builtin/cat-file.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "cache.h"
   7 #include "config.h"
   8 #include "builtin.h"
   9 #include "diff.h"
  10 #include "parse-options.h"
  11 #include "userdiff.h"
  12 #include "streaming.h"
  13 #include "tree-walk.h"
  14 #include "sha1-array.h"
  15 #include "packfile.h"
  16 #include "object-store.h"
  17
  18 struct batch_options {
  19         int enabled;
  20         int follow_symlinks;
  21         int print_contents;
  22         int buffer_output;
  23         int all_objects;
  24         int unordered;
  25         int cmdmode; /* may be 'w' or 'c' for --filters or --textconv */
  26         const char *format;
  27 };
  28
  29 static const char *force_path;
  30
  31 static int filter_object(const char *path, unsigned mode,
  32                          const struct object_id *oid,
  33                          char **buf, unsigned long *size)
  34 {
  35         enum object_type type;
  36
  37         *buf = read_object_file(oid, &type, size);
  38         if (!*buf)
  39                 return error(_("cannot read object %s '%s'"),
  40                              oid_to_hex(oid), path);
  41         if ((type == OBJ_BLOB) && S_ISREG(mode)) {
  42                 struct strbuf strbuf = STRBUF_INIT;
  43                 if (convert_to_working_tree(path, *buf, *size, &strbuf)) {
  44                         free(*buf);
  45                         *size = strbuf.len;
  46                         *buf = strbuf_detach(&strbuf, NULL);
  47                 }
  48         }
  49
  50         return 0;
  51 }
  52
  53 static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
  54                         int unknown_type)
  55 {
  56         struct object_id oid;
  57         enum object_type type;
  58         char *buf;
  59         unsigned long size;
  60         struct object_context obj_context;
  61         struct object_info oi = OBJECT_INFO_INIT;
  62         struct strbuf sb = STRBUF_INIT;
  63         unsigned flags = OBJECT_INFO_LOOKUP_REPLACE;
  64         const char *path = force_path;
  65
  66         if (unknown_type)
  67                 flags |= OBJECT_INFO_ALLOW_UNKNOWN_TYPE;
  68
  69         if (get_oid_with_context(obj_name, GET_OID_RECORD_PATH,
  70                                  &oid, &obj_context))
  71                 die("Not a valid object name %s", obj_name);
  72
  73         if (!path)
  74                 path = obj_context.path;
  75         if (obj_context.mode == S_IFINVALID)
  76                 obj_context.mode = 0100644;
  77
  78         buf = NULL;
  79         switch (opt) {
  80         case 't':
  81                 oi.type_name = &sb;
  82                 if (oid_object_info_extended(the_repository, &oid, &oi, flags) < 0)
  83                         die("git cat-file: could not get object info");
  84                 if (sb.len) {
  85                         printf("%s\n", sb.buf);
  86                         strbuf_release(&sb);
  87                         return 0;
  88                 }
  89                 break;
  90
  91         case 's':
  92                 oi.sizep = &size;
  93                 if (oid_object_info_extended(the_repository, &oid, &oi, flags) < 0)
  94                         die("git cat-file: could not get object info");
  95                 printf("%lu\n", size);
  96                 return 0;
  97
  98         case 'e':
  99                 return !has_object_file(&oid);
 100
 101         case 'w':
 102                 if (!path)
 103                         die("git cat-file --filters %s: <object> must be "
 104                             "<sha1:path>", obj_name);
 105
 106                 if (filter_object(path, obj_context.mode,
 107                                   &oid, &buf, &size))
 108                         return -1;
 109                 break;
 110
 111         case 'c':
 112                 if (!path)
 113                         die("git cat-file --textconv %s: <object> must be <sha1:path>",
 114                             obj_name);
 115
 116                 if (textconv_object(path, obj_context.mode, &oid, 1, &buf, &size))
