git.oblomov.eu Git - git/blob - 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 "builtin.h"
   8 #include "parse-options.h"
   9 #include "userdiff.h"
  10 #include "streaming.h"
  11 #include "tree-walk.h"
  12 #include "sha1-array.h"
  13
  14 struct batch_options {
  15         int enabled;
  16         int follow_symlinks;
  17         int print_contents;
  18         int buffer_output;
  19         int all_objects;
  20         const char *format;
  21 };
  22
  23 static const char *force_path;
  24
  25 static int filter_object(const char *path, unsigned mode,
  26                          const unsigned char *sha1,
  27                          char **buf, unsigned long *size)
  28 {
  29         enum object_type type;
  30
  31         *buf = read_sha1_file(sha1, &type, size);
  32         if (!*buf)
  33                 return error(_("cannot read object %s '%s'"),
  34                         sha1_to_hex(sha1), path);
  35         if ((type == OBJ_BLOB) && S_ISREG(mode)) {
  36                 struct strbuf strbuf = STRBUF_INIT;
  37                 if (convert_to_working_tree(path, *buf, *size, &strbuf)) {
  38                         free(*buf);
  39                         *size = strbuf.len;
  40                         *buf = strbuf_detach(&strbuf, NULL);
  41                 }
  42         }
  43
  44         return 0;
  45 }
  46
  47 static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
  48                         int unknown_type)
  49 {
  50         unsigned char sha1[20];
  51         enum object_type type;
  52         char *buf;
  53         unsigned long size;
  54         struct object_context obj_context;
  55         struct object_info oi = {NULL};
  56         struct strbuf sb = STRBUF_INIT;
  57         unsigned flags = LOOKUP_REPLACE_OBJECT;
  58         const char *path = force_path;
  59
  60         if (unknown_type)
  61                 flags |= LOOKUP_UNKNOWN_OBJECT;
  62
  63         if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
  64                 die("Not a valid object name %s", obj_name);
  65
  66         if (!path)
  67                 path = obj_context.path;
  68         if (obj_context.mode == S_IFINVALID)
  69                 obj_context.mode = 0100644;
  70
  71         buf = NULL;
  72         switch (opt) {
  73         case 't':
  74                 oi.typename = &sb;
  75                 if (sha1_object_info_extended(sha1, &oi, flags) < 0)
  76                         die("git cat-file: could not get object info");
  77                 if (sb.len) {
  78                         printf("%s\n", sb.buf);
  79                         strbuf_release(&sb);
  80                         return 0;
  81                 }
  82                 break;
  83
  84         case 's':
  85                 oi.sizep = &size;
  86                 if (sha1_object_info_extended(sha1, &oi, flags) < 0)
  87                         die("git cat-file: could not get object info");
  88                 printf("%lu\n", size);
  89                 return 0;
  90
  91         case 'e':
  92                 return !has_sha1_file(sha1);
  93
  94         case 'w':
  95                 if (!path[0])
  96                         die("git cat-file --filters %s: <object> must be "
  97                             "<sha1:path>", obj_name);
  98
  99                 if (filter_object(path, obj_context.mode,
 100                                   sha1, &buf, &size))
 101                         return -1;
 102                 break;
 103
 104         case 'c':
 105                 if (!path[0])
 106                         die("git cat-file --textconv %s: <object> must be <sha1:path>",
 107                             obj_name);
 108
 109                 if (textconv_object(path, obj_context.mode,
 110                                     sha1, 1, &buf, &size))
 111                         break;
 112
 113         case 'p':
 114                 type = sha1_object_info(sha1, NULL);
 115                 if (type < 0)
 116                         die("Not a valid object name %s", obj_name);
 117
 118                 /* custom pretty-print here */
 119                 if (type == OBJ_TREE) {
 120                         const char *ls_args[3] = { NULL };
 121                         ls_args[0] =  "ls-tree";
 122                         ls_args[1] =  obj_name;
 123                         return cmd_ls_tree(2, ls_args, NULL);
 124                 }
 125
 126                 if (type == OBJ_BLOB)
 127                         return stream_blob_to_fd(1, sha1, NULL, 0);
 128                 buf = read_sha1_file(sha1, &type, &size);
 129                 if (!buf)
 130                         die("Cannot read object %s", obj_name);
 131
 132                 /* otherwise just spit out the data */
 133                 break;
 134
 135         case 0:
 136                 if (type_from_string(exp_type) == OBJ_BLOB) {
 137                         unsigned char blob_sha1[20];
 138                         if (sha1_object_info(sha1, NULL) == OBJ_TAG) {
 139                                 char *buffer = read_sha1_file(sha1, &type, &size);
 140                                 const char *target;
 141                                 if (!skip_prefix(buffer, "object ", &target) ||
 142                                     get_sha1_hex(target, blob_sha1))
 143                                         die("%s not a valid tag", sha1_to_hex(sha1));
 144                                 free(buffer);
 145                         } else
 146                                 hashcpy(blob_sha1, sha1);
 147
 148                         if (sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
 149                                 return stream_blob_to_fd(1, blob_sha1, NULL, 0);
 150                         /*
 151                          * we attempted to dereference a tag to a blob
 152                          * and failed; there may be new dereference
 153                          * mechanisms this code is not aware of.
