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
  16 struct batch_options {
  17         int enabled;
  18         int follow_symlinks;
  19         int print_contents;
  20         int buffer_output;
  21         int all_objects;
  22         int cmdmode; /* may be 'w' or 'c' for --filters or --textconv */
  23         const char *format;
  24 };
  25
  26 static const char *force_path;
  27
  28 static int filter_object(const char *path, unsigned mode,
  29                          const struct object_id *oid,
  30                          char **buf, unsigned long *size)
  31 {
  32         enum object_type type;
  33
  34         *buf = read_sha1_file(oid->hash, &type, size);
  35         if (!*buf)
  36                 return error(_("cannot read object %s '%s'"),
  37                              oid_to_hex(oid), path);
  38         if ((type == OBJ_BLOB) && S_ISREG(mode)) {
  39                 struct strbuf strbuf = STRBUF_INIT;
  40                 if (convert_to_working_tree(path, *buf, *size, &strbuf)) {
  41                         free(*buf);
  42                         *size = strbuf.len;
  43                         *buf = strbuf_detach(&strbuf, NULL);
  44                 }
  45         }
  46
  47         return 0;
  48 }
  49
  50 static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
  51                         int unknown_type)
  52 {
  53         struct object_id oid;
  54         enum object_type type;
  55         char *buf;
  56         unsigned long size;
  57         struct object_context obj_context;
  58         struct object_info oi = OBJECT_INFO_INIT;
  59         struct strbuf sb = STRBUF_INIT;
  60         unsigned flags = LOOKUP_REPLACE_OBJECT;
  61         const char *path = force_path;
  62
  63         if (unknown_type)
  64                 flags |= LOOKUP_UNKNOWN_OBJECT;
  65
  66         if (get_sha1_with_context(obj_name, GET_SHA1_RECORD_PATH,
  67                                   oid.hash, &obj_context))
  68                 die("Not a valid object name %s", obj_name);
  69
  70         if (!path)
  71                 path = obj_context.path;
  72         if (obj_context.mode == S_IFINVALID)
  73                 obj_context.mode = 0100644;
  74
  75         buf = NULL;
  76         switch (opt) {
  77         case 't':
  78                 oi.typename = &sb;
  79                 if (sha1_object_info_extended(oid.hash, &oi, flags) < 0)
  80                         die("git cat-file: could not get object info");
  81                 if (sb.len) {
  82                         printf("%s\n", sb.buf);
  83                         strbuf_release(&sb);
  84                         return 0;
  85                 }
  86                 break;
  87
  88         case 's':
  89                 oi.sizep = &size;
  90                 if (sha1_object_info_extended(oid.hash, &oi, flags) < 0)
  91                         die("git cat-file: could not get object info");
  92                 printf("%lu\n", size);
  93                 return 0;
  94
  95         case 'e':
  96                 return !has_object_file(&oid);
  97
  98         case 'w':
  99                 if (!path[0])
 100                         die("git cat-file --filters %s: <object> must be "
 101                             "<sha1:path>", obj_name);
 102
 103                 if (filter_object(path, obj_context.mode,
 104                                   &oid, &buf, &size))
 105                         return -1;
 106                 break;
 107
 108         case 'c':
 109                 if (!path[0])
 110                         die("git cat-file --textconv %s: <object> must be <sha1:path>",
 111                             obj_name);
 112
 113                 if (textconv_object(path, obj_context.mode, &oid, 1, &buf, &size))
 114                         break;
 115
 116         case 'p':
 117                 type = sha1_object_info(oid.hash, NULL);
 118                 if (type < 0)
 119                         die("Not a valid object name %s", obj_name);
 120
 121                 /* custom pretty-print here */
 122                 if (type == OBJ_TREE) {
 123                         const char *ls_args[3] = { NULL };
 124                         ls_args[0] =  "ls-tree";
 125                         ls_args[1] =  obj_name;
 126                         return cmd_ls_tree(2, ls_args, NULL);
 127                 }
 128
 129                 if (type == OBJ_BLOB)
 130                         return stream_blob_to_fd(1, &oid, NULL, 0);
 131                 buf = read_sha1_file(oid.hash, &type, &size);
 132                 if (!buf)
 133                         die("Cannot read object %s", obj_name);
 134
 135                 /* otherwise just spit out the data */
 136                 break;
 137
 138         case 0:
 139                 if (type_from_string(exp_type) == OBJ_BLOB) {
 140                         struct object_id blob_oid;
 141                         if (sha1_object_info(oid.hash, NULL) == OBJ_TAG) {
 142                                 char *buffer = read_sha1_file(oid.hash, &type, &size);
 143                                 const char *target;
 144                                 if (!skip_prefix(buffer, "object ", &target) ||
 145                                     get_oid_hex(target, &blob_oid))
 146                                         die("%s not a valid tag", oid_to_hex(&oid));
 147                                 free(buffer);
 148                         } else
 149                                 oidcpy(&blob_oid, &oid);
 150
 151                         if (sha1_object_info(blob_oid.hash, NULL) == OBJ_BLOB)
 152                                 return stream_blob_to_fd(1, &blob_oid, NULL, 0);
 153                         /*
 154                          * we attempted to dereference a tag to a blob
 155                          * and failed; there may be new dereference
 156                          * mechanisms this code is not aware of.
