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_sha1_file(oid->hash, &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.typename = &sb;
  80                 if (sha1_object_info_extended(oid.hash, &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 (sha1_object_info_extended(oid.hash, &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 = sha1_object_info(oid.hash, 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_sha1_file(oid.hash, &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 (sha1_object_info(oid.hash, NULL) == OBJ_TAG) {
 144                                 char *buffer = read_sha1_file(oid.hash, &type, &size);
 145                                 const char *target;
 146                                 if (!skip_prefix(buffer, "object ", &target) ||
 147                                     get_oid_hex(target, &blob_oid))
 148                                         die("%s not a valid tag", oid_to_hex(&oid));
 149                                 free(buffer);
 150                         } else
 151                                 oidcpy(&blob_oid, &oid);
 152
 153                         if (sha1_object_info(blob_oid.hash, NULL) == OBJ_BLOB)
 154                                 return stream_blob_to_fd(1, &blob_oid, NULL, 0);
 155                         /*
 156                          * we attempted to dereference a tag to a blob
 157                          * and failed; there may be new dereference
 158                          * mechanisms this code is not aware of.
 159                          * fall-back to the usual case.
 160                          */
 161                 }
 162                 buf = read_object_with_reference(oid.hash, exp_type, &size, NULL);
 163                 break;
 164
 165         default:
 166                 die("git cat-file: unknown option: %s", exp_type);
 167         }
 168
 169         if (!buf)
 170                 die("git cat-file %s: bad file", obj_name);
 171
 172         write_or_die(1, buf, size);
 173         free(buf);
 174         free(obj_context.path);
 175         return 0;
 176 }
 177
 178 struct expand_data {
 179         struct object_id oid;
 180         enum object_type type;
 181         unsigned long size;
 182         off_t disk_size;
 183         const char *rest;
 184         struct object_id delta_base_oid;
 185
 186         /*
 187          * If mark_query is true, we do not expand anything, but rather
 188          * just mark the object_info with items we wish to query.
 189          */
 190         int mark_query;
 191
 192         /*
 193          * Whether to split the input on whitespace before feeding it to
 194          * get_sha1; this is decided during the mark_query phase based on
 195          * whether we have a %(rest) token in our format.
 196          */
 197         int split_on_whitespace;
 198
 199         /*
 200          * After a mark_query run, this object_info is set up to be
 201          * passed to sha1_object_info_extended. It will point to the data
 202          * elements above, so you can retrieve the response from there.
 203          */
 204         struct object_info info;
 205
 206         /*
 207          * This flag will be true if the requested batch format and options
 208          * don't require us to call sha1_object_info, which can then be
 209          * optimized out.
 210          */
 211         unsigned skip_object_info : 1;
 212 };
 213
 214 static int is_atom(const char *atom, const char *s, int slen)
 215 {
 216         int alen = strlen(atom);
 217         return alen == slen && !memcmp(atom, s, alen);
 218 }
 219
 220 static void expand_atom(struct strbuf *sb, const char *atom, int len,
 221                         void *vdata)
 222 {
 223         struct expand_data *data = vdata;
 224
 225         if (is_atom("objectname", atom, len)) {
 226                 if (!data->mark_query)
 227                         strbuf_addstr(sb, oid_to_hex(&data->oid));
 228         } else if (is_atom("objecttype", atom, len)) {
 229                 if (data->mark_query)
 230                         data->info.typep = &data->type;
 231                 else
 232                         strbuf_addstr(sb, typename(data->type));
 233         } else if (is_atom("objectsize", atom, len)) {
 234                 if (data->mark_query)
 235                         data->info.sizep = &data->size;
 236                 else
 237                         strbuf_addf(sb, "%lu", data->size);
 238         } else if (is_atom("objectsize:disk", atom, len)) {
 239                 if (data->mark_query)
 240                         data->info.disk_sizep = &data->disk_size;
 241                 else
 242                         strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
 243         } else if (is_atom("rest", atom, len)) {
 244                 if (data->mark_query)
 245                         data->split_on_whitespace = 1;
 246                 else if (data->rest)
 247                         strbuf_addstr(sb, data->rest);
 248         } else if (is_atom("deltabase", atom, len)) {
 249                 if (data->mark_query)
 250                         data->info.delta_base_sha1 = data->delta_base_oid.hash;
