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(&oid, exp_type, &size, NULL);
 176                 break;
 177
 178         default:
 179                 die("git cat-file: unknown option: %s", exp_type);
 180         }
 181
 182         if (!buf)
 183                 die("git cat-file %s: bad file", obj_name);
 184
 185         write_or_die(1, buf, size);
 186         free(buf);
 187         free(obj_context.path);
 188         return 0;
 189 }
 190
 191 struct expand_data {
 192         struct object_id oid;
 193         enum object_type type;
 194         unsigned long size;
 195         off_t disk_size;
 196         const char *rest;
 197         struct object_id delta_base_oid;
 198
 199         /*
 200          * If mark_query is true, we do not expand anything, but rather
 201          * just mark the object_info with items we wish to query.
 202          */
 203         int mark_query;
 204
 205         /*
 206          * Whether to split the input on whitespace before feeding it to
 207          * get_sha1; this is decided during the mark_query phase based on
 208          * whether we have a %(rest) token in our format.
 209          */
 210         int split_on_whitespace;
 211
 212         /*
 213          * After a mark_query run, this object_info is set up to be
 214          * passed to oid_object_info_extended. It will point to the data
 215          * elements above, so you can retrieve the response from there.
 216          */
 217         struct object_info info;
 218
 219         /*
 220          * This flag will be true if the requested batch format and options
 221          * don't require us to call oid_object_info, which can then be
 222          * optimized out.
 223          */
 224         unsigned skip_object_info : 1;
 225 };
 226
 227 static int is_atom(const char *atom, const char *s, int slen)
 228 {
 229         int alen = strlen(atom);
 230         return alen == slen && !memcmp(atom, s, alen);
 231 }
 232
 233 static void expand_atom(struct strbuf *sb, const char *atom, int len,
 234                         void *vdata)
 235 {
 236         struct expand_data *data = vdata;
 237
 238         if (is_atom("objectname", atom, len)) {
 239                 if (!data->mark_query)
 240                         strbuf_addstr(sb, oid_to_hex(&data->oid));
 241         } else if (is_atom("objecttype", atom, len)) {
 242                 if (data->mark_query)
 243                         data->info.typep = &data->type;
 244                 else
 245                         strbuf_addstr(sb, type_name(data->type));
 246         } else if (is_atom("objectsize", atom, len)) {
 247                 if (data->mark_query)
 248                         data->info.sizep = &data->size;
 249                 else
 250                         strbuf_addf(sb, "%"PRIuMAX , (uintmax_t)data->size);
 251         } else if (is_atom("objectsize:disk", atom, len)) {
 252                 if (data->mark_query)
 253                         data->info.disk_sizep = &data->disk_size;
 254                 else
 255                         strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
 256         } else if (is_atom("rest", atom, len)) {
 257                 if (data->mark_query)
 258                         data->split_on_whitespace = 1;
 259                 else if (data->rest)
 260                         strbuf_addstr(sb, data->rest);
 261         } else if (is_atom("deltabase", atom, len)) {
 262                 if (data->mark_query)
 263                         data->info.delta_base_sha1 = data->delta_base_oid.hash;
 264                 else
 265                         strbuf_addstr(sb,
 266                                       oid_to_hex(&data->delta_base_oid));
 267         } else
 268                 die("unknown format element: %.*s", len, atom);
 269 }
 270
 271 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 272 {
 273         const char *end;
 274
 275         if (*start != '(')
 276                 return 0;
 277         end = strchr(start + 1, ')');
 278         if (!end)
 279                 die("format element '%s' does not end in ')'", start);
 280
 281         expand_atom(sb, start + 1, end - start - 1, data);
 282
 283         return end - start + 1;
 284 }
 285
 286 static void batch_write(struct batch_options *opt, const void *data, int len)
 287 {
 288         if (opt->buffer_output) {
 289                 if (fwrite(data, 1, len, stdout) != len)
 290                         die_errno("unable to write to stdout");
 291         } else
 292                 write_or_die(1, data, len);
 293 }
 294
 295 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
 296 {
 297         const struct object_id *oid = &data->oid;
 298
 299         assert(data->info.typep);
 300
 301         if (data->type == OBJ_BLOB) {
 302                 if (opt->buffer_output)
 303                         fflush(stdout);
 304                 if (opt->cmdmode) {
 305                         char *contents;
 306                         unsigned long size;
 307
 308                         if (!data->rest)
 309                                 die("missing path for '%s'", oid_to_hex(oid));
 310
 311                         if (opt->cmdmode == 'w') {
 312                                 if (filter_object(data->rest, 0100644, oid,
 313                                                   &contents, &size))
