builtin / cat-file.con commit Merge branch 'bc/gpg-verify-raw' (ba12cb2)
   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
  13static int cat_one_file(int opt, const char *exp_type, const char *obj_name,
  14                        int unknown_type)
  15{
  16        unsigned char sha1[20];
  17        enum object_type type;
  18        char *buf;
  19        unsigned long size;
  20        struct object_context obj_context;
  21        struct object_info oi = {NULL};
  22        struct strbuf sb = STRBUF_INIT;
  23        unsigned flags = LOOKUP_REPLACE_OBJECT;
  24
  25        if (unknown_type)
  26                flags |= LOOKUP_UNKNOWN_OBJECT;
  27
  28        if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
  29                die("Not a valid object name %s", obj_name);
  30
  31        buf = NULL;
  32        switch (opt) {
  33        case 't':
  34                oi.typename = &sb;
  35                if (sha1_object_info_extended(sha1, &oi, flags) < 0)
  36                        die("git cat-file: could not get object info");
  37                if (sb.len) {
  38                        printf("%s\n", sb.buf);
  39                        strbuf_release(&sb);
  40                        return 0;
  41                }
  42                break;
  43
  44        case 's':
  45                oi.sizep = &size;
  46                if (sha1_object_info_extended(sha1, &oi, flags) < 0)
  47                        die("git cat-file: could not get object info");
  48                printf("%lu\n", size);
  49                return 0;
  50
  51        case 'e':
  52                return !has_sha1_file(sha1);
  53
  54        case 'c':
  55                if (!obj_context.path[0])
  56                        die("git cat-file --textconv %s: <object> must be <sha1:path>",
  57                            obj_name);
  58
  59                if (textconv_object(obj_context.path, obj_context.mode, sha1, 1, &buf, &size))
  60                        break;
  61
  62        case 'p':
  63                type = sha1_object_info(sha1, NULL);
  64                if (type < 0)
  65                        die("Not a valid object name %s", obj_name);
  66
  67                /* custom pretty-print here */
  68                if (type == OBJ_TREE) {
  69                        const char *ls_args[3] = { NULL };
  70                        ls_args[0] =  "ls-tree";
  71                        ls_args[1] =  obj_name;
  72                        return cmd_ls_tree(2, ls_args, NULL);
  73                }
  74
  75                if (type == OBJ_BLOB)
  76                        return stream_blob_to_fd(1, sha1, NULL, 0);
  77                buf = read_sha1_file(sha1, &type, &size);
  78                if (!buf)
  79                        die("Cannot read object %s", obj_name);
  80
  81                /* otherwise just spit out the data */
  82                break;
  83
  84        case 0:
  85                if (type_from_string(exp_type) == OBJ_BLOB) {
  86                        unsigned char blob_sha1[20];
  87                        if (sha1_object_info(sha1, NULL) == OBJ_TAG) {
  88                                char *buffer = read_sha1_file(sha1, &type, &size);
  89                                const char *target;
  90                                if (!skip_prefix(buffer, "object ", &target) ||
  91                                    get_sha1_hex(target, blob_sha1))
  92                                        die("%s not a valid tag", sha1_to_hex(sha1));
  93                                free(buffer);
  94                        } else
  95                                hashcpy(blob_sha1, sha1);
  96
  97                        if (sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
  98                                return stream_blob_to_fd(1, blob_sha1, NULL, 0);
  99                        /*
 100                         * we attempted to dereference a tag to a blob
 101                         * and failed; there may be new dereference
 102                         * mechanisms this code is not aware of.
 103                         * fall-back to the usual case.
 104                         */
 105                }
 106                buf = read_object_with_reference(sha1, exp_type, &size, NULL);
 107                break;
 108
 109        default:
 110                die("git cat-file: unknown option: %s", exp_type);
 111        }
 112
 113        if (!buf)
 114                die("git cat-file %s: bad file", obj_name);
 115
 116        write_or_die(1, buf, size);
 117        return 0;
 118}
 119
 120struct expand_data {
 121        unsigned char sha1[20];
 122        enum object_type type;
 123        unsigned long size;
 124        unsigned long disk_size;
 125        const char *rest;
 126        unsigned char delta_base_sha1[20];
 127
 128        /*
 129         * If mark_query is true, we do not expand anything, but rather
 130         * just mark the object_info with items we wish to query.