 154                          * fall-back to the usual case.
 155                          */
 156                 }
 157                 buf = read_object_with_reference(sha1, exp_type, &size, NULL);
 158                 break;
 159
 160         default:
 161                 die("git cat-file: unknown option: %s", exp_type);
 162         }
 163
 164         if (!buf)
 165                 die("git cat-file %s: bad file", obj_name);
 166
 167         write_or_die(1, buf, size);
 168         return 0;
 169 }
 170
 171 struct expand_data {
 172         unsigned char sha1[20];
 173         enum object_type type;
 174         unsigned long size;
 175         off_t disk_size;
 176         const char *rest;
 177         unsigned char delta_base_sha1[20];
 178
 179         /*
 180          * If mark_query is true, we do not expand anything, but rather
 181          * just mark the object_info with items we wish to query.
 182          */
 183         int mark_query;
 184
 185         /*
 186          * Whether to split the input on whitespace before feeding it to
 187          * get_sha1; this is decided during the mark_query phase based on
 188          * whether we have a %(rest) token in our format.
 189          */
 190         int split_on_whitespace;
 191
 192         /*
 193          * After a mark_query run, this object_info is set up to be
 194          * passed to sha1_object_info_extended. It will point to the data
 195          * elements above, so you can retrieve the response from there.
 196          */
 197         struct object_info info;
 198
 199         /*
 200          * This flag will be true if the requested batch format and options
 201          * don't require us to call sha1_object_info, which can then be
 202          * optimized out.
 203          */
 204         unsigned skip_object_info : 1;
 205 };
 206
 207 static int is_atom(const char *atom, const char *s, int slen)
 208 {
 209         int alen = strlen(atom);
 210         return alen == slen && !memcmp(atom, s, alen);
 211 }
 212
 213 static void expand_atom(struct strbuf *sb, const char *atom, int len,
 214                         void *vdata)
 215 {
 216         struct expand_data *data = vdata;
 217
 218         if (is_atom("objectname", atom, len)) {
 219                 if (!data->mark_query)
 220                         strbuf_addstr(sb, sha1_to_hex(data->sha1));
 221         } else if (is_atom("objecttype", atom, len)) {
 222                 if (data->mark_query)
 223                         data->info.typep = &data->type;
 224                 else
 225                         strbuf_addstr(sb, typename(data->type));
 226         } else if (is_atom("objectsize", atom, len)) {
 227                 if (data->mark_query)
 228                         data->info.sizep = &data->size;
 229                 else
 230                         strbuf_addf(sb, "%lu", data->size);
 231         } else if (is_atom("objectsize:disk", atom, len)) {
 232                 if (data->mark_query)
 233                         data->info.disk_sizep = &data->disk_size;
 234                 else
 235                         strbuf_addf(sb, "%"PRIuMAX, (uintmax_t)data->disk_size);
 236         } else if (is_atom("rest", atom, len)) {
 237                 if (data->mark_query)
 238                         data->split_on_whitespace = 1;
 239                 else if (data->rest)
 240                         strbuf_addstr(sb, data->rest);
 241         } else if (is_atom("deltabase", atom, len)) {
 242                 if (data->mark_query)
 243                         data->info.delta_base_sha1 = data->delta_base_sha1;
 244                 else
 245                         strbuf_addstr(sb, sha1_to_hex(data->delta_base_sha1));
 246         } else
 247                 die("unknown format element: %.*s", len, atom);
 248 }
 249
 250 static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 251 {
 252         const char *end;
 253
 254         if (*start != '(')
 255                 return 0;
 256         end = strchr(start + 1, ')');
 257         if (!end)
 258                 die("format element '%s' does not end in ')'", start);
