 static const char emsg_missing_context_len[] =
 569 "missing context length argument";
 570 static const char emsg_missing_argument[] =
 571 "option requires an argument -%s";
 572
 573 int cmd_grep(int argc, const char **argv, const char *prefix)
 574 {
 575         int hit = 0;
 576         int cached = 0;
 577         int seen_dashdash = 0;
 578         struct grep_opt opt;
 579         struct object_array list = { 0, 0, NULL };
 580         const char **paths = NULL;
 581         int i;
 582
 583         memset(&opt, 0, sizeof(opt));
 584         opt.prefix_length = (prefix && *prefix) ? strlen(prefix) : 0;
 585         opt.relative = 1;
 586         opt.pathname = 1;
 587         opt.pattern_tail = &opt.pattern_list;
 588         opt.regflags = REG_NEWLINE;
 589
 590         strcpy(opt.color_match, GIT_COLOR_RED GIT_COLOR_BOLD);
 591         opt.color = -1;
 592         git_config(grep_config, &opt);
 593         if (opt.color == -1)
 594                 opt.color = git_use_color_default;
 595
 596         /*
 597          * If there is no -- then the paths must exist in the working
 598          * tree.  If there is no explicit pattern specified with -e or
 599          * -f, we take the first unrecognized non option to be the
 600          * pattern, but then what follows it must be zero or more
 601          * valid refs up to the -- (if exists), and then existing
 602          * paths.  If there is an explicit pattern, then the first
 603          * unrecognized non option is the beginning of the refs list
 604          * that continues up to the -- (if exists), and then paths.
 605          */
 606
 607         while (1 < argc) {
 608                 const char *arg = argv[1];
 609                 argc--; argv++;
 610                 if (!strcmp("--cached", arg)) {
 611                         cached = 1;
 612                         continue;
 613                 }
 614                 if (!strcmp("--no-ext-grep", arg)) {
 615                         builtin_grep = 1;
 616                         continue;
 617                 }
 618                 if (!strcmp("-a", arg) ||
 619                     !strcmp("--text", arg)) {
 620                         opt.binary = GREP_BINARY_TEXT;
 621                         continue;
 622                 }
 623                 if (!strcmp("-i", arg) ||
 624                     !strcmp("--ignore-case", arg)) {
 625                         opt.regflags |= REG_ICASE;
 626                         continue;
 627                 }
 628                 if (!strcmp("-I", arg)) {
 629                         opt.binary = GREP_BINARY_NOMATCH;
 630                         continue;
 631                 }
 632                 if (!strcmp("-v", arg) ||
 633                     !strcmp("--invert-match", arg)) {
 634                         opt.invert = 1;
 635                         continue;
 636                 }
 637                 if (!strcmp("-E", arg) ||
 638                     !strcmp("--extended-regexp", arg)) {
 639                         opt.regflags |= REG_EXTENDED;
 640                         continue;
 641                 }
 642                 if (!strcmp("-F", arg) ||
 643                     !strcmp("--fixed-strings", arg)) {
 644                         opt.fixed = 1;
 645                         continue;
 646                 }
 647                 if (!strcmp("-G", arg) ||
 648                     !strcmp("--basic-regexp", arg)) {
 649                         opt.regflags &= ~REG_EXTENDED;
 650                         continue;
 651                 }
 652                 if (!strcmp("-n", arg)) {
 653                         opt.linenum = 1;
 654                         continue;
 655                 }
 656                 if (!strcmp("-h", arg)) {
 657                         opt.pathname = 0;
 658                         continue;
 659                 }
 660                 if (!strcmp("-H", arg)) {
 661                         opt.pathname = 1;
 662                         continue;
 663                 }
 664                 if (!strcmp("-l", arg) ||
 665                     !strcmp("--name-only", arg) ||
 666                     !strcmp("--files-with-matches", arg)) {
 667                         opt.name_only = 1;
 668                         continue;
 669                 }
 670                 if (!strcmp("-L", arg) ||
 671                     !strcmp("--files-without-match", arg)) {
 672                         opt.unmatch_name_only = 1;
 673                         continue;
 674                 }
 675                 if (!strcmp("-z", arg) ||
 676                     !strcmp("--null", arg)) {
 677                         opt.null_following_name = 1;
 678                         continue;
 679                 }
 680                 if (!strcmp("-c", arg) ||