 117                         break;
 118                 /* else fallthrough */
 119
 120         case 'p':
 121                 type = oid_object_info(the_repository, &oid, NULL);
 122                 if (type < 0)
 123                         die("Not a valid object name %s", obj_name);
 124
 125                 /* custom pretty-print here */
 126                 if (type == OBJ_TREE) {
 127                         const char *ls_args[3] = { NULL };
 128                         ls_args[0] =  "ls-tree";
 129                         ls_args[1] =  obj_name;
 130                         return cmd_ls_tree(2, ls_args, NULL);
 131                 }
 132
 133                 if (type == OBJ_BLOB)
 134                         return stream_blob_to_fd(1, &oid, NULL, 0);
 135                 buf = read_object_file(&oid, &type, &size);
 136                 if (!buf)
 137                         die("Cannot read object %s", obj_name);
 138
 139                 /* otherwise just spit out the data */
 140                 break;
 141
 142         case 0:
 143                 if (type_from_string(exp_type) == OBJ_BLOB) {
 144                         struct object_id blob_oid;
 145                         if (oid_object_info(the_repository, &oid, NULL) == OBJ_TAG) {
 146                                 char *buffer = read_object_file(&oid, &type,
 147                                                                 &size);
 148                                 const char *target;
 149                                 if (!skip_prefix(buffer, "object ", &target) ||
 150                                     get_oid_hex(target, &blob_oid))
 151                                         die("%s not a valid tag", oid_to_hex(&oid));
 152                                 free(buffer);
 153                         } else
 154                                 oidcpy(&blob_oid, &oid);
 155
 156                         if (oid_object_info(the_repository, &blob_oid, NULL) == OBJ_BLOB)
 157                                 return stream_blob_to_fd(1, &blob_oid, NULL, 0);
 158                         /*
 159                          * we attempted to dereference a tag to a blob
 160                          * and failed; there may be new dereference
 161                          * mechanisms this code is not aware of.
 162                          * fall-back to the usual case.
 163                          */
 164                 }
 165                 buf = read_object_with_reference(&oid, exp_type, &size, NULL);
 166                 break;
 167
 168         default:
 169                 die("git cat-file: unknown option: %s", exp_type);
 170         }
 171
 172         if (!buf)
 173                 die("git cat-file %s: bad file", obj_name);
 174
 175         write_or_die(1, buf, size);
 176         free(buf);
 177         free(obj_context.path);
 178         return 0;
 179 }
 180
 181 struct expand_data {
 182         struct object_id oid;
 183         enum object_type type;
 184         unsigned long size;
 185         off_t disk_size;
 186         const char *rest;
 187         struct object_id delta_base_oid;
 188
 189         /*
 190          * If mark_query is true, we do not expand anything, but rather
 191          * just mark the object_info with items we wish to query.
 192          */
 193         int mark_query;
 194
 195         /*
 196          * Whether to split the input on whitespace before feeding it to
 197          * get_sha1; this is decided during the mark_query phase based on
 198          * whether we have a %(rest) token in our format.
 199          */
 200         int split_on_whitespace;
 201
 202         /*
 203          * After a mark_query run, this object_info is set up to be
 204          * passed to sha1_object_info_extended. It will point to the data
 205          * elements above, so you can retrieve the response from there.
 206          */
 207         struct object_info info;
 208
 209         /*
 210          * This flag will be true if the requested batch format and options
 211          * don't require us to call sha1_object_info, which can then be
 212          * optimized out.