 131         */
 132        int mark_query;
 133
 134        /*
 135         * Whether to split the input on whitespace before feeding it to
 136         * get_sha1; this is decided during the mark_query phase based on
 137         * whether we have a %(rest) token in our format.
 138         */
 139        int split_on_whitespace;
 140
 141        /*
 142         * After a mark_query run, this object_info is set up to be
 143         * passed to sha1_object_info_extended. It will point to the data
 144         * elements above, so you can retrieve the response from there.
 145         */
 146        struct object_info info;
 147};
 148
 149static int is_atom(const char *atom, const char *s, int slen)
 150{
 151        int alen = strlen(atom);
 152        return alen == slen && !memcmp(atom, s, alen);
 153}
 154
 155static void expand_atom(struct strbuf *sb, const char *atom, int len,
 156                        void *vdata)
 157{
 158        struct expand_data *data = vdata;
 159
 160        if (is_atom("objectname", atom, len)) {
 161                if (!data->mark_query)
 162                        strbuf_addstr(sb, sha1_to_hex(data->sha1));
 163        } else if (is_atom("objecttype", atom, len)) {
 164                if (data->mark_query)
 165                        data->info.typep = &data->type;
 166                else
 167                        strbuf_addstr(sb, typename(data->type));
 168        } else if (is_atom("objectsize", atom, len)) {
 169                if (data->mark_query)
 170                        data->info.sizep = &data->size;
 171                else
 172                        strbuf_addf(sb, "%lu", data->size);
 173        } else if (is_atom("objectsize:disk", atom, len)) {
 174                if (data->mark_query)
 175                        data->info.disk_sizep = &data->disk_size;
 176                else
 177                        strbuf_addf(sb, "%lu", data->disk_size);
 178        } else if (is_atom("rest", atom, len)) {
 179                if (data->mark_query)
 180                        data->split_on_whitespace = 1;
 181                else if (data->rest)
 182                        strbuf_addstr(sb, data->rest);
 183        } else if (is_atom("deltabase", atom, len)) {
 184                if (data->mark_query)
 185                        data->info.delta_base_sha1 = data->delta_base_sha1;
 186                else
 187                        strbuf_addstr(sb, sha1_to_hex(data->delta_base_sha1));
 188        } else
 189                die("unknown format element: %.*s", len, atom);
 190}
 191
 192static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 193{
 194        const char *end;
 195
 196        if (*start != '(')
 197                return 0;
 198        end = strchr(start + 1, ')');
 199        if (!end)
 200                die("format element '%s' does not end in ')'", start);
 201
 202        expand_atom(sb, start + 1, end - start - 1, data);
 203
 204        return end - start + 1;
 205}
 206
 207static void print_object_or_die(int fd, struct expand_data *data)
 208{
 209        const unsigned char *sha1 = data->sha1;
 210
 211        assert(data->info.typep);
 212
 213        if (data->type == OBJ_BLOB) {
 214                if (stream_blob_to_fd(fd, sha1, NULL, 0) < 0)
 215                        die("unable to stream %s to stdout", sha1_to_hex(sha1));
 216        }
 217        else {
 218                enum object_type type;
 219                unsigned long size;
 220                void *contents;
 221
 222                contents = read_sha1_file(sha1, &type, &size);
 223                if (!contents)
 224                        die("object %s disappeared", sha1_to_hex(sha1));
 225                if (type != data->type)
 226                        die("object %s changed type!?", sha1_to_hex(sha1));
 227                if (data->info.sizep && size != data->size)
 228                        die("object %s changed size!?", sha1_to_hex(sha1));
 229
 230                write_or_die(fd, contents, size);
 231                free(contents);
 232        }
 233}
 234
 235struct batch_options {
 236        int enabled;
 237        int follow_symlinks;
 238        int print_contents;
 239        const char *format;
 240};
 241
 242static int batch_one_object(const char *obj_name, struct batch_options *opt,
