builtin/cat-file.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #define USE_THE_INDEX_COMPATIBILITY_MACROS
   7 #include "cache.h"
   8 #include "config.h"
   9 #include "builtin.h"
  10 #include "diff.h"
  11 #include "parse-options.h"
  12 #include "userdiff.h"
  13 #include "streaming.h"
  14 #include "tree-walk.h"
  15 #include "sha1-array.h"
  16 #include "packfile.h"
  17 #include "object-store.h"
  18
  19 struct batch_options {
  20         int enabled;
  21         int follow_symlinks;
  22         int print_contents;
  23         int buffer_output;
  24         int all_objects;
  25         int unordered;
  26         int cmdmode; /* may be 'w' or 'c' for --filters or --textconv */
  27         const char *format;
  28 };
  29
  30 static const char *force_path;
  31
  32 static int filter_object(const char *path, unsigned mode,
  33                          const struct object_id *oid,
  34                          char **buf, unsigned long *size)
  35 {
  36         enum object_type type;
  37
  38         *buf = read_object_file(oid, &type, size);
  39         if (!*buf)
  40                 return error(_("cannot read object %s '%s'"),
  41                              oid_to_hex(oid), path);
  42         if ((type == OBJ_BLOB) && S_ISREG(mode)) {
  43                 struct strbuf strbuf = STRBUF_INIT;
  44                 if (convert_to_working_tree(&the_index, path, *buf, *size, &strbuf)) {
  45                         free(*buf);
  46                         *size = strbuf.len;
  47                         *buf = strbuf_detach(&strbuf, NULL);
  48                 }
  49         }
  50
  51         return 0;
  52 }
  53
  54 static int stream_blob(const struct object_id *oid)
  55 {
  56         if (stream_blob_to_fd(1, oid, NULL, 0))
  57                 die("unable to stream %s to stdout", oid_to_hex(oid));
  58         return 0;
  59 }
  60
  61 static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
  62                         int unknown_type)
  63 {
  64         struct object_id oid;
  65         enum object_type type;
  66         char *buf;
  67         unsigned long size;
  68         struct object_context obj_context;
  69         struct object_info oi = OBJECT_INFO_INIT;
  70         struct strbuf sb = STRBUF_INIT;
  71         unsigned flags = OBJECT_INFO_LOOKUP_REPLACE;
  72         const char *path = force_path;
  73
  74         if (unknown_type)
  75                 flags |= OBJECT_INFO_ALLOW_UNKNOWN_TYPE;
  76
  77         if (get_oid_with_context(the_repository, obj_name,
  78                                  GET_OID_RECORD_PATH,
  79                                  &oid, &obj_context))
  80                 die("Not a valid object name %s", obj_name);
  81
  82         if (!path)
  83                 path = obj_context.path;
  84         if (obj_context.mode == S_IFINVALID)
  85                 obj_context.mode = 0100644;
  86
  87         buf = NULL;
  88         switch (opt) {
  89         case 't':
  90                 oi.type_name = &sb;
  91                 if (oid_object_info_extended(the_repository, &oid, &oi, flags) < 0)
  92                         die("git cat-file: could not get object info");
  93                 if (sb.len) {
  94                         printf("%s\n", sb.buf);
  95                         strbuf_release(&sb);
  96                         return 0;
  97                 }
  98                 break;
  99
 100         case 's':
 101                 oi.sizep = &size;
 102                 if (oid_object_info_extended(the_repository, &oid, &oi, flags) < 0)
 103                         die("git cat-file: could not get object info");
 104                 printf("%"PRIuMAX"\n", (uintmax_t)size);
 105                 return 0;
 106
 107         case 'e':
 108                 return !has_object_file(&oid);
 109
 110         case 'w':
 111                 if (!path)
 112                         die("git cat-file --filters %s: <object> must be "
 113                             "<sha1:path>", obj_name);
 114
 115                 if (filter_object(path, obj_context.mode,
 116                                   &oid, &buf, &size))
 117                         return -1;
 118                 break;
 119
 120         case 'c':
 121                 if (!path)
 122                         die("git cat-file --textconv %s: <object> must be <sha1:path>",