 157                          * fall-back to the usual case.
 158                          */
 159                 }
 160                 buf = read_object_with_reference(oid.hash, exp_type, &size, NULL);
 161                 break;
 162
 163         default:
 164                 die("git cat-file: unknown option: %s", exp_type);
 165         }
 166
 167         if (!buf)
 168                 die("git cat-file %s: bad file", obj_name);
 169
 170         write_or_die(1, buf, size);
 171         free(buf);
 172         free(obj_context.path);
 173         return 0;
 174 }
 175
 176 struct expand_data {
 177         struct object_id oid;
 178         enum object_type type;
 179         unsigned long size;
 180         off_t disk_size;
 181         const char *rest;
 182         struct object_id delta_base_oid;
 183
 184         /*
 185          * If mark_query is true, we do not expand anything, but rather
 186          * just mark the object_info with items we wish to query.
 187          */
 188         int mark_query;
 189
 190         /*
 191          * Whether to split the input on whitespace before feeding it to
 192          * get_sha1; this is decided during the mark_query phase based on
 193          * whether we have a %(rest) token in our format.
 194          */
 195         int split_on_whitespace;
 196
 197         /*
 198          * After a mark_query run, this object_info is set up to be
 199          * passed to sha1_object_info_extended. It will point to the data
 200          * elements above, so you can retrieve the response from there.
 201          */
 202         struct object_info info;
 203
 204         /*
 205          * This flag will be true if the requested batch format and options
 206          * don't require us to call sha1_object_info, which can then be
 207          * optimized out.
 208          */
 209         unsigned skip_object_info : 1;
 210 };
 211
 212 static int is_atom(const char *atom, const char *s, int slen)
 213 {
 214         int alen = strlen(atom);
 215         return alen == slen && !memcmp(atom, s, alen);
 216 }
 217
 218 static void expand_atom(struct strbuf *sb, const char *atom, int len,
 219                         void *vdata)
 220 {
 221         struct expand_data *data = vdata;
 222
 223         if (is_atom("objectname", atom, len)) {
 224                 if (!data->mark_query)
 225                         strbuf_addstr(sb, oid_to_hex(&data->oid));
 226         } else if (is_atom("objecttype", atom, len)) {
 227                 if (data->mark_query)
 228                         data->info.typep = &data->type;
 229                 else
 230                         strbuf_addstr(sb, typename(data->type));
 231         } else if (is_atom("objectsize", atom, len)) {
 232                 if (data->mark_query)
 233                         data->info.sizep = &data->size;
 234                 else
 235                         strbuf_addf(sb, "%lu", data->size);
 236         } else if (is_atom("objectsize:disk", atom, len)) {
 237                 if (data->mark_query)
 238                         data->info.disk_sizep = &data->disk_size;
 239                 else
 240                         strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
 241         } else if (is_atom("rest", atom, len)) {
 242                 if (data->mark_query)
 243                         data->split_on_whitespace = 1;
 244                 else if (data->rest)
 245                         strbuf_addstr(sb, data->rest);
 246         } else if (is_atom("deltabase", atom, len)) {
 247                 if (data->mark_query)
 248                         data->info.delta_base_sha1 = data->delta_base_oid.hash;
 249                 else
 250                         strbuf_addstr(sb,
 251                                       oid_to_hex(&data->delta_base_oid));
 252         } else
 253                 die("unknown format element: %.*s", len, atom);
 254 }
 255
 256 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 257 {
 258         const char *end;
 259
 260         if (*start != '(')
 261                 return 0;
 262         end = strchr(start + 1, ')');
 263         if (!end)
 264                 die("format element '%s' does not end in ')'", start);
 265
 266         expand_atom(sb, start + 1, end - start - 1, data);
 267
 268         return end - start + 1;
 269 }
 270
 271 static void batch_write(struct batch_options *opt, const void *data, int len)
 272 {
 273         if (opt->buffer_output) {
 274                 if (fwrite(data, 1, len, stdout) != len)
 275                         die_errno("unable to write to stdout");
 276         } else
 277                 write_or_die(1, data, len);