 259
 260         expand_atom(sb, start + 1, end - start - 1, data);
 261
 262         return end - start + 1;
 263 }
 264
 265 static void batch_write(struct batch_options *opt, const void *data, int len)
 266 {
 267         if (opt->buffer_output) {
 268                 if (fwrite(data, 1, len, stdout) != len)
 269                         die_errno("unable to write to stdout");
 270         } else
 271                 write_or_die(1, data, len);
 272 }
 273
 274 static void print_object_or_die(struct batch_options *opt, struct expand_data *data)
 275 {
 276         const unsigned char *sha1 = data->sha1;
 277
 278         assert(data->info.typep);
 279
 280         if (data->type == OBJ_BLOB) {
 281                 if (opt->buffer_output)
 282                         fflush(stdout);
 283                 if (stream_blob_to_fd(1, sha1, NULL, 0) < 0)
 284                         die("unable to stream %s to stdout", sha1_to_hex(sha1));
 285         }
 286         else {
 287                 enum object_type type;
 288                 unsigned long size;
 289                 void *contents;
 290
 291                 contents = read_sha1_file(sha1, &type, &size);
 292                 if (!contents)
 293                         die("object %s disappeared", sha1_to_hex(sha1));
 294                 if (type != data->type)
 295                         die("object %s changed type!?", sha1_to_hex(sha1));
 296                 if (data->info.sizep && size != data->size)
 297                         die("object %s changed size!?", sha1_to_hex(sha1));
 298
 299                 batch_write(opt, contents, size);
 300                 free(contents);
 301         }
 302 }
 303
 304 static void batch_object_write(const char *obj_name, struct batch_options *opt,
 305                                struct expand_data *data)
 306 {
 307         struct strbuf buf = STRBUF_INIT;
 308
 309         if (!data->skip_object_info &&
 310             sha1_object_info_extended(data->sha1, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
 311                 printf("%s missing\n", obj_name ? obj_name : sha1_to_hex(data->sha1));
 312                 fflush(stdout);
 313                 return;
 314         }
 315
 316         strbuf_expand(&buf, opt->format, expand_format, data);
 317         strbuf_addch(&buf, '\n');
 318         batch_write(opt, buf.buf, buf.len);
 319         strbuf_release(&buf);
 320
 321         if (opt->print_contents) {
 322                 print_object_or_die(opt, data);
 323                 batch_write(opt, "\n", 1);
 324         }
 325 }
 326
 327 static void batch_one_object(const char *obj_name, struct batch_options *opt,
 328                              struct expand_data *data)
 329 {
 330         struct object_context ctx;
 331         int flags = opt->follow_symlinks ? GET_SHA1_FOLLOW_SYMLINKS : 0;
 332         enum follow_symlinks_result result;
 333
 334         result = get_sha1_with_context(obj_name, flags, data->sha1, &ctx);
 335         if (result != FOUND) {
 336                 switch (result) {
 337                 case MISSING_OBJECT:
 338                         printf("%s missing\n", obj_name);
 339                         break;
 340                 case DANGLING_SYMLINK:
 341                         printf("dangling %"PRIuMAX"\n%s\n",
 342                                (uintmax_t)strlen(obj_name), obj_name);
 343                         break;
 344                 case SYMLINK_LOOP:
 345                         printf("loop %"PRIuMAX"\n%s\n",
 346                                (uintmax_t)strlen(obj_name), obj_name);
 347                         break;
 348                 case NOT_DIR:
 349                         printf("notdir %"PRIuMAX"\n%s\n",
 350                                (uintmax_t)strlen(obj_name), obj_name);
 351                         break;
 352                 default:
 353                         die("BUG: unknown get_sha1_with_context result %d\n",
 354                                result);
 355                         break;
 356                 }
 357                 fflush(stdout);