 123                             obj_name);
 124
 125                 if (textconv_object(the_repository, path, obj_context.mode,
 126                                     &oid, 1, &buf, &size))
 127                         break;
 128                 /* else fallthrough */
 129
 130         case 'p':
 131                 type = oid_object_info(the_repository, &oid, NULL);
 132                 if (type < 0)
 133                         die("Not a valid object name %s", obj_name);
 134
 135                 /* custom pretty-print here */
 136                 if (type == OBJ_TREE) {
 137                         const char *ls_args[3] = { NULL };
 138                         ls_args[0] =  "ls-tree";
 139                         ls_args[1] =  obj_name;
 140                         return cmd_ls_tree(2, ls_args, NULL);
 141                 }
 142
 143                 if (type == OBJ_BLOB)
 144                         return stream_blob(&oid);
 145                 buf = read_object_file(&oid, &type, &size);
 146                 if (!buf)
 147                         die("Cannot read object %s", obj_name);
 148
 149                 /* otherwise just spit out the data */
 150                 break;
 151
 152         case 0:
 153                 if (type_from_string(exp_type) == OBJ_BLOB) {
 154                         struct object_id blob_oid;
 155                         if (oid_object_info(the_repository, &oid, NULL) == OBJ_TAG) {
 156                                 char *buffer = read_object_file(&oid, &type,
 157                                                                 &size);
 158                                 const char *target;
 159                                 if (!skip_prefix(buffer, "object ", &target) ||
 160                                     get_oid_hex(target, &blob_oid))
 161                                         die("%s not a valid tag", oid_to_hex(&oid));
 162                                 free(buffer);
 163                         } else
 164                                 oidcpy(&blob_oid, &oid);
 165
 166                         if (oid_object_info(the_repository, &blob_oid, NULL) == OBJ_BLOB)
 167                                 return stream_blob(&blob_oid);
 168                         /*
 169                          * we attempted to dereference a tag to a blob
 170                          * and failed; there may be new dereference
 171                          * mechanisms this code is not aware of.
 172                          * fall-back to the usual case.
 173                          */
 174                 }
 175                 buf = read_object_with_reference(the_repository,
 176                                                  &oid, exp_type, &size, NULL);
 177                 break;
 178
 179         default:
 180                 die("git cat-file: unknown option: %s", exp_type);
 181         }
 182
 183         if (!buf)
 184                 die("git cat-file %s: bad file", obj_name);
 185
 186         write_or_die(1, buf, size);
 187         free(buf);
 188         free(obj_context.path);
 189         return 0;
 190 }
 191
 192 struct expand_data {
 193         struct object_id oid;
 194         enum object_type type;
 195         unsigned long size;
 196         off_t disk_size;
 197         const char *rest;
 198         struct object_id delta_base_oid;
 199
 200         /*
 201          * If mark_query is true, we do not expand anything, but rather
 202          * just mark the object_info with items we wish to query.
 203          */
 204         int mark_query;
 205
 206         /*
 207          * Whether to split the input on whitespace before feeding it to
 208          * get_sha1; this is decided during the mark_query phase based on
 209          * whether we have a %(rest) token in our format.
 210          */
 211         int split_on_whitespace;
 212
 213         /*
 214          * After a mark_query run, this object_info is set up to be
 215          * passed to oid_object_info_extended. It will point to the data
 216          * elements above, so you can retrieve the response from there.
 217          */
 218         struct object_info info;
 219
 220         /*
 221          * This flag will be true if the requested batch format and options
 222          * don't require us to call oid_object_info, which can then be
 223          * optimized out.