 278 }
 279
 280 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
 281 {
 282         const struct object_id *oid = &data->oid;
 283
 284         assert(data->info.typep);
 285
 286         if (data->type == OBJ_BLOB) {
 287                 if (opt->buffer_output)
 288                         fflush(stdout);
 289                 if (opt->cmdmode) {
 290                         char *contents;
 291                         unsigned long size;
 292
 293                         if (!data->rest)
 294                                 die("missing path for '%s'", oid_to_hex(oid));
 295
 296                         if (opt->cmdmode == 'w') {
 297                                 if (filter_object(data->rest, 0100644, oid,
 298                                                   &contents, &size))
 299                                         die("could not convert '%s' %s",
 300                                             oid_to_hex(oid), data->rest);
 301                         } else if (opt->cmdmode == 'c') {
 302                                 enum object_type type;
 303                                 if (!textconv_object(data->rest, 0100644, oid,
 304                                                      1, &contents, &size))
 305                                         contents = read_sha1_file(oid->hash, &type,
 306                                                                   &size);
 307                                 if (!contents)
 308                                         die("could not convert '%s' %s",
 309                                             oid_to_hex(oid), data->rest);
 310                         } else
 311                                 die("BUG: invalid cmdmode: %c", opt->cmdmode);
 312                         batch_write(opt, contents, size);
 313                         free(contents);
 314                 } else if (stream_blob_to_fd(1, oid, NULL, 0) < 0)
 315                         die("unable to stream %s to stdout", oid_to_hex(oid));
 316         }
 317         else {
 318                 enum object_type type;
 319                 unsigned long size;
 320                 void *contents;
 321
 322                 contents = read_sha1_file(oid->hash, &type, &size);
 323                 if (!contents)
 324                         die("object %s disappeared", oid_to_hex(oid));
 325                 if (type != data->type)
 326                         die("object %s changed type!?", oid_to_hex(oid));
 327                 if (data->info.sizep && size != data->size)
 328                         die("object %s changed size!?", oid_to_hex(oid));
 329
 330                 batch_write(opt, contents, size);
 331                 free(contents);
 332         }
 333 }
 334
 335 static void batch_object_write(const char *obj_name, struct batch_options *opt,
 336                                struct expand_data *data)
 337 {
 338         struct strbuf buf = STRBUF_INIT;
 339
 340         if (!data->skip_object_info &&
 341             sha1_object_info_extended(data->oid.hash, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
 342                 printf("%s missing\n",
 343                        obj_name ? obj_name : oid_to_hex(&data->oid));
 344                 fflush(stdout);
 345                 return;
 346         }
 347
 348         strbuf_expand(&buf, opt->format, expand_format, data);
 349         strbuf_addch(&buf, '\n');
 350         batch_write(opt, buf.buf, buf.len);
 351         strbuf_release(&buf);
 352
 353         if (opt->print_contents) {
 354                 print_object_or_die(opt, data);
 355                 batch_write(opt, "\n", 1);
 356         }
 357 }
 358
 359 static void batch_one_object(const char *obj_name, struct batch_options *opt,
 360                              struct expand_data *data)
 361 {
 362         struct object_context ctx;
 363         int flags = opt->follow_symlinks ? GET_SHA1_FOLLOW_SYMLINKS : 0;
 364         enum follow_symlinks_result result;
 365
 366         result = get_sha1_with_context(obj_name, flags, data->oid.hash, &ctx);
 367         if (result != FOUND) {
 368                 switch (result) {
 369                 case MISSING_OBJECT:
 370                         printf("%s missing\n", obj_name);
 371                         break;
 372                 case DANGLING_SYMLINK:
 373                         printf("dangling %"PRIuMAX"\n%s\n",
 374                                (uintmax_t)strlen(obj_name), obj_name);
 375                         break;
 376                 case SYMLINK_LOOP:
 377                         printf("loop %"PRIuMAX"\n%s\n",
 378                                (uintmax_t)strlen(obj_name), obj_name);