 213          */
 214         unsigned skip_object_info : 1;
 215 };
 216
 217 static int is_atom(const char *atom, const char *s, int slen)
 218 {
 219         int alen = strlen(atom);
 220         return alen == slen && !memcmp(atom, s, alen);
 221 }
 222
 223 static void expand_atom(struct strbuf *sb, const char *atom, int len,
 224                         void *vdata)
 225 {
 226         struct expand_data *data = vdata;
 227
 228         if (is_atom("objectname", atom, len)) {
 229                 if (!data->mark_query)
 230                         strbuf_addstr(sb, oid_to_hex(&data->oid));
 231         } else if (is_atom("objecttype", atom, len)) {
 232                 if (data->mark_query)
 233                         data->info.typep = &data->type;
 234                 else
 235                         strbuf_addstr(sb, type_name(data->type));
 236         } else if (is_atom("objectsize", atom, len)) {
 237                 if (data->mark_query)
 238                         data->info.sizep = &data->size;
 239                 else
 240                         strbuf_addf(sb, "%lu", data->size);
 241         } else if (is_atom("objectsize:disk", atom, len)) {
 242                 if (data->mark_query)
 243                         data->info.disk_sizep = &data->disk_size;
 244                 else
 245                         strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
 246         } else if (is_atom("rest", atom, len)) {
 247                 if (data->mark_query)
 248                         data->split_on_whitespace = 1;
 249                 else if (data->rest)
 250                         strbuf_addstr(sb, data->rest);
 251         } else if (is_atom("deltabase", atom, len)) {
 252                 if (data->mark_query)
 253                         data->info.delta_base_sha1 = data->delta_base_oid.hash;
 254                 else
 255                         strbuf_addstr(sb,
 256                                       oid_to_hex(&data->delta_base_oid));
 257         } else
 258                 die("unknown format element: %.*s", len, atom);
 259 }
 260
 261 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 262 {
 263         const char *end;
 264
 265         if (*start != '(')
 266                 return 0;
 267         end = strchr(start + 1, ')');
 268         if (!end)
 269                 die("format element '%s' does not end in ')'", start);
 270
 271         expand_atom(sb, start + 1, end - start - 1, data);
 272
 273         return end - start + 1;
 274 }
 275
 276 static void batch_write(struct batch_options *opt, const void *data, int len)
 277 {
 278         if (opt->buffer_output) {
 279                 if (fwrite(data, 1, len, stdout) != len)
 280                         die_errno("unable to write to stdout");
 281         } else
 282                 write_or_die(1, data, len);
 283 }
 284
 285 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
 286 {
 287         const struct object_id *oid = &data->oid;
 288
 289         assert(data->info.typep);
 290
 291         if (data->type == OBJ_BLOB) {
 292                 if (opt->buffer_output)
 293                         fflush(stdout);
 294                 if (opt->cmdmode) {
 295                         char *contents;
 296                         unsigned long size;
 297
 298                         if (!data->rest)
 299                                 die("missing path for '%s'", oid_to_hex(oid));
 300
 301                         if (opt->cmdmode == 'w') {
 302                                 if (filter_object(data->rest, 0100644, oid,
 303                                                   &contents, &size))
 304                                         die("could not convert '%s' %s",
 305                                             oid_to_hex(oid), data->rest);
 306                         } else if (opt->cmdmode == 'c') {
 307                                 enum object_type type;
 308                                 if (!textconv_object(data->rest, 0100644, oid,
 309                                                      1, &contents, &size))
 310                                         contents = read_object_file(oid,
 311                                                                     &type,
 312                                                                     &size);
 313                                 if (!contents)
 314                                         die("could not convert '%s' %s",
 315                                             oid_to_hex(oid), data->rest);
 316                         } else
 317                                 BUG("invalid cmdmode: %c", opt->cmdmode);
 318                         batch_write(opt, contents, size);
 319                         free(contents);
 320                 } else if (stream_blob_to_fd(1, oid, NULL, 0) < 0)
 321                         die("unable to stream %s to stdout", oid_to_hex(oid));
 322         }
 323         else {
 324                 enum object_type type;
 325                 unsigned long size;
 326                 void *contents;
 327
 328                 contents = read_object_file(oid, &type, &size);
 329                 if (!contents)
 330                         die("object %s disappeared", oid_to_hex(oid));
 331                 if (type != data->type)
 332                         die("object %s changed type!?", oid_to_hex(oid));
 333                 if (data->info.sizep && size != data->size)