 224          */
 225         unsigned skip_object_info : 1;
 226 };
 227
 228 static int is_atom(const char *atom, const char *s, int slen)
 229 {
 230         int alen = strlen(atom);
 231         return alen == slen && !memcmp(atom, s, alen);
 232 }
 233
 234 static void expand_atom(struct strbuf *sb, const char *atom, int len,
 235                         void *vdata)
 236 {
 237         struct expand_data *data = vdata;
 238
 239         if (is_atom("objectname", atom, len)) {
 240                 if (!data->mark_query)
 241                         strbuf_addstr(sb, oid_to_hex(&data->oid));
 242         } else if (is_atom("objecttype", atom, len)) {
 243                 if (data->mark_query)
 244                         data->info.typep = &data->type;
 245                 else
 246                         strbuf_addstr(sb, type_name(data->type));
 247         } else if (is_atom("objectsize", atom, len)) {
 248                 if (data->mark_query)
 249                         data->info.sizep = &data->size;
 250                 else
 251                         strbuf_addf(sb, "%"PRIuMAX , (uintmax_t)data->size);
 252         } else if (is_atom("objectsize:disk", atom, len)) {
 253                 if (data->mark_query)
 254                         data->info.disk_sizep = &data->disk_size;
 255                 else
 256                         strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
 257         } else if (is_atom("rest", atom, len)) {
 258                 if (data->mark_query)
 259                         data->split_on_whitespace = 1;
 260                 else if (data->rest)
 261                         strbuf_addstr(sb, data->rest);
 262         } else if (is_atom("deltabase", atom, len)) {
 263                 if (data->mark_query)
 264                         data->info.delta_base_sha1 = data->delta_base_oid.hash;
 265                 else
 266                         strbuf_addstr(sb,
 267                                       oid_to_hex(&data->delta_base_oid));
 268         } else
 269                 die("unknown format element: %.*s", len, atom);
 270 }
 271
 272 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 273 {
 274         const char *end;
 275
 276         if (*start != '(')
 277                 return 0;
 278         end = strchr(start + 1, ')');
 279         if (!end)
 280                 die("format element '%s' does not end in ')'", start);
 281
 282         expand_atom(sb, start + 1, end - start - 1, data);
 283
 284         return end - start + 1;
 285 }
 286
 287 static void batch_write(struct batch_options *opt, const void *data, int len)
 288 {
 289         if (opt->buffer_output) {
 290                 if (fwrite(data, 1, len, stdout) != len)
 291                         die_errno("unable to write to stdout");
 292         } else
 293                 write_or_die(1, data, len);
 294 }
 295
 296 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
 297 {
 298         const struct object_id *oid = &data->oid;
 299
 300         assert(data->info.typep);
 301
 302         if (data->type == OBJ_BLOB) {
 303                 if (opt->buffer_output)
 304                         fflush(stdout);
 305                 if (opt->cmdmode) {
 306                         char *contents;
 307                         unsigned long size;
 308
 309                         if (!data->rest)
 310                                 die("missing path for '%s'", oid_to_hex(oid));
 311
 312                         if (opt->cmdmode == 'w') {
 313                                 if (filter_object(data->rest, 0100644, oid,
 314                                                   &contents, &size))
 315                                         die("could not convert '%s' %s",
 316                                             oid_to_hex(oid), data->rest);
 317                         } else if (opt->cmdmode == 'c') {
 318                                 enum object_type type;
 319                                 if (!textconv_object(the_repository,
 320                                                      data->rest, 0100644, oid,
 321                                                      1, &contents, &size))
 322                                         contents = read_object_file(oid,
 323                                                                     &type,
 324                                                                     &size);
 325                                 if (!contents)
 326                                         die("could not convert '%s' %s",
 327                                             oid_to_hex(oid), data->rest);
 328                         } else
 329                                 BUG("invalid cmdmode: %c", opt->cmdmode);
 330                         batch_write(opt, contents, size);
 331                         free(contents);
 332                 } else {
 333                         stream_blob(oid);
 334                 }
 335         }
 336         else {
 337                 enum object_type type;
 338                 unsigned long size;
 339                 void *contents;
 340
 341                 contents = read_object_file(oid, &type, &size);
 342                 if (!contents)
 343                         die("object %s disappeared", oid_to_hex(oid));
 344                 if (type != data->type)
 345                         die("object %s changed type!?", oid_to_hex(oid));
 346                 if (data->info.sizep && size != data->size)
 347                         die("object %s changed size!?", oid_to_hex(oid));
 348
 349                 batch_write(opt, contents, size);
 350                 free(contents);
 351         }
 352 }
 353