 314                                         die("could not convert '%s' %s",
 315                                             oid_to_hex(oid), data->rest);
 316                         } else if (opt->cmdmode == 'c') {
 317                                 enum object_type type;
 318                                 if (!textconv_object(the_repository,
 319                                                      data->rest, 0100644, oid,
 320                                                      1, &contents, &size))
 321                                         contents = read_object_file(oid,
 322                                                                     &type,
 323                                                                     &size);
 324                                 if (!contents)
 325                                         die("could not convert '%s' %s",
 326                                             oid_to_hex(oid), data->rest);
 327                         } else
 328                                 BUG("invalid cmdmode: %c", opt->cmdmode);
 329                         batch_write(opt, contents, size);
 330                         free(contents);
 331                 } else {
 332                         stream_blob(oid);
 333                 }
 334         }
 335         else {
 336                 enum object_type type;
 337                 unsigned long size;
 338                 void *contents;
 339
 340                 contents = read_object_file(oid, &type, &size);
 341                 if (!contents)
 342                         die("object %s disappeared", oid_to_hex(oid));
 343                 if (type != data->type)
 344                         die("object %s changed type!?", oid_to_hex(oid));
 345                 if (data->info.sizep && size != data->size)
 346                         die("object %s changed size!?", oid_to_hex(oid));
 347
 348                 batch_write(opt, contents, size);
 349                 free(contents);
 350         }
 351 }
 352
 353 static void batch_object_write(const char *obj_name,
 354                                struct strbuf *scratch,
 355                                struct batch_options *opt,
 356                                struct expand_data *data)
 357 {
 358         if (!data->skip_object_info &&
 359             oid_object_info_extended(the_repository, &data->oid, &data->info,
 360                                      OBJECT_INFO_LOOKUP_REPLACE) < 0) {
 361                 printf("%s missing\n",
 362                        obj_name ? obj_name : oid_to_hex(&data->oid));
 363                 fflush(stdout);
 364                 return;
 365         }
 366
 367         strbuf_reset(scratch);
 368         strbuf_expand(scratch, opt->format, expand_format, data);
 369         strbuf_addch(scratch, '\n');
 370         batch_write(opt, scratch->buf, scratch->len);
 371
 372         if (opt->print_contents) {
 373                 print_object_or_die(opt, data);
 374                 batch_write(opt, "\n", 1);
 375         }
 376 }
 377
 378 static void batch_one_object(const char *obj_name,
 379                              struct strbuf *scratch,
 380                              struct batch_options *opt,
 381                              struct expand_data *data)
 382 {
 383         struct object_context ctx;
 384         int flags = opt->follow_symlinks ? GET_OID_FOLLOW_SYMLINKS : 0;
 385         enum get_oid_result result;
 386
 387         result = get_oid_with_context(the_repository, obj_name,
 388                                       flags, &data->oid, &ctx);
 389         if (result != FOUND) {
 390                 switch (result) {
 391                 case MISSING_OBJECT:
 392                         printf("%s missing\n", obj_name);
 393                         break;
 394                 case SHORT_NAME_AMBIGUOUS:
 395                         printf("%s ambiguous\n", obj_name);
 396                         break;
 397                 case DANGLING_SYMLINK:
 398                         printf("dangling %"PRIuMAX"\n%s\n",
 399                                (uintmax_t)strlen(obj_name), obj_name);
 400                         break;
 401                 case SYMLINK_LOOP:
 402                         printf("loop %"PRIuMAX"\n%s\n",
 403                                (uintmax_t)strlen(obj_name), obj_name);
 404                         break;
 405                 case NOT_DIR:
 406                         printf("notdir %"PRIuMAX"\n%s\n",
 407                                (uintmax_t)strlen(obj_name), obj_name);
 408                         break;
 409                 default:
 410                         BUG("unknown get_sha1_with_context result %d\n",
 411                                result);
 412                         break;
 413                 }
 414                 fflush(stdout);
 415                 return;
 416         }
 417
 418         if (ctx.mode == 0) {
 419                 printf("symlink %"PRIuMAX"\n%s\n",
 420                        (uintmax_t)ctx.symlink_path.len,
 421                        ctx.symlink_path.buf);
 422                 fflush(stdout);
 423                 return;
 424         }
 425
 426         batch_object_write(obj_name, scratch, opt, data);
 427 }
 428
 429 struct object_cb_data {
 430         struct batch_options *opt;
 431         struct expand_data *expand;
 432         struct oidset *seen;
 433         struct strbuf *scratch;
 434 };
 435