 334                         die("object %s changed size!?", oid_to_hex(oid));
 335
 336                 batch_write(opt, contents, size);
 337                 free(contents);
 338         }
 339 }
 340
 341 static void batch_object_write(const char *obj_name, struct batch_options *opt,
 342                                struct expand_data *data)
 343 {
 344         struct strbuf buf = STRBUF_INIT;
 345
 346         if (!data->skip_object_info &&
 347             oid_object_info_extended(the_repository, &data->oid, &data->info,
 348                                      OBJECT_INFO_LOOKUP_REPLACE) < 0) {
 349                 printf("%s missing\n",
 350                        obj_name ? obj_name : oid_to_hex(&data->oid));
 351                 fflush(stdout);
 352                 return;
 353         }
 354
 355         strbuf_expand(&buf, opt->format, expand_format, data);
 356         strbuf_addch(&buf, '\n');
 357         batch_write(opt, buf.buf, buf.len);
 358         strbuf_release(&buf);
 359
 360         if (opt->print_contents) {
 361                 print_object_or_die(opt, data);
 362                 batch_write(opt, "\n", 1);
 363         }
 364 }
 365
 366 static void batch_one_object(const char *obj_name, struct batch_options *opt,
 367                              struct expand_data *data)
 368 {
 369         struct object_context ctx;
 370         int flags = opt->follow_symlinks ? GET_OID_FOLLOW_SYMLINKS : 0;
 371         enum follow_symlinks_result result;
 372
 373         result = get_oid_with_context(obj_name, flags, &data->oid, &ctx);
 374         if (result != FOUND) {
 375                 switch (result) {
 376                 case MISSING_OBJECT:
 377                         printf("%s missing\n", obj_name);
 378                         break;
 379                 case DANGLING_SYMLINK:
 380                         printf("dangling %"PRIuMAX"\n%s\n",
 381                                (uintmax_t)strlen(obj_name), obj_name);
 382                         break;
 383                 case SYMLINK_LOOP:
 384                         printf("loop %"PRIuMAX"\n%s\n",
 385                                (uintmax_t)strlen(obj_name), obj_name);
 386                         break;
 387                 case NOT_DIR:
 388                         printf("notdir %"PRIuMAX"\n%s\n",
 389                                (uintmax_t)strlen(obj_name), obj_name);
 390                         break;
 391                 default:
 392                         BUG("unknown get_sha1_with_context result %d\n",
 393                                result);
 394                         break;
 395                 }
 396                 fflush(stdout);
 397                 return;
 398         }
 399
 400         if (ctx.mode == 0) {
 401                 printf("symlink %"PRIuMAX"\n%s\n",
 402                        (uintmax_t)ctx.symlink_path.len,
 403                        ctx.symlink_path.buf);
 404                 fflush(stdout);
 405                 return;
 406         }
 407
 408         batch_object_write(obj_name, opt, data);
 409 }
 410
 411 struct object_cb_data {
 412         struct batch_options *opt;
 413         struct expand_data *expand;
 414         struct oidset *seen;
 415 };
 416
 417 static int batch_object_cb(const struct object_id *oid, void *vdata)
 418 {
 419         struct object_cb_data *data = vdata;
 420         oidcpy(&data->expand->oid, oid);
 421         batch_object_write(NULL, data->opt, data->expand);
 422         return 0;
 423 }
 424
 425 static int collect_loose_object(const struct object_id *oid,
 426                                 const char *path,
 427                                 void *data)
 428 {
 429         oid_array_append(data, oid);
 430         return 0;
 431 }
 432
 433 static int collect_packed_object(const struct object_id *oid,
 434                                  struct packed_git *pack,
 435                                  uint32_t pos,
 436                                  void *data)
 437 {
 438         oid_array_append(data, oid);
 439         return 0;
 440 }
 441
 442 static int batch_unordered_object(const struct object_id *oid, void *vdata)
 443 {
 444         struct object_cb_data *data = vdata;
 445
 446         if (oidset_insert(data->seen, oid))
 447                 return 0;
 448
 449         return batch_object_cb(oid, data);
 450 }
 451
 452 static int batch_unordered_loose(const struct object_id *oid,
 453                                  const char *path,
 454                                  void *data)
 455 {
 456         return batch_unordered_object(oid, data);
 457 }
 458
 459 static int batch_unordered_packed(const struct object_id *oid,
 460                                   struct packed_git *pack,
 461                                   uint32_t pos,
 462                                   void *data)
 463 {
 464         return batch_unordered_object(oid, data);
 465 }
 466
 467 static int batch_objects(struct batch_options *opt)
 468 {
 469         struct strbuf buf = STRBUF_INIT;
 470         struct expand_data data;
 471         int save_warning;
 472         int retval = 0;
 473
 474         if (!opt->format)
 475                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
 476
 477         /*
 478          * Expand once with our special mark_query flag, which will prime the
 479          * object_info to be handed to sha1_object_info_extended for each
 480          * object.