 354 static void batch_object_write(const char *obj_name,
 355                                struct strbuf *scratch,
 356                                struct batch_options *opt,
 357                                struct expand_data *data)
 358 {
 359         if (!data->skip_object_info &&
 360             oid_object_info_extended(the_repository, &data->oid, &data->info,
 361                                      OBJECT_INFO_LOOKUP_REPLACE) < 0) {
 362                 printf("%s missing\n",
 363                        obj_name ? obj_name : oid_to_hex(&data->oid));
 364                 fflush(stdout);
 365                 return;
 366         }
 367
 368         strbuf_reset(scratch);
 369         strbuf_expand(scratch, opt->format, expand_format, data);
 370         strbuf_addch(scratch, '\n');
 371         batch_write(opt, scratch->buf, scratch->len);
 372
 373         if (opt->print_contents) {
 374                 print_object_or_die(opt, data);
 375                 batch_write(opt, "\n", 1);
 376         }
 377 }
 378
 379 static void batch_one_object(const char *obj_name,
 380                              struct strbuf *scratch,
 381                              struct batch_options *opt,
 382                              struct expand_data *data)
 383 {
 384         struct object_context ctx;
 385         int flags = opt->follow_symlinks ? GET_OID_FOLLOW_SYMLINKS : 0;
 386         enum get_oid_result result;
 387
 388         result = get_oid_with_context(the_repository, obj_name,
 389                                       flags, &data->oid, &ctx);
 390         if (result != FOUND) {
 391                 switch (result) {
 392                 case MISSING_OBJECT:
 393                         printf("%s missing\n", obj_name);
 394                         break;
 395                 case SHORT_NAME_AMBIGUOUS:
 396                         printf("%s ambiguous\n", obj_name);
 397                         break;
 398                 case DANGLING_SYMLINK:
 399                         printf("dangling %"PRIuMAX"\n%s\n",
 400                                (uintmax_t)strlen(obj_name), obj_name);
 401                         break;
 402                 case SYMLINK_LOOP:
 403                         printf("loop %"PRIuMAX"\n%s\n",
 404                                (uintmax_t)strlen(obj_name), obj_name);
 405                         break;
 406                 case NOT_DIR:
 407                         printf("notdir %"PRIuMAX"\n%s\n",
 408                                (uintmax_t)strlen(obj_name), obj_name);
 409                         break;
 410                 default:
 411                         BUG("unknown get_sha1_with_context result %d\n",
 412                                result);
 413                         break;
 414                 }
 415                 fflush(stdout);
 416                 return;
 417         }
 418
 419         if (ctx.mode == 0) {
 420                 printf("symlink %"PRIuMAX"\n%s\n",
 421                        (uintmax_t)ctx.symlink_path.len,
 422                        ctx.symlink_path.buf);
 423                 fflush(stdout);
 424                 return;
 425         }
 426
 427         batch_object_write(obj_name, scratch, opt, data);
 428 }
 429
 430 struct object_cb_data {
 431         struct batch_options *opt;
 432         struct expand_data *expand;
 433         struct oidset *seen;
 434         struct strbuf *scratch;
 435 };
 436
 437 static int batch_object_cb(const struct object_id *oid, void *vdata)
 438 {
 439         struct object_cb_data *data = vdata;
 440         oidcpy(&data->expand->oid, oid);
 441         batch_object_write(NULL, data->scratch, data->opt, data->expand);
 442         return 0;
 443 }
 444
 445 static int collect_loose_object(const struct object_id *oid,
 446                                 const char *path,
 447                                 void *data)
 448 {
 449         oid_array_append(data, oid);
 450         return 0;
 451 }
 452
 453 static int collect_packed_object(const struct object_id *oid,
 454                                  struct packed_git *pack,
 455                                  uint32_t pos,
 456                                  void *data)
 457 {
 458         oid_array_append(data, oid);
 459         return 0;
 460 }
 461
 462 static int batch_unordered_object(const struct object_id *oid, void *vdata)
 463 {
 464         struct object_cb_data *data = vdata;
 465
 466         if (oidset_insert(data->seen, oid))
 467                 return 0;
 468
 469         return batch_object_cb(oid, data);
 470 }
 471
 472 static int batch_unordered_loose(const struct object_id *oid,
 473                                  const char *path,
 474                                  void *data)
 475 {
 476         return batch_unordered_object(oid, data);
 477 }
 478
 479 static int batch_unordered_packed(const struct object_id *oid,
 480                                   struct packed_git *pack,
 481                                   uint32_t pos,
 482                                   void *data)
 483 {
 484         return batch_unordered_object(oid, data);
 485 }
 486
 487 static int batch_objects(struct batch_options *opt)
 488 {
 489         struct strbuf input = STRBUF_INIT;
 490         struct strbuf output = STRBUF_INIT;
 491         struct expand_data data;
 492         int save_warning;
 493         int retval = 0;
 494
 495         if (!opt->format)
 496                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
 497
 498         /*
 499          * Expand once with our special mark_query flag, which will prime the
 500          * object_info to be handed to oid_object_info_extended for each
 501          * object.