 436 static int batch_object_cb(const struct object_id *oid, void *vdata)
 437 {
 438         struct object_cb_data *data = vdata;
 439         oidcpy(&data->expand->oid, oid);
 440         batch_object_write(NULL, data->scratch, data->opt, data->expand);
 441         return 0;
 442 }
 443
 444 static int collect_loose_object(const struct object_id *oid,
 445                                 const char *path,
 446                                 void *data)
 447 {
 448         oid_array_append(data, oid);
 449         return 0;
 450 }
 451
 452 static int collect_packed_object(const struct object_id *oid,
 453                                  struct packed_git *pack,
 454                                  uint32_t pos,
 455                                  void *data)
 456 {
 457         oid_array_append(data, oid);
 458         return 0;
 459 }
 460
 461 static int batch_unordered_object(const struct object_id *oid, void *vdata)
 462 {
 463         struct object_cb_data *data = vdata;
 464
 465         if (oidset_insert(data->seen, oid))
 466                 return 0;
 467
 468         return batch_object_cb(oid, data);
 469 }
 470
 471 static int batch_unordered_loose(const struct object_id *oid,
 472                                  const char *path,
 473                                  void *data)
 474 {
 475         return batch_unordered_object(oid, data);
 476 }
 477
 478 static int batch_unordered_packed(const struct object_id *oid,
 479                                   struct packed_git *pack,
 480                                   uint32_t pos,
 481                                   void *data)
 482 {
 483         return batch_unordered_object(oid, data);
 484 }
 485
 486 static int batch_objects(struct batch_options *opt)
 487 {
 488         struct strbuf input = STRBUF_INIT;
 489         struct strbuf output = STRBUF_INIT;
 490         struct expand_data data;
 491         int save_warning;
 492         int retval = 0;
 493
 494         if (!opt->format)
 495                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
 496
 497         /*
 498          * Expand once with our special mark_query flag, which will prime the
 499          * object_info to be handed to oid_object_info_extended for each
 500          * object.
 501          */
 502         memset(&data, 0, sizeof(data));
 503         data.mark_query = 1;
 504         strbuf_expand(&output, opt->format, expand_format, &data);
 505         data.mark_query = 0;
 506         strbuf_release(&output);
 507         if (opt->cmdmode)
 508                 data.split_on_whitespace = 1;
 509
 510         if (opt->all_objects) {
 511                 struct object_info empty = OBJECT_INFO_INIT;
 512                 if (!memcmp(&data.info, &empty, sizeof(empty)))
 513                         data.skip_object_info = 1;
 514         }
 515
 516         /*
 517          * If we are printing out the object, then always fill in the type,
 518          * since we will want to decide whether or not to stream.
 519          */
 520         if (opt->print_contents)
 521                 data.info.typep = &data.type;
 522
 523         if (opt->all_objects) {
 524                 struct object_cb_data cb;
 525
 526                 if (repository_format_partial_clone)
 527                         warning("This repository has extensions.partialClone set. Some objects may not be loaded.");
 528
 529                 cb.opt = opt;
 530                 cb.expand = &data;
 531                 cb.scratch = &output;
 532
 533                 if (opt->unordered) {
 534                         struct oidset seen = OIDSET_INIT;
 535
 536                         cb.seen = &seen;
 537
 538                         for_each_loose_object(batch_unordered_loose, &cb, 0);
 539                         for_each_packed_object(batch_unordered_packed, &cb,
 540                                                FOR_EACH_OBJECT_PACK_ORDER);
 541
 542                         oidset_clear(&seen);
 543                 } else {
 544                         struct oid_array sa = OID_ARRAY_INIT;
 545
 546                         for_each_loose_object(collect_loose_object, &sa, 0);
 547                         for_each_packed_object(collect_packed_object, &sa, 0);
 548
 549                         oid_array_for_each_unique(&sa, batch_object_cb, &cb);
 550
 551                         oid_array_clear(&sa);
 552                 }
 553
 554                 strbuf_release(&output);
 555                 return 0;
 556         }
 557
 558         /*
 559          * We are going to call get_sha1 on a potentially very large number of
 560          * objects. In most large cases, these will be actual object sha1s. The
 561          * cost to double-check that each one is not also a ref (just so we can
 562          * warn) ends up dwarfing the actual cost of the object lookups
 563          * themselves. We can work around it by just turning off the warning.
 564          */
 565         save_warning = warn_on_object_refname_ambiguity;
 566         warn_on_object_refname_ambiguity = 0;
 567
 568         while (strbuf_getline(&input, stdin) != EOF) {
 569                 if (data.split_on_whitespace) {
 570                         /*
 571                          * Split at first whitespace, tying off the beginning
 572                          * of the string and saving the remainder (or NULL) in
 573                          * data.rest.