 481          */
 482         memset(&data, 0, sizeof(data));
 483         data.mark_query = 1;
 484         strbuf_expand(&buf, opt->format, expand_format, &data);
 485         data.mark_query = 0;
 486         if (opt->cmdmode)
 487                 data.split_on_whitespace = 1;
 488
 489         if (opt->all_objects) {
 490                 struct object_info empty = OBJECT_INFO_INIT;
 491                 if (!memcmp(&data.info, &empty, sizeof(empty)))
 492                         data.skip_object_info = 1;
 493         }
 494
 495         /*
 496          * If we are printing out the object, then always fill in the type,
 497          * since we will want to decide whether or not to stream.
 498          */
 499         if (opt->print_contents)
 500                 data.info.typep = &data.type;
 501
 502         if (opt->all_objects) {
 503                 struct object_cb_data cb;
 504
 505                 if (repository_format_partial_clone)
 506                         warning("This repository has extensions.partialClone set. Some objects may not be loaded.");
 507
 508                 cb.opt = opt;
 509                 cb.expand = &data;
 510
 511                 if (opt->unordered) {
 512                         struct oidset seen = OIDSET_INIT;
 513
 514                         cb.seen = &seen;
 515
 516                         for_each_loose_object(batch_unordered_loose, &cb, 0);
 517                         for_each_packed_object(batch_unordered_packed, &cb,
 518                                                FOR_EACH_OBJECT_PACK_ORDER);
 519
 520                         oidset_clear(&seen);
 521                 } else {
 522                         struct oid_array sa = OID_ARRAY_INIT;
 523
 524                         for_each_loose_object(collect_loose_object, &sa, 0);
 525                         for_each_packed_object(collect_packed_object, &sa, 0);
 526
 527                         oid_array_for_each_unique(&sa, batch_object_cb, &cb);
 528
 529                         oid_array_clear(&sa);
 530                 }
 531
 532                 return 0;
 533         }
 534
 535         /*
 536          * We are going to call get_sha1 on a potentially very large number of
 537          * objects. In most large cases, these will be actual object sha1s. The
 538          * cost to double-check that each one is not also a ref (just so we can
 539          * warn) ends up dwarfing the actual cost of the object lookups
 540          * themselves. We can work around it by just turning off the warning.
 541          */
 542         save_warning = warn_on_object_refname_ambiguity;
 543         warn_on_object_refname_ambiguity = 0;
 544
 545         while (strbuf_getline(&buf, stdin) != EOF) {
 546                 if (data.split_on_whitespace) {
 547                         /*
 548                          * Split at first whitespace, tying off the beginning
 549                          * of the string and saving the remainder (or NULL) in
 550                          * data.rest.