 251                 else
 252                         strbuf_addstr(sb,
 253                                       oid_to_hex(&data->delta_base_oid));
 254         } else
 255                 die("unknown format element: %.*s", len, atom);
 256 }
 257
 258 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 259 {
 260         const char *end;
 261
 262         if (*start != '(')
 263                 return 0;
 264         end = strchr(start + 1, ')');
 265         if (!end)
 266                 die("format element '%s' does not end in ')'", start);
 267
 268         expand_atom(sb, start + 1, end - start - 1, data);
 269
 270         return end - start + 1;
 271 }
 272
 273 static void batch_write(struct batch_options *opt, const void *data, int len)
 274 {
 275         if (opt->buffer_output) {
 276                 if (fwrite(data, 1, len, stdout) != len)
 277                         die_errno("unable to write to stdout");
 278         } else
 279                 write_or_die(1, data, len);
 280 }
 281
 282 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
 283 {
 284         const struct object_id *oid = &data->oid;
 285
 286         assert(data->info.typep);
 287
 288         if (data->type == OBJ_BLOB) {
 289                 if (opt->buffer_output)
 290                         fflush(stdout);
 291                 if (opt->cmdmode) {
 292                         char *contents;
 293                         unsigned long size;
 294
 295                         if (!data->rest)
 296                                 die("missing path for '%s'", oid_to_hex(oid));
 297
 298                         if (opt->cmdmode == 'w') {
 299                                 if (filter_object(data->rest, 0100644, oid,
 300                                                   &contents, &size))
 301                                         die("could not convert '%s' %s",
 302                                             oid_to_hex(oid), data->rest);
 303                         } else if (opt->cmdmode == 'c') {
 304                                 enum object_type type;
 305                                 if (!textconv_object(data->rest, 0100644, oid,
 306                                                      1, &contents, &size))
 307                                         contents = read_sha1_file(oid->hash, &type,
 308                                                                   &size);
 309                                 if (!contents)
 310                                         die("could not convert '%s' %s",
 311                                             oid_to_hex(oid), data->rest);
 312                         } else
 313                                 die("BUG: invalid cmdmode: %c", opt->cmdmode);
 314                         batch_write(opt, contents, size);
 315                         free(contents);
 316                 } else if (stream_blob_to_fd(1, oid, NULL, 0) < 0)
 317                         die("unable to stream %s to stdout", oid_to_hex(oid));
 318         }
 319         else {
 320                 enum object_type type;
 321                 unsigned long size;
 322                 void *contents;
 323
 324                 contents = read_sha1_file(oid->hash, &type, &size);
 325                 if (!contents)
 326                         die("object %s disappeared", oid_to_hex(oid));
 327                 if (type != data->type)
 328                         die("object %s changed type!?", oid_to_hex(oid));
 329                 if (data->info.sizep && size != data->size)
 330                         die("object %s changed size!?", oid_to_hex(oid));
 331
 332                 batch_write(opt, contents, size);
 333                 free(contents);
 334         }
 335 }
 336
 337 static void batch_object_write(const char *obj_name, struct batch_options *opt,
 338                                struct expand_data *data)
 339 {
 340         struct strbuf buf = STRBUF_INIT;
 341
 342         if (!data->skip_object_info &&
 343             sha1_object_info_extended(data->oid.hash, &data->info,
 344                                       OBJECT_INFO_LOOKUP_REPLACE) < 0) {
 345                 printf("%s missing\n",
 346                        obj_name ? obj_name : oid_to_hex(&data->oid));
 347                 fflush(stdout);
 348                 return;
 349         }
 350
 351         strbuf_expand(&buf, opt->format, expand_format, data);
 352         strbuf_addch(&buf, '\n');
 353         batch_write(opt, buf.buf, buf.len);
 354         strbuf_release(&buf);
 355
 356         if (opt->print_contents) {
 357                 print_object_or_die(opt, data);
 358                 batch_write(opt, "\n", 1);
 359         }
 360 }
 361
 362 static void batch_one_object(const char *obj_name, struct batch_options *opt,
 363                              struct expand_data *data)
 364 {
 365         struct object_context ctx;
 366         int flags = opt->follow_symlinks ? GET_OID_FOLLOW_SYMLINKS : 0;
 367         enum follow_symlinks_result result;
 368
 369         result = get_oid_with_context(obj_name, flags, &data->oid, &ctx);
 370         if (result != FOUND) {
 371                 switch (result) {