 358                 return;
 359         }
 360
 361         if (ctx.mode == 0) {
 362                 printf("symlink %"PRIuMAX"\n%s\n",
 363                        (uintmax_t)ctx.symlink_path.len,
 364                        ctx.symlink_path.buf);
 365                 fflush(stdout);
 366                 return;
 367         }
 368
 369         batch_object_write(obj_name, opt, data);
 370 }
 371
 372 struct object_cb_data {
 373         struct batch_options *opt;
 374         struct expand_data *expand;
 375 };
 376
 377 static void batch_object_cb(const unsigned char sha1[20], void *vdata)
 378 {
 379         struct object_cb_data *data = vdata;
 380         hashcpy(data->expand->sha1, sha1);
 381         batch_object_write(NULL, data->opt, data->expand);
 382 }
 383
 384 static int batch_loose_object(const unsigned char *sha1,
 385                               const char *path,
 386                               void *data)
 387 {
 388         sha1_array_append(data, sha1);
 389         return 0;
 390 }
 391
 392 static int batch_packed_object(const unsigned char *sha1,
 393                                struct packed_git *pack,
 394                                uint32_t pos,
 395                                void *data)
 396 {
 397         sha1_array_append(data, sha1);
 398         return 0;
 399 }
 400
 401 static int batch_objects(struct batch_options *opt)
 402 {
 403         struct strbuf buf = STRBUF_INIT;
 404         struct expand_data data;
 405         int save_warning;
 406         int retval = 0;
 407
 408         if (!opt->format)
 409                 opt->format = "%(objectname) %(objecttype) %(objectsize)";
 410
 411         /*
 412          * Expand once with our special mark_query flag, which will prime the
 413          * object_info to be handed to sha1_object_info_extended for each
 414          * object.
 415          */
 416         memset(&data, 0, sizeof(data));
 417         data.mark_query = 1;
 418         strbuf_expand(&buf, opt->format, expand_format, &data);
 419         data.mark_query = 0;
 420
 421         if (opt->all_objects) {
 422                 struct object_info empty;
 423                 memset(&empty, 0, sizeof(empty));
 424                 if (!memcmp(&data.info, &empty, sizeof(empty)))
 425                         data.skip_object_info = 1;
 426         }
 427
 428         /*
 429          * If we are printing out the object, then always fill in the type,
 430          * since we will want to decide whether or not to stream.
 431          */
 432         if (opt->print_contents)
 433                 data.info.typep = &data.type;
 434
 435         if (opt->all_objects) {
 436                 struct sha1_array sa = SHA1_ARRAY_INIT;
 437                 struct object_cb_data cb;
 438
 439                 for_each_loose_object(batch_loose_object, &sa, 0);
 440                 for_each_packed_object(batch_packed_object, &sa, 0);
 441
 442                 cb.opt = opt;
 443                 cb.expand = &data;
 444                 sha1_array_for_each_unique(&sa, batch_object_cb, &cb);
 445
 446                 sha1_array_clear(&sa);
 447                 return 0;
 448         }
 449
 450         /*
 451          * We are going to call get_sha1 on a potentially very large number of
 452          * objects. In most large cases, these will be actual object sha1s. The
 453          * cost to double-check that each one is not also a ref (just so we can
 454          * warn) ends up dwarfing the actual cost of the object lookups
 455          * themselves. We can work around it by just turning off the warning.
 456          */
 457         save_warning = warn_on_object_refname_ambiguity;
 458         warn_on_object_refname_ambiguity = 0;
 459
 460         while (strbuf_getline(&buf, stdin) != EOF) {
 461                 if (data.split_on_whitespace) {
 462                         /*
 463                          * Split at first whitespace, tying off the beginning
 464                          * of the string and saving the remainder (or NULL) in
 465                          * data.rest.