 379                         break;
 380                 case NOT_DIR:
 381                         printf("notdir %"PRIuMAX"\n%s\n",
 382                                (uintmax_t)strlen(obj_name), obj_name);
 383                         break;
 384                 default:
 385                         die("BUG: unknown get_sha1_with_context result %d\n",
 386                                result);
 387                         break;
 388                 }
 389                 fflush(stdout);
 390                 return;
 391         }
 392
 393         if (ctx.mode == 0) {
 394                 printf("symlink %"PRIuMAX"\n%s\n",
 395                        (uintmax_t)ctx.symlink_path.len,
 396                        ctx.symlink_path.buf);
 397                 fflush(stdout);
 398                 return;
 399         }
 400
 401         batch_object_write(obj_name, opt, data);
 402 }
 403
 404 struct object_cb_data {
 405         struct batch_options *opt;
 406         struct expand_data *expand;
 407 };
 408
 409 static int batch_object_cb(const struct object_id *oid, void *vdata)
 410 {
 411         struct object_cb_data *data = vdata;
 412         oidcpy(&data->expand->oid, oid);
 413         batch_object_write(NULL, data->opt, data->expand);
 414         return 0;
 415 }
 416
 417 static int batch_loose_object(const struct object_id *oid,
 418                               const char *path,
 419                               void *data)
 420 {
 421         oid_array_append(data, oid);
 422         return 0;
 423 }
 424
 425 static int batch_packed_object(const struct object_id *oid,
 426                                struct packed_git *pack,
 427                                uint32_t pos,
 428                                void *data)
 429 {
 430         oid_array_append(data, oid);
 431         return 0;
 432 }
 433
 434 static int batch_objects(struct batch_options *opt)
 435 {
 436         struct strbuf buf = STRBUF_INIT;
 437         struct expand_data data;
 438         int save_warning;
 439         int retval = 0;
 440
 441         if (!opt->format)
 442                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
 443
 444         /*
 445          * Expand once with our special mark_query flag, which will prime the
 446          * object_info to be handed to sha1_object_info_extended for each
 447          * object.
 448          */
 449         memset(&data, 0, sizeof(data));
 450         data.mark_query = 1;
 451         strbuf_expand(&buf, opt->format, expand_format, &data);
 452         data.mark_query = 0;
 453         if (opt->cmdmode)
 454                 data.split_on_whitespace = 1;
 455
 456         if (opt->all_objects) {
 457                 struct object_info empty = OBJECT_INFO_INIT;
 458                 if (!memcmp(&data.info, &empty, sizeof(empty)))
 459                         data.skip_object_info = 1;
 460         }
 461
 462         /*
 463          * If we are printing out the object, then always fill in the type,
 464          * since we will want to decide whether or not to stream.
 465          */
 466         if (opt->print_contents)
 467                 data.info.typep = &data.type;
 468
 469         if (opt->all_objects) {
 470                 struct oid_array sa = OID_ARRAY_INIT;
 471                 struct object_cb_data cb;
 472
 473                 for_each_loose_object(batch_loose_object, &sa, 0);
 474                 for_each_packed_object(batch_packed_object, &sa, 0);
 475
 476                 cb.opt = opt;
 477                 cb.expand = &data;
 478                 oid_array_for_each_unique(&sa, batch_object_cb, &cb);
 479
 480                 oid_array_clear(&sa);
 481                 return 0;
 482         }
 483
 484         /*
 485          * We are going to call get_sha1 on a potentially very large number of
 486          * objects. In most large cases, these will be actual object sha1s. The
 487          * cost to double-check that each one is not also a ref (just so we can
 488          * warn) ends up dwarfing the actual cost of the object lookups
 489          * themselves. We can work around it by just turning off the warning.
 490          */
 491         save_warning = warn_on_object_refname_ambiguity;
 492         warn_on_object_refname_ambiguity = 0;
 493
 494         while (strbuf_getline(&buf, stdin) != EOF) {
 495                 if (data.split_on_whitespace) {
 496                         /*
 497                          * Split at first whitespace, tying off the beginning
 498                          * of the string and saving the remainder (or NULL) in
 499                          * data.rest.