 243                            struct expand_data *data)
 244{
 245        struct strbuf buf = STRBUF_INIT;
 246        struct object_context ctx;
 247        int flags = opt->follow_symlinks ? GET_SHA1_FOLLOW_SYMLINKS : 0;
 248        enum follow_symlinks_result result;
 249
 250        if (!obj_name)
 251           return 1;
 252
 253        result = get_sha1_with_context(obj_name, flags, data->sha1, &ctx);
 254        if (result != FOUND) {
 255                switch (result) {
 256                case MISSING_OBJECT:
 257                        printf("%s missing\n", obj_name);
 258                        break;
 259                case DANGLING_SYMLINK:
 260                        printf("dangling %"PRIuMAX"\n%s\n",
 261                               (uintmax_t)strlen(obj_name), obj_name);
 262                        break;
 263                case SYMLINK_LOOP:
 264                        printf("loop %"PRIuMAX"\n%s\n",
 265                               (uintmax_t)strlen(obj_name), obj_name);
 266                        break;
 267                case NOT_DIR:
 268                        printf("notdir %"PRIuMAX"\n%s\n",
 269                               (uintmax_t)strlen(obj_name), obj_name);
 270                        break;
 271                default:
 272                        die("BUG: unknown get_sha1_with_context result %d\n",
 273                               result);
 274                        break;
 275                }
 276                fflush(stdout);
 277                return 0;
 278        }
 279
 280        if (ctx.mode == 0) {
 281                printf("symlink %"PRIuMAX"\n%s\n",
 282                       (uintmax_t)ctx.symlink_path.len,
 283                       ctx.symlink_path.buf);
 284                fflush(stdout);
 285                return 0;
 286        }
 287
 288        if (sha1_object_info_extended(data->sha1, &data->info, LOOKUP_REPLACE_OBJECT) < 0) {
 289                printf("%s missing\n", obj_name);
 290                fflush(stdout);
 291                return 0;
 292        }
 293
 294        strbuf_expand(&buf, opt->format, expand_format, data);
 295        strbuf_addch(&buf, '\n');
 296        write_or_die(1, buf.buf, buf.len);
 297        strbuf_release(&buf);
 298
 299        if (opt->print_contents) {
 300                print_object_or_die(1, data);
 301                write_or_die(1, "\n", 1);
 302        }
 303        return 0;
 304}
 305
 306static int batch_objects(struct batch_options *opt)
 307{
 308        struct strbuf buf = STRBUF_INIT;
 309        struct expand_data data;
 310        int save_warning;
 311        int retval = 0;
 312
 313        if (!opt->format)
 314                opt->format = "%(objectname) %(objecttype) %(objectsize)";
 315
 316        /*
 317         * Expand once with our special mark_query flag, which will prime the
 318         * object_info to be handed to sha1_object_info_extended for each
 319         * object.
 320         */
 321        memset(&data, 0, sizeof(data));
 322        data.mark_query = 1;
 323        strbuf_expand(&buf, opt->format, expand_format, &data);
 324        data.mark_query = 0;
 325
 326        /*
 327         * If we are printing out the object, then always fill in the type,
 328         * since we will want to decide whether or not to stream.
 329         */
 330        if (opt->print_contents)
 331                data.info.typep = &data.type;
 332
 333        /*
 334         * We are going to call get_sha1 on a potentially very large number of
 335         * objects. In most large cases, these will be actual object sha1s. The
 336         * cost to double-check that each one is not also a ref (just so we can
 337         * warn) ends up dwarfing the actual cost of the object lookups
 338         * themselves. We can work around it by just turning off the warning.
 339         */
 340        save_warning = warn_on_object_refname_ambiguity;
 341        warn_on_object_refname_ambiguity = 0;
 342
 343        while (strbuf_getline(&buf, stdin, '\n') != EOF) {
 344                if (data.split_on_whitespace) {
 345                        /*
 346                         * Split at first whitespace, tying off the beginning
 347                         * of the string and saving the remainder (or NULL) in
 348                         * data.rest.