 681                     !strcmp("--count", arg)) {
 682                         opt.count = 1;
 683                         continue;
 684                 }
 685                 if (!strcmp("-w", arg) ||
 686                     !strcmp("--word-regexp", arg)) {
 687                         opt.word_regexp = 1;
 688                         continue;
 689                 }
 690                 if (!prefixcmp(arg, "-A") ||
 691                     !prefixcmp(arg, "-B") ||
 692                     !prefixcmp(arg, "-C") ||
 693                     (arg[0] == '-' && '1' <= arg[1] && arg[1] <= '9')) {
 694                         unsigned num;
 695                         const char *scan;
 696                         switch (arg[1]) {
 697                         case 'A': case 'B': case 'C':
 698                                 if (!arg[2]) {
 699                                         if (argc <= 1)
 700                                                 die(emsg_missing_context_len);
 701                                         scan = *++argv;
 702                                         argc--;
 703                                 }
 704                                 else
 705                                         scan = arg + 2;
 706                                 break;
 707                         default:
 708                                 scan = arg + 1;
 709                                 break;
 710                         }
 711                         if (strtoul_ui(scan, 10, &num))
 712                                 die(emsg_invalid_context_len, scan);
 713                         switch (arg[1]) {
 714                         case 'A':
 715                                 opt.post_context = num;
 716                                 break;
 717                         default:
 718                         case 'C':
 719                                 opt.post_context = num;
 720                         case 'B':
 721                                 opt.pre_context = num;
 722                                 break;
 723                         }
 724                         continue;
 725                 }
 726                 if (!strcmp("-f", arg)) {
 727                         FILE *patterns;
 728                         int lno = 0;
 729                         char buf[1024];
 730                         if (argc <= 1)
 731                                 die(emsg_missing_argument, arg);
 732                         patterns = fopen(argv[1], "r");
 733                         if (!patterns)
 734                                 die("'%s': %s", argv[1], strerror(errno));
 735                         while (fgets(buf, sizeof(buf), patterns)) {
 736                                 int len = strlen(buf);
 737                                 if (len && buf[len-1] == '\n')
 738                                         buf[len-1] = 0;
 739                                 /* ignore empty line like grep does */
 740                                 if (!buf[0])
 741                                         continue;
 742                                 append_grep_pattern(&opt, xstrdup(buf),
 743                                                     argv[1], ++lno,
 744                                                     GREP_PATTERN);
 745                         }
 746                         fclose(patterns);
 747                         argv++;
 748                         argc--;
 749                         continue;
 750                 }
 751                 if (!strcmp("--not", arg)) {
 752                         append_grep_pattern(&opt, arg, "command line", 0,
 753                                             GREP_NOT);
 754                         continue;
 755                 }
 756                 if (!strcmp("--and", arg)) {
 757                         append_grep_pattern(&opt, arg, "command line", 0,
 758                                             GREP_AND);
 759                         continue;
 760                 }
 761                 if (!strcmp("--or", arg))
 762                         continue; /* no-op */
 763                 if (!strcmp("(", arg)) {
 764                         append_grep_pattern(&opt, arg, "command line", 0,
 765                                             GREP_OPEN_PAREN);
 766                         continue;
 767                 }
 768                 if (!strcmp(")", arg)) {
 769                         append_grep_pattern(&opt, arg, "command line", 0,
 770                                             GREP_CLOSE_PAREN);
 771                         continue;
 772                 }
 773                 if (!strcmp("--all-match", arg)) {
 774                         opt.all_match = 1;
 775                         continue;
 776                 }