 372                 case MISSING_OBJECT:
 373                         printf("%s missing\n", obj_name);
 374                         break;
 375                 case DANGLING_SYMLINK:
 376                         printf("dangling %"PRIuMAX"\n%s\n",
 377                                (uintmax_t)strlen(obj_name), obj_name);
 378                         break;
 379                 case SYMLINK_LOOP:
 380                         printf("loop %"PRIuMAX"\n%s\n",
 381                                (uintmax_t)strlen(obj_name), obj_name);
 382                         break;
 383                 case NOT_DIR:
 384                         printf("notdir %"PRIuMAX"\n%s\n",
 385                                (uintmax_t)strlen(obj_name), obj_name);
 386                         break;
 387                 default:
 388                         die("BUG: unknown get_sha1_with_context result %d\n",
 389                                result);
 390                         break;
 391                 }
 392                 fflush(stdout);
 393                 return;
 394         }
 395
 396         if (ctx.mode == 0) {
 397                 printf("symlink %"PRIuMAX"\n%s\n",
 398                        (uintmax_t)ctx.symlink_path.len,
 399                        ctx.symlink_path.buf);
 400                 fflush(stdout);
 401                 return;
 402         }
 403
 404         batch_object_write(obj_name, opt, data);
 405 }
 406
 407 struct object_cb_data {
 408         struct batch_options *opt;
 409         struct expand_data *expand;
 410 };
 411
 412 static int batch_object_cb(const struct object_id *oid, void *vdata)
 413 {
 414         struct object_cb_data *data = vdata;
 415         oidcpy(&data->expand->oid, oid);
 416         batch_object_write(NULL, data->opt, data->expand);
 417         return 0;
 418 }
 419
 420 static int batch_loose_object(const struct object_id *oid,
 421                               const char *path,
 422                               void *data)
 423 {
 424         oid_array_append(data, oid);
 425         return 0;
 426 }
 427
 428 static int batch_packed_object(const struct object_id *oid,
 429                                struct packed_git *pack,
 430                                uint32_t pos,
 431                                void *data)
 432 {
 433         oid_array_append(data, oid);
 434         return 0;
 435 }
 436
 437 static int batch_objects(struct batch_options *opt)
 438 {
 439         struct strbuf buf = STRBUF_INIT;
 440         struct expand_data data;
 441         int save_warning;
 442         int retval = 0;
 443
 444         if (!opt->format)
 445                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
 446
 447         /*
 448          * Expand once with our special mark_query flag, which will prime the
 449          * object_info to be handed to sha1_object_info_extended for each
 450          * object.
 451          */
 452         memset(&data, 0, sizeof(data));
 453         data.mark_query = 1;
 454         strbuf_expand(&buf, opt->format, expand_format, &data);
 455         data.mark_query = 0;
 456         if (opt->cmdmode)
 457                 data.split_on_whitespace = 1;
 458
 459         if (opt->all_objects) {
 460                 struct object_info empty = OBJECT_INFO_INIT;
 461                 if (!memcmp(&data.info, &empty, sizeof(empty)))
 462                         data.skip_object_info = 1;
 463         }
 464
 465         /*
 466          * If we are printing out the object, then always fill in the type,
 467          * since we will want to decide whether or not to stream.
 468          */
 469         if (opt->print_contents)
 470                 data.info.typep = &data.type;
 471
 472         if (opt->all_objects) {
 473                 struct oid_array sa = OID_ARRAY_INIT;
 474                 struct object_cb_data cb;
 475
 476                 for_each_loose_object(batch_loose_object, &sa, 0);
 477                 for_each_packed_object(batch_packed_object, &sa, 0);
 478
 479                 cb.opt = opt;
 480                 cb.expand = &data;
 481                 oid_array_for_each_unique(&sa, batch_object_cb, &cb);
 482
 483                 oid_array_clear(&sa);
 484                 return 0;
 485         }
 486
 487         /*
 488          * We are going to call get_sha1 on a potentially very large number of
 489          * objects. In most large cases, these will be actual object sha1s. The
 490          * cost to double-check that each one is not also a ref (just so we can
 491          * warn) ends up dwarfing the actual cost of the object lookups
 492          * themselves. We can work around it by just turning off the warning.
 493          */
 494         save_warning = warn_on_object_refname_ambiguity;
 495         warn_on_object_refname_ambiguity = 0;
 496
 497         while (strbuf_getline(&buf, stdin) != EOF) {
 498                 if (data.split_on_whitespace) {
 499                         /*
 500                          * Split at first whitespace, tying off the beginning
 501                          * of the string and saving the remainder (or NULL) in
 502                          * data.rest.