 466                          */
 467                         char *p = strpbrk(buf.buf, " \t");
 468                         if (p) {
 469                                 while (*p && strchr(" \t", *p))
 470                                         *p++ = '\0';
 471                         }
 472                         data.rest = p;
 473                 }
 474
 475                 batch_one_object(buf.buf, opt, &data);
 476         }
 477
 478         strbuf_release(&buf);
 479         warn_on_object_refname_ambiguity = save_warning;
 480         return retval;
 481 }
 482
 483 static const char * const cat_file_usage[] = {
 484         N_("git cat-file (-t [--allow-unknown-type]|-s [--allow-unknown-type]|-e|-p|<type>|--textconv|--filters) [--path=<path>] <object>"),
 485         N_("git cat-file (--batch | --batch-check) [--follow-symlinks]"),
 486         NULL
 487 };
 488
 489 static int git_cat_file_config(const char *var, const char *value, void *cb)
 490 {
 491         if (userdiff_config(var, value) < 0)
 492                 return -1;
 493
 494         return git_default_config(var, value, cb);
 495 }
 496
 497 static int batch_option_callback(const struct option *opt,
 498                                  const char *arg,
 499                                  int unset)
 500 {
 501         struct batch_options *bo = opt->value;
 502
 503         if (bo->enabled) {
 504                 return 1;
 505         }
 506
 507         bo->enabled = 1;
 508         bo->print_contents = !strcmp(opt->long_name, "batch");
 509         bo->format = arg;
 510
 511         return 0;
 512 }
 513
 514 int cmd_cat_file(int argc, const char **argv, const char *prefix)
 515 {
 516         int opt = 0;
 517         const char *exp_type = NULL, *obj_name = NULL;
 518         struct batch_options batch = {0};
 519         int unknown_type = 0;
 520
 521         const struct option options[] = {
 522                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 523                 OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
 524                 OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
 525                 OPT_CMDMODE('e', NULL, &opt,
 526                             N_("exit with zero when there's no error"), 'e'),
 527                 OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 528                 OPT_CMDMODE(0, "textconv", &opt,
 529                             N_("for blob objects, run textconv on object's content"), 'c'),
 530                 OPT_CMDMODE(0, "filters", &opt,
 531                             N_("for blob objects, run filters on object's content"), 'w'),
 532                 OPT_STRING(0, "path", &force_path, N_("blob"),
 533                            N_("use a specific path for --textconv/--filters")),
 534                 OPT_BOOL(0, "allow-unknown-type", &unknown_type,
 535                           N_("allow -s and -t to work with broken/corrupt objects")),
 536                 OPT_BOOL(0, "buffer", &batch.buffer_output, N_("buffer --batch output")),
 537                 { OPTION_CALLBACK, 0, "batch", &batch, "format",
 538                         N_("show info and content of objects fed from the standard input"),
 539                         PARSE_OPT_OPTARG, batch_option_callback },
 540                 { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 541                         N_("show info about objects fed from the standard input"),
 542                         PARSE_OPT_OPTARG, batch_option_callback },
 543                 OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
 544                          N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 545                 OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
 546                          N_("show all objects with --batch or --batch-check")),
 547                 OPT_END()
 548         };
 549
 550         git_config(git_cat_file_config, NULL);
 551
 552         batch.buffer_output = -1;
 553         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 554
 555         if (opt) {
 556                 if (argc == 1)
 557                         obj_name = argv[0];
 558                 else
 559                         usage_with_options(cat_file_usage, options);
 560         }
 561         if (!opt && !batch.enabled) {
 562                 if (argc == 2) {
 563                         exp_type = argv[0];
 564                         obj_name = argv[1];
 565                 } else
 566                         usage_with_options(cat_file_usage, options);
 567         }
 568         if (batch.enabled && (opt || argc)) {
 569                 usage_with_options(cat_file_usage, options);
 570         }
 571
 572         if ((batch.follow_symlinks || batch.all_objects) && !batch.enabled) {
 573                 usage_with_options(cat_file_usage, options);
 574         }
 575
 576         if (force_path && opt != 'c' && opt != 'w') {
 577                 error("--path=<path> needs --textconv or --filters");
 578                 usage_with_options(cat_file_usage, options);
 579         }
 580
 581         if (batch.buffer_output < 0)
 582                 batch.buffer_output = batch.all_objects;
 583
 584         if (batch.enabled)
 585                 return batch_objects(&batch);
 586
 587         if (unknown_type && opt != 't' && opt != 's')
 588                 die("git cat-file --allow-unknown-type: use with -s or -t");
 589         return cat_one_file(opt, exp_type, obj_name, unknown_type);
 590 }