 502          */
 503         memset(&data, 0, sizeof(data));
 504         data.mark_query = 1;
 505         strbuf_expand(&output, opt->format, expand_format, &data);
 506         data.mark_query = 0;
 507         strbuf_release(&output);
 508         if (opt->cmdmode)
 509                 data.split_on_whitespace = 1;
 510
 511         if (opt->all_objects) {
 512                 struct object_info empty = OBJECT_INFO_INIT;
 513                 if (!memcmp(&data.info, &empty, sizeof(empty)))
 514                         data.skip_object_info = 1;
 515         }
 516
 517         /*
 518          * If we are printing out the object, then always fill in the type,
 519          * since we will want to decide whether or not to stream.
 520          */
 521         if (opt->print_contents)
 522                 data.info.typep = &data.type;
 523
 524         if (opt->all_objects) {
 525                 struct object_cb_data cb;
 526
 527                 if (repository_format_partial_clone)
 528                         warning("This repository has extensions.partialClone set. Some objects may not be loaded.");
 529
 530                 cb.opt = opt;
 531                 cb.expand = &data;
 532                 cb.scratch = &output;
 533
 534                 if (opt->unordered) {
 535                         struct oidset seen = OIDSET_INIT;
 536
 537                         cb.seen = &seen;
 538
 539                         for_each_loose_object(batch_unordered_loose, &cb, 0);
 540                         for_each_packed_object(batch_unordered_packed, &cb,
 541                                                FOR_EACH_OBJECT_PACK_ORDER);
 542
 543                         oidset_clear(&seen);
 544                 } else {
 545                         struct oid_array sa = OID_ARRAY_INIT;
 546
 547                         for_each_loose_object(collect_loose_object, &sa, 0);
 548                         for_each_packed_object(collect_packed_object, &sa, 0);
 549
 550                         oid_array_for_each_unique(&sa, batch_object_cb, &cb);
 551
 552                         oid_array_clear(&sa);
 553                 }
 554
 555                 strbuf_release(&output);
 556                 return 0;
 557         }
 558
 559         /*
 560          * We are going to call get_sha1 on a potentially very large number of
 561          * objects. In most large cases, these will be actual object sha1s. The
 562          * cost to double-check that each one is not also a ref (just so we can
 563          * warn) ends up dwarfing the actual cost of the object lookups
 564          * themselves. We can work around it by just turning off the warning.
 565          */
 566         save_warning = warn_on_object_refname_ambiguity;
 567         warn_on_object_refname_ambiguity = 0;
 568
 569         while (strbuf_getline(&input, stdin) != EOF) {
 570                 if (data.split_on_whitespace) {
 571                         /*
 572                          * Split at first whitespace, tying off the beginning
 573                          * of the string and saving the remainder (or NULL) in
 574                          * data.rest.