 574                          */
 575                         char *p = strpbrk(input.buf, " \t");
 576                         if (p) {
 577                                 while (*p && strchr(" \t", *p))
 578                                         *p++ = '\0';
 579                         }
 580                         data.rest = p;
 581                 }
 582
 583                 batch_one_object(input.buf, &output, opt, &data);
 584         }
 585
 586         strbuf_release(&input);
 587         strbuf_release(&output);
 588         warn_on_object_refname_ambiguity = save_warning;
 589         return retval;
 590 }
 591
 592 static const char * const cat_file_usage[] = {
 593         N_("git cat-file (-t [--allow-unknown-type] | -s [--allow-unknown-type] | -e | -p | <type> | --textconv | --filters) [--path=<path>] <object>"),
 594         N_("git cat-file (--batch | --batch-check) [--follow-symlinks] [--textconv | --filters]"),
 595         NULL
 596 };
 597
 598 static int git_cat_file_config(const char *var, const char *value, void *cb)
 599 {
 600         if (userdiff_config(var, value) < 0)
 601                 return -1;
 602
 603         return git_default_config(var, value, cb);
 604 }
 605
 606 static int batch_option_callback(const struct option *opt,
 607                                  const char *arg,
 608                                  int unset)
 609 {
 610         struct batch_options *bo = opt->value;
 611
 612         BUG_ON_OPT_NEG(unset);
 613
 614         if (bo->enabled) {
 615                 return error(_("only one batch option may be specified"));
 616         }
 617
 618         bo->enabled = 1;
 619         bo->print_contents = !strcmp(opt->long_name, "batch");
 620         bo->format = arg;
 621
 622         return 0;
 623 }
 624
 625 int cmd_cat_file(int argc, const char **argv, const char *prefix)
 626 {
 627         int opt = 0;
 628         const char *exp_type = NULL, *obj_name = NULL;
 629         struct batch_options batch = {0};
 630         int unknown_type = 0;
 631
 632         const struct option options[] = {
 633                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 634                 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
 635                 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
 636                 OPT_CMDMODE('e', NULL, &opt,
 637                             N_("exit with zero when there's no error"), 'e'),
 638                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 639                 OPT_CMDMODE(0, "textconv", &opt,
 640                             N_("for blob objects, run textconv on object's content"), 'c'),
 641                 OPT_CMDMODE(0, "filters", &opt,
 642                             N_("for blob objects, run filters on object's content"), 'w'),
 643                 OPT_STRING(0, "path", &force_path, N_("blob"),
 644                            N_("use a specific path for --textconv/--filters")),
 645                 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
 646                           N_("allow -s and -t to work with broken/corrupt objects")),
 647                 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
 648                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
 649                         N_("show info and content of objects fed from the standard input"),
 650                         PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
 651                         batch_option_callback },
 652                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 653                         N_("show info about objects fed from the standard input"),
 654                         PARSE_OPT_OPTARG | PARSE_OPT_NONEG,
 655                         batch_option_callback },
 656                 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
 657                          N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 658                 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
 659                          N_("show all objects with --batch or --batch-check")),
 660                 OPT_BOOL(0, "unordered", &batch.unordered,
 661                          N_("do not order --batch-all-objects output")),
 662                 OPT_END()
 663         };
 664
 665         git_config(git_cat_file_config, NULL);
 666
 667         batch.buffer_output = -1;
 668         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 669
 670         if (opt) {
 671                 if (batch.enabled && (opt == 'c' || opt == 'w'))
 672                         batch.cmdmode = opt;
 673                 else if (argc == 1)
 674                         obj_name = argv[0];
 675                 else
 676                         usage_with_options(cat_file_usage, options);
 677         }
 678         if (!opt && !batch.enabled) {
 679                 if (argc == 2) {
 680                         exp_type = argv[0];
 681                         obj_name = argv[1];
 682                 } else
 683                         usage_with_options(cat_file_usage, options);
 684         }
 685         if (batch.enabled) {
 686                 if (batch.cmdmode != opt || argc)
 687                         usage_with_options(cat_file_usage, options);
 688                 if (batch.cmdmode && batch.all_objects)
 689                         die("--batch-all-objects cannot be combined with "
 690                             "--textconv nor with --filters");
 691         }
 692
 693         if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
 694                 usage_with_options(cat_file_usage, options);
 695         }
 696
 697         if (force_path && opt != 'c' && opt != 'w') {
 698                 error("--path=<path> needs --textconv or --filters");
 699                 usage_with_options(cat_file_usage, options);
 700         }
 701
 702         if (force_path && batch.enabled) {
 703                 error("--path=<path> incompatible with --batch");
 704                 usage_with_options(cat_file_usage, options);
 705         }
 706
 707         if (batch.buffer_output < 0)
 708                 batch.buffer_output = batch.all_objects;
 709
 710         if (batch.enabled)
 711                 return batch_objects(&batch);
 712
 713         if (unknown_type && opt != 't' && opt != 's')
 714                 die("git cat-file --allow-unknown-type: use with -s or -t");
 715         return cat_one_file(opt, exp_type, obj_name, unknown_type);
 716 }