 500                          */
 501                         char *p = strpbrk(buf.buf, " \t");
 502                         if (p) {
 503                                 while (*p && strchr(" \t", *p))
 504                                         *p++ = '\0';
 505                         }
 506                         data.rest = p;
 507                 }
 508
 509                 batch_one_object(buf.buf, opt, &data);
 510         }
 511
 512         strbuf_release(&buf);
 513         warn_on_object_refname_ambiguity = save_warning;
 514         return retval;
 515 }
 516
 517 static const char * const cat_file_usage[] = {
 518         N_("git cat-file (-t [--allow-unknown-type] | -s [--allow-unknown-type] | -e | -p | <type> | --textconv | --filters) [--path=<path>] <object>"),
 519         N_("git cat-file (--batch | --batch-check) [--follow-symlinks] [--textconv | --filters]"),
 520         NULL
 521 };
 522
 523 static int git_cat_file_config(const char *var, const char *value, void *cb)
 524 {
 525         if (userdiff_config(var, value) < 0)
 526                 return -1;
 527
 528         return git_default_config(var, value, cb);
 529 }
 530
 531 static int batch_option_callback(const struct option *opt,
 532                                  const char *arg,
 533                                  int unset)
 534 {
 535         struct batch_options *bo = opt->value;
 536
 537         if (bo->enabled) {
 538                 return 1;
 539         }
 540
 541         bo->enabled = 1;
 542         bo->print_contents = !strcmp(opt->long_name, "batch");
 543         bo->format = arg;
 544
 545         return 0;
 546 }
 547
 548 int cmd_cat_file(int argc, const char **argv, const char *prefix)
 549 {
 550         int opt = 0;
 551         const char *exp_type = NULL, *obj_name = NULL;
 552         struct batch_options batch = {0};
 553         int unknown_type = 0;
 554
 555         const struct option options[] = {
 556                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 557                 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
 558                 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
 559                 OPT_CMDMODE('e', NULL, &opt,
 560                             N_("exit with zero when there's no error"), 'e'),
 561                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 562                 OPT_CMDMODE(0, "textconv", &opt,
 563                             N_("for blob objects, run textconv on object's content"), 'c'),
 564                 OPT_CMDMODE(0, "filters", &opt,
 565                             N_("for blob objects, run filters on object's content"), 'w'),
 566                 OPT_STRING(0, "path", &force_path, N_("blob"),
 567                            N_("use a specific path for --textconv/--filters")),
 568                 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
 569                           N_("allow -s and -t to work with broken/corrupt objects")),
 570                 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
 571                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
 572                         N_("show info and content of objects fed from the standard input"),
 573                         PARSE_OPT_OPTARG, batch_option_callback },
 574                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 575                         N_("show info about objects fed from the standard input"),
 576                         PARSE_OPT_OPTARG, batch_option_callback },
 577                 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
 578                          N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 579                 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
 580                          N_("show all objects with --batch or --batch-check")),
 581                 OPT_END()
 582         };
 583
 584         git_config(git_cat_file_config, NULL);
 585
 586         batch.buffer_output = -1;
 587         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 588
 589         if (opt) {
 590                 if (batch.enabled && (opt == 'c' || opt == 'w'))
 591                         batch.cmdmode = opt;
 592                 else if (argc == 1)
 593                         obj_name = argv[0];
 594                 else
 595                         usage_with_options(cat_file_usage, options);
 596         }
 597         if (!opt && !batch.enabled) {
 598                 if (argc == 2) {
 599                         exp_type = argv[0];
 600                         obj_name = argv[1];
 601                 } else
 602                         usage_with_options(cat_file_usage, options);
 603         }
 604         if (batch.enabled) {
 605                 if (batch.cmdmode != opt || argc)
 606                         usage_with_options(cat_file_usage, options);
 607                 if (batch.cmdmode && batch.all_objects)
 608                         die("--batch-all-objects cannot be combined with "
 609                             "--textconv nor with --filters");
 610         }
 611
 612         if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
 613                 usage_with_options(cat_file_usage, options);
 614         }
 615
 616         if (force_path && opt != 'c' && opt != 'w') {
 617                 error("--path=<path> needs --textconv or --filters");
 618                 usage_with_options(cat_file_usage, options);
 619         }
 620
 621         if (force_path && batch.enabled) {
 622                 error("--path=<path> incompatible with --batch");
 623                 usage_with_options(cat_file_usage, options);
 624         }
 625
 626         if (batch.buffer_output < 0)
 627                 batch.buffer_output = batch.all_objects;
 628
 629         if (batch.enabled)
 630                 return batch_objects(&batch);
 631
 632         if (unknown_type && opt != 't' && opt != 's')
 633                 die("git cat-file --allow-unknown-type: use with -s or -t");
 634         return cat_one_file(opt, exp_type, obj_name, unknown_type);
 635 }