 503                          */
 504                         char *p = strpbrk(buf.buf, " \t");
 505                         if (p) {
 506                                 while (*p && strchr(" \t", *p))
 507                                         *p++ = '\0';
 508                         }
 509                         data.rest = p;
 510                 }
 511
 512                 batch_one_object(buf.buf, opt, &data);
 513         }
 514
 515         strbuf_release(&buf);
 516         warn_on_object_refname_ambiguity = save_warning;
 517         return retval;
 518 }
 519
 520 static const char * const cat_file_usage[] = {
 521         N_("git cat-file (-t [--allow-unknown-type] | -s [--allow-unknown-type] | -e | -p | <type> | --textconv | --filters) [--path=<path>] <object>"),
 522         N_("git cat-file (--batch | --batch-check) [--follow-symlinks] [--textconv | --filters]"),
 523         NULL
 524 };
 525
 526 static int git_cat_file_config(const char *var, const char *value, void *cb)
 527 {
 528         if (userdiff_config(var, value) < 0)
 529                 return -1;
 530
 531         return git_default_config(var, value, cb);
 532 }
 533
 534 static int batch_option_callback(const struct option *opt,
 535                                  const char *arg,
 536                                  int unset)
 537 {
 538         struct batch_options *bo = opt->value;
 539
 540         if (bo->enabled) {
 541                 return 1;
 542         }
 543
 544         bo->enabled = 1;
 545         bo->print_contents = !strcmp(opt->long_name, "batch");
 546         bo->format = arg;
 547
 548         return 0;
 549 }
 550
 551 int cmd_cat_file(int argc, const char **argv, const char *prefix)
 552 {
 553         int opt = 0;
 554         const char *exp_type = NULL, *obj_name = NULL;
 555         struct batch_options batch = {0};
 556         int unknown_type = 0;
 557
 558         const struct option options[] = {
 559                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 560                 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
 561                 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
 562                 OPT_CMDMODE('e', NULL, &opt,
 563                             N_("exit with zero when there's no error"), 'e'),
 564                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 565                 OPT_CMDMODE(0, "textconv", &opt,
 566                             N_("for blob objects, run textconv on object's content"), 'c'),
 567                 OPT_CMDMODE(0, "filters", &opt,
 568                             N_("for blob objects, run filters on object's content"), 'w'),
 569                 OPT_STRING(0, "path", &force_path, N_("blob"),
 570                            N_("use a specific path for --textconv/--filters")),
 571                 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
 572                           N_("allow -s and -t to work with broken/corrupt objects")),
 573                 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
 574                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
 575                         N_("show info and content of objects fed from the standard input"),
 576                         PARSE_OPT_OPTARG, batch_option_callback },
 577                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 578                         N_("show info about objects fed from the standard input"),
 579                         PARSE_OPT_OPTARG, batch_option_callback },
 580                 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
 581                          N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 582                 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
 583                          N_("show all objects with --batch or --batch-check")),
 584                 OPT_END()
 585         };
 586
 587         git_config(git_cat_file_config, NULL);
 588
 589         batch.buffer_output = -1;
 590         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 591
 592         if (opt) {
 593                 if (batch.enabled && (opt == 'c' || opt == 'w'))
 594                         batch.cmdmode = opt;
 595                 else if (argc == 1)
 596                         obj_name = argv[0];
 597                 else
 598                         usage_with_options(cat_file_usage, options);
 599         }
 600         if (!opt && !batch.enabled) {
 601                 if (argc == 2) {
 602                         exp_type = argv[0];
 603                         obj_name = argv[1];
 604                 } else
 605                         usage_with_options(cat_file_usage, options);
 606         }
 607         if (batch.enabled) {
 608                 if (batch.cmdmode != opt || argc)
 609                         usage_with_options(cat_file_usage, options);
 610                 if (batch.cmdmode && batch.all_objects)
 611                         die("--batch-all-objects cannot be combined with "
 612                             "--textconv nor with --filters");
 613         }
 614
 615         if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
 616                 usage_with_options(cat_file_usage, options);
 617         }
 618
 619         if (force_path && opt != 'c' && opt != 'w') {
 620                 error("--path=<path> needs --textconv or --filters");
 621                 usage_with_options(cat_file_usage, options);
 622         }
 623
 624         if (force_path && batch.enabled) {
 625                 error("--path=<path> incompatible with --batch");
 626                 usage_with_options(cat_file_usage, options);
 627         }
 628
 629         if (batch.buffer_output < 0)
 630                 batch.buffer_output = batch.all_objects;
 631
 632         if (batch.enabled)
 633                 return batch_objects(&batch);
 634
 635         if (unknown_type && opt != 't' && opt != 's')
 636                 die("git cat-file --allow-unknown-type: use with -s or -t");
 637         return cat_one_file(opt, exp_type, obj_name, unknown_type);
 638 }