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