 551                          */
 552                         char *p = strpbrk(buf.buf, " \t");
 553                         if (p) {
 554                                 while (*p && strchr(" \t", *p))
 555                                         *p++ = '\0';
 556                         }
 557                         data.rest = p;
 558                 }
 559
 560                 batch_one_object(buf.buf, opt, &data);
 561         }
 562
 563         strbuf_release(&buf);
 564         warn_on_object_refname_ambiguity = save_warning;
 565         return retval;
 566 }
 567
 568 static const char * const cat_file_usage[] = {
 569         N_("git cat-file (-t [--allow-unknown-type] | -s [--allow-unknown-type] | -e | -p | <type> | --textconv | --filters) [--path=<path>] <object>"),
 570         N_("git cat-file (--batch | --batch-check) [--follow-symlinks] [--textconv | --filters]"),
 571         NULL
 572 };
 573
 574 static int git_cat_file_config(const char *var, const char *value, void *cb)
 575 {
 576         if (userdiff_config(var, value) < 0)
 577                 return -1;
 578
 579         return git_default_config(var, value, cb);
 580 }
 581
 582 static int batch_option_callback(const struct option *opt,
 583                                  const char *arg,
 584                                  int unset)
 585 {
 586         struct batch_options *bo = opt->value;
 587
 588         if (bo->enabled) {
 589                 return 1;
 590         }
 591
 592         bo->enabled = 1;
 593         bo->print_contents = !strcmp(opt->long_name, "batch");
 594         bo->format = arg;
 595
 596         return 0;
 597 }
 598
 599 int cmd_cat_file(int argc, const char **argv, const char *prefix)
 600 {
 601         int opt = 0;
 602         const char *exp_type = NULL, *obj_name = NULL;
 603         struct batch_options batch = {0};
 604         int unknown_type = 0;
 605
 606         const struct option options[] = {
 607                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 608                 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
 609                 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
 610                 OPT_CMDMODE('e', NULL, &opt,
 611                             N_("exit with zero when there's no error"), 'e'),
 612                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 613                 OPT_CMDMODE(0, "textconv", &opt,
 614                             N_("for blob objects, run textconv on object's content"), 'c'),
 615                 OPT_CMDMODE(0, "filters", &opt,
 616                             N_("for blob objects, run filters on object's content"), 'w'),
 617                 OPT_STRING(0, "path", &force_path, N_("blob"),
 618                            N_("use a specific path for --textconv/--filters")),
 619                 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
 620                           N_("allow -s and -t to work with broken/corrupt objects")),
 621                 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
 622                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
 623                         N_("show info and content of objects fed from the standard input"),
 624                         PARSE_OPT_OPTARG, batch_option_callback },
 625                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 626                         N_("show info about objects fed from the standard input"),
 627                         PARSE_OPT_OPTARG, batch_option_callback },
 628                 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
 629                          N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 630                 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
 631                          N_("show all objects with --batch or --batch-check")),
 632                 OPT_BOOL(0, "unordered", &batch.unordered,
 633                          N_("do not order --batch-all-objects output")),
 634                 OPT_END()
 635         };
 636
 637         git_config(git_cat_file_config, NULL);
 638
 639         batch.buffer_output = -1;
 640         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 641
 642         if (opt) {
 643                 if (batch.enabled && (opt == 'c' || opt == 'w'))
 644                         batch.cmdmode = opt;
 645                 else if (argc == 1)
 646                         obj_name = argv[0];
 647                 else
 648                         usage_with_options(cat_file_usage, options);
 649         }
 650         if (!opt && !batch.enabled) {
 651                 if (argc == 2) {
 652                         exp_type = argv[0];
 653                         obj_name = argv[1];
 654                 } else
 655                         usage_with_options(cat_file_usage, options);
 656         }
 657         if (batch.enabled) {
 658                 if (batch.cmdmode != opt || argc)
 659                         usage_with_options(cat_file_usage, options);
 660                 if (batch.cmdmode && batch.all_objects)
 661                         die("--batch-all-objects cannot be combined with "
 662                             "--textconv nor with --filters");
 663         }
 664
 665         if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
 666                 usage_with_options(cat_file_usage, options);
 667         }
 668
 669         if (force_path && opt != 'c' && opt != 'w') {
 670                 error("--path=<path> needs --textconv or --filters");
 671                 usage_with_options(cat_file_usage, options);
 672         }
 673
 674         if (force_path && batch.enabled) {
 675                 error("--path=<path> incompatible with --batch");
 676                 usage_with_options(cat_file_usage, options);
 677         }
 678
 679         if (batch.buffer_output < 0)
 680                 batch.buffer_output = batch.all_objects;
 681
 682         if (batch.enabled)
 683                 return batch_objects(&batch);
 684
 685         if (unknown_type && opt != 't' && opt != 's')
 686                 die("git cat-file --allow-unknown-type: use with -s or -t");
 687         return cat_one_file(opt, exp_type, obj_name, unknown_type);
 688 }