 575                          */
 576                         char *p = strpbrk(input.buf, " \t");
 577                         if (p) {
 578                                 while (*p && strchr(" \t", *p))
 579                                         *p++ = '\0';
 580                         }
 581                         data.rest = p;
 582                 }
 583
 584                 batch_one_object(input.buf, &output, opt, &data);
 585         }
 586
 587         strbuf_release(&input);
 588         strbuf_release(&output);
 589         warn_on_object_refname_ambiguity = save_warning;
 590         return retval;
 591 }
 592
 593 static const char * const cat_file_usage[] = {
 594         N_("git cat-file (-t [--allow-unknown-type] | -s [--allow-unknown-type] | -e | -p | <type> | --textconv | --filters) [--path=<path>] <object>"),
 595         N_("git cat-file (--batch | --batch-check) [--follow-symlinks] [--textconv | --filters]"),
 596         NULL
 597 };
 598
 599 static int git_cat_file_config(const char *var, const char *value, void *cb)
 600 {
 601         if (userdiff_config(var, value) < 0)
 602                 return -1;
 603
 604         return git_default_config(var, value, cb);
 605 }
 606
 607 static int batch_option_callback(const struct option *opt,
 608                                  const char *arg,
 609                                  int unset)
 610 {
 611         struct batch_options *bo = opt->value;
 612
 613         BUG_ON_OPT_NEG(unset);
 614
 615         if (bo->enabled) {
 616                 return error(_("only one batch option may be specified"));
 617         }
 618
 619         bo->enabled = 1;
 620         bo->print_contents = !strcmp(opt->long_name, "batch");
 621         bo->format = arg;
 622
 623         return 0;
 624 }
 625
 626 int cmd_cat_file(int argc, const char **argv, const char *prefix)
 627 {
 628         int opt = 0;
 629         const char *exp_type = NULL, *obj_name = NULL;
 630         struct batch_options batch = {0};
 631         int unknown_type = 0;
 632
 633         const struct option options[] = {
 634                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 635                 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
 636                 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
 637                 OPT_CMDMODE('e', NULL, &opt,
 638                             N_("exit with zero when there's no error"), 'e'),
 639                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 640                 OPT_CMDMODE(0, "textconv", &opt,
 641                             N_("for blob objects, run textconv on object's content"), 'c'),
 642                 OPT_CMDMODE(0, "filters", &opt,
 643                             N_("for blob objects, run filters on object's content"), 'w'),
 644                 OPT_STRING(0, "path", &force_path, N_("blob"),
 645                            N_("use a specific path for --textconv/--filters")),
 646                 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
 647                           N_("allow -s and -t to work with broken/corrupt objects")),
 648                 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
 649                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
 650                         N_("show info and content of objects fed from the standard input"),
 651                         PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
 652                         batch_option_callback },
 653                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 654                         N_("show info about objects fed from the standard input"),
 655                         PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
 656                         batch_option_callback },
 657                 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
 658                          N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 659                 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
 660                          N_("show all objects with --batch or --batch-check")),
 661                 OPT_BOOL(0, "unordered", &batch.unordered,
 662                          N_("do not order --batch-all-objects output")),
 663                 OPT_END()
 664         };
 665
 666         git_config(git_cat_file_config, NULL);
 667
 668         batch.buffer_output = -1;
 669         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 670
 671         if (opt) {
 672                 if (batch.enabled && (opt == 'c' || opt == 'w'))
 673                         batch.cmdmode = opt;
 674                 else if (argc == 1)
 675                         obj_name = argv[0];
 676                 else
 677                         usage_with_options(cat_file_usage, options);
 678         }
 679         if (!opt && !batch.enabled) {
 680                 if (argc == 2) {
 681                         exp_type = argv[0];
 682                         obj_name = argv[1];
 683                 } else
 684                         usage_with_options(cat_file_usage, options);
 685         }
 686         if (batch.enabled) {
 687                 if (batch.cmdmode != opt || argc)
 688                         usage_with_options(cat_file_usage, options);
 689                 if (batch.cmdmode && batch.all_objects)
 690                         die("--batch-all-objects cannot be combined with "
 691                             "--textconv nor with --filters");
 692         }
 693
 694         if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
 695                 usage_with_options(cat_file_usage, options);
 696         }
 697
 698         if (force_path && opt != 'c' && opt != 'w') {
 699                 error("--path=<path> needs --textconv or --filters");
 700                 usage_with_options(cat_file_usage, options);
 701         }
 702
 703         if (force_path && batch.enabled) {
 704                 error("--path=<path> incompatible with --batch");
 705                 usage_with_options(cat_file_usage, options);
 706         }
 707
 708         if (batch.buffer_output < 0)
 709                 batch.buffer_output = batch.all_objects;
 710
 711         if (batch.enabled)
 712                 return batch_objects(&batch);
 713
 714         if (unknown_type && opt != 't' && opt != 's')
 715                 die("git cat-file --allow-unknown-type: use with -s or -t");
 716         return cat_one_file(opt, exp_type, obj_name, unknown_type);
 717 }