 349                         */
 350                        char *p = strpbrk(buf.buf, " \t");
 351                        if (p) {
 352                                while (*p && strchr(" \t", *p))
 353                                        *p++ = '\0';
 354                        }
 355                        data.rest = p;
 356                }
 357
 358                retval = batch_one_object(buf.buf, opt, &data);
 359                if (retval)
 360                        break;
 361        }
 362
 363        strbuf_release(&buf);
 364        warn_on_object_refname_ambiguity = save_warning;
 365        return retval;
 366}
 367
 368static const char * const cat_file_usage[] = {
 369        N_("git cat-file (-t [--allow-unknown-type]|-s [--allow-unknown-type]|-e|-p|<type>|--textconv) <object>"),
 370        N_("git cat-file (--batch | --batch-check) [--follow-symlinks] < <list-of-objects>"),
 371        NULL
 372};
 373
 374static int git_cat_file_config(const char *var, const char *value, void *cb)
 375{
 376        if (userdiff_config(var, value) < 0)
 377                return -1;
 378
 379        return git_default_config(var, value, cb);
 380}
 381
 382static int batch_option_callback(const struct option *opt,
 383                                 const char *arg,
 384                                 int unset)
 385{
 386        struct batch_options *bo = opt->value;
 387
 388        if (bo->enabled) {
 389                return 1;
 390        }
 391
 392        bo->enabled = 1;
 393        bo->print_contents = !strcmp(opt->long_name, "batch");
 394        bo->format = arg;
 395
 396        return 0;
 397}
 398
 399int cmd_cat_file(int argc, const char **argv, const char *prefix)
 400{
 401        int opt = 0;
 402        const char *exp_type = NULL, *obj_name = NULL;
 403        struct batch_options batch = {0};
 404        int unknown_type = 0;
 405
 406        const struct option options[] = {
 407                OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 408                OPT_CMDMODE('t', NULL, &opt, N_("show object type"), 't'),
 409                OPT_CMDMODE('s', NULL, &opt, N_("show object size"), 's'),
 410                OPT_CMDMODE('e', NULL, &opt,
 411                            N_("exit with zero when there's no error"), 'e'),
 412                OPT_CMDMODE('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 413                OPT_CMDMODE(0, "textconv", &opt,
 414                            N_("for blob objects, run textconv on object's content"), 'c'),
 415                OPT_BOOL( 0, "allow-unknown-type", &unknown_type,
 416                          N_("allow -s and -t to work with broken/corrupt objects")),
 417                { OPTION_CALLBACK, 0, "batch", &batch, "format",
 418                        N_("show info and content of objects fed from the standard input"),
 419                        PARSE_OPT_OPTARG, batch_option_callback },
 420                { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 421                        N_("show info about objects fed from the standard input"),
 422                        PARSE_OPT_OPTARG, batch_option_callback },
 423                OPT_BOOL(0, "follow-symlinks", &batch.follow_symlinks,
 424                         N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 425                OPT_END()
 426        };
 427
 428        git_config(git_cat_file_config, NULL);
 429
 430        argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 431
 432        if (opt) {
 433                if (argc == 1)
 434                        obj_name = argv[0];
 435                else
 436                        usage_with_options(cat_file_usage, options);
 437        }
 438        if (!opt && !batch.enabled) {
 439                if (argc == 2) {
 440                        exp_type = argv[0];
 441                        obj_name = argv[1];
 442                } else
 443                        usage_with_options(cat_file_usage, options);
 444        }
 445        if (batch.enabled && (opt || argc)) {
 446                usage_with_options(cat_file_usage, options);
 447        }
 448
 449        if (batch.follow_symlinks && !batch.enabled) {
 450                usage_with_options(cat_file_usage, options);
 451        }
 452
 453        if (batch.enabled)
 454                return batch_objects(&batch);
 455
 456        if (unknown_type && opt != 't' && opt != 's')
 457                die("git cat-file --allow-unknown-type: use with -s or -t");
 458        return cat_one_file(opt, exp_type, obj_name, unknown_type);
 459}