 777                 if (!strcmp("-e", arg)) {
 778                         if (1 < argc) {
 779                                 append_grep_pattern(&opt, argv[1],
 780                                                     "-e option", 0,
 781                                                     GREP_PATTERN);
 782                                 argv++;
 783                                 argc--;
 784                                 continue;
 785                         }
 786                         die(emsg_missing_argument, arg);
 787                 }
 788                 if (!strcmp("--full-name", arg)) {
 789                         opt.relative = 0;
 790                         continue;
 791                 }
 792                 if (!strcmp("--color", arg)) {
 793                         opt.color = 1;
 794                         continue;
 795                 }
 796                 if (!strcmp("--no-color", arg)) {
 797                         opt.color = 0;
 798                         continue;
 799                 }
 800                 if (!strcmp("--", arg)) {
 801                         /* later processing wants to have this at argv[1] */
 802                         argv--;
 803                         argc++;
 804                         break;
 805                 }
 806                 if (*arg == '-')
 807                         usage(builtin_grep_usage);
 808
 809                 /* First unrecognized non-option token */
 810                 if (!opt.pattern_list) {
 811                         append_grep_pattern(&opt, arg, "command line", 0,
 812                                             GREP_PATTERN);
 813                         break;
 814                 }
 815                 else {
 816                         /* We are looking at the first path or rev;
 817                          * it is found at argv[1] after leaving the
 818                          * loop.
 819                          */
 820                         argc++; argv--;
 821                         break;
 822                 }
 823         }
 824
 825         if (opt.color && !opt.color_external)
 826                 builtin_grep = 1;
 827         if (!opt.pattern_list)
 828                 die("no pattern given.");
 829         if ((opt.regflags != REG_NEWLINE) && opt.fixed)
 830                 die("cannot mix --fixed-strings and regexp");
 831         compile_grep_patterns(&opt);
 832
 833         /* Check revs and then paths */
 834         for (i = 1; i < argc; i++) {
 835                 const char *arg = argv[i];
 836                 unsigned char sha1[20];
 837                 /* Is it a rev? */
 838                 if (!get_sha1(arg, sha1)) {
 839                         struct object *object = parse_object(sha1);
 840                         if (!object)
 841                                 die("bad object %s", arg);
 842                         add_object_array(object, arg, &list);
 843                         continue;
 844                 }
 845                 if (!strcmp(arg, "--")) {
 846                         i++;
 847                         seen_dashdash = 1;
 848                 }
 849                 break;
 850         }
 851
 852         /* The rest are paths */
 853         if (!seen_dashdash) {
 854                 int j;
 855                 for (j = i; j < argc; j++)
 856                         verify_filename(prefix, argv[j]);
 857         }
 858
 859         if (i < argc) {
 860                 paths = get_pathspec(prefix, argv + i);
 861                 if (opt.prefix_length && opt.relative) {
 862                         /* Make sure we do not get outside of paths */
 863                         for (i = 0; paths[i]; i++)
 864                                 if (strncmp(prefix, paths[i], opt.prefix_length))
 865                                         die("git grep: cannot generate relative filenames containing '..'");
 866                 }
 867         }
 868         else if (prefix) {
 869                 paths = xcalloc(2, sizeof(const char *));
 870                 paths[0] = prefix;
 871                 paths[1] = NULL;
 872         }
 873
 874         if (!list.nr) {
 875                 if (!cached)
 876                         setup_work_tree();
 877                 return !grep_cache(&opt, paths, cached);
 878         }
 879
 880         if (cached)
 881                 die("both --cached and trees are given.");
 882
 883         for (i = 0; i < list.nr; i++) {
 884                 struct object *real_obj;
 885                 real_obj = deref_tag(list.objects[i].item, NULL, 0);
 886                 if (grep_object(&opt, paths, real_obj, list.objects[i].name))
 887                         hit = 1;
 888         }
 889         free_grep_patterns(&opt);
 890         return !hit;
 891 }