Andrew's git - gitweb.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 "exec_cmd.h"
   8#include "tag.h"
   9#include "tree.h"
  10#include "builtin.h"
  11#include "parse-options.h"
  12#include "diff.h"
  13#include "userdiff.h"
  14#include "streaming.h"
  15
  16static int cat_one_file(int opt, const char *exp_type, const char *obj_name)
  17{
  18        unsigned char sha1[20];
  19        enum object_type type;
  20        char *buf;
  21        unsigned long size;
  22        struct object_context obj_context;
  23
  24        if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
  25                die("Not a valid object name %s", obj_name);
  26
  27        buf = NULL;
  28        switch (opt) {
  29        case 't':
  30                type = sha1_object_info(sha1, NULL);
  31                if (type > 0) {
  32                        printf("%s\n", typename(type));
  33                        return 0;
  34                }
  35                break;
  36
  37        case 's':
  38                type = sha1_object_info(sha1, &size);
  39                if (type > 0) {
  40                        printf("%lu\n", size);
  41                        return 0;
  42                }
  43                break;
  44
  45        case 'e':
  46                return !has_sha1_file(sha1);
  47
  48        case 'p':
  49                type = sha1_object_info(sha1, NULL);
  50                if (type < 0)
  51                        die("Not a valid object name %s", obj_name);
  52
  53                /* custom pretty-print here */
  54                if (type == OBJ_TREE) {
  55                        const char *ls_args[3] = { NULL };
  56                        ls_args[0] =  "ls-tree";
  57                        ls_args[1] =  obj_name;
  58                        return cmd_ls_tree(2, ls_args, NULL);
  59                }
  60
  61                if (type == OBJ_BLOB)
  62                        return stream_blob_to_fd(1, sha1, NULL, 0);
  63                buf = read_sha1_file(sha1, &type, &size);
  64                if (!buf)
  65                        die("Cannot read object %s", obj_name);
  66
  67                /* otherwise just spit out the data */
  68                break;
  69
  70        case 'c':
  71                if (!obj_context.path[0])
  72                        die("git cat-file --textconv %s: <object> must be <sha1:path>",
  73                            obj_name);
  74
  75                if (!textconv_object(obj_context.path, obj_context.mode, sha1, 1, &buf, &size))
  76                        die("git cat-file --textconv: unable to run textconv on %s",
  77                            obj_name);
  78                break;
  79
  80        case 0:
  81                if (type_from_string(exp_type) == OBJ_BLOB) {
  82                        unsigned char blob_sha1[20];
  83                        if (sha1_object_info(sha1, NULL) == OBJ_TAG) {
  84                                enum object_type type;
  85                                unsigned long size;
  86                                char *buffer = read_sha1_file(sha1, &type, &size);
  87                                if (memcmp(buffer, "object ", 7) ||
  88                                    get_sha1_hex(buffer + 7, blob_sha1))
  89                                        die("%s not a valid tag", sha1_to_hex(sha1));
  90                                free(buffer);
  91                        } else
  92                                hashcpy(blob_sha1, sha1);
  93
  94                        if (sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
  95                                return stream_blob_to_fd(1, blob_sha1, NULL, 0);
  96                        /*
  97                         * we attempted to dereference a tag to a blob
  98                         * and failed; there may be new dereference
  99                         * mechanisms this code is not aware of.
 100                         * fall-back to the usual case.
 101                         */
 102                }
 103                buf = read_object_with_reference(sha1, exp_type, &size, NULL);
 104                break;
 105
 106        default:
 107                die("git cat-file: unknown option: %s", exp_type);
 108        }
 109
 110        if (!buf)
 111                die("git cat-file %s: bad file", obj_name);
 112
 113        write_or_die(1, buf, size);
 114        return 0;
 115}
 116
 117struct expand_data {
 118        unsigned char sha1[20];
 119        enum object_type type;
 120        unsigned long size;
 121        unsigned long disk_size;
 122
 123        /*
 124         * If mark_query is true, we do not expand anything, but rather
 125         * just mark the object_info with items we wish to query.
 126         */
 127        int mark_query;
 128
 129        /*
 130         * After a mark_query run, this object_info is set up to be
 131         * passed to sha1_object_info_extended. It will point to the data
 132         * elements above, so you can retrieve the response from there.
 133         */
 134        struct object_info info;
 135};
 136
 137static int is_atom(const char *atom, const char *s, int slen)
 138{
 139        int alen = strlen(atom);
 140        return alen == slen && !memcmp(atom, s, alen);
 141}
 142
 143static void expand_atom(struct strbuf *sb, const char *atom, int len,
 144                        void *vdata)
 145{
 146        struct expand_data *data = vdata;
 147
 148        if (is_atom("objectname", atom, len)) {
 149                if (!data->mark_query)
 150                        strbuf_addstr(sb, sha1_to_hex(data->sha1));
 151        } else if (is_atom("objecttype", atom, len)) {
 152                if (data->mark_query)
 153                        data->info.typep = &data->type;
 154                else
 155                        strbuf_addstr(sb, typename(data->type));
 156        } else if (is_atom("objectsize", atom, len)) {
 157                if (data->mark_query)
 158                        data->info.sizep = &data->size;
 159                else
 160                        strbuf_addf(sb, "%lu", data->size);
 161        } else if (is_atom("objectsize:disk", atom, len)) {
 162                if (data->mark_query)
 163                        data->info.disk_sizep = &data->disk_size;
 164                else
 165                        strbuf_addf(sb, "%lu", data->disk_size);
 166        } else
 167                die("unknown format element: %.*s", len, atom);
 168}
 169
 170static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 171{
 172        const char *end;
 173
 174        if (*start != '(')
 175                return 0;
 176        end = strchr(start + 1, ')');
 177        if (!end)
 178                die("format element '%s' does not end in ')'", start);
 179
 180        expand_atom(sb, start + 1, end - start - 1, data);
 181
 182        return end - start + 1;
 183}
 184
 185static void print_object_or_die(int fd, const unsigned char *sha1,
 186                                enum object_type type, unsigned long size)
 187{
 188        if (type == OBJ_BLOB) {
 189                if (stream_blob_to_fd(fd, sha1, NULL, 0) < 0)
 190                        die("unable to stream %s to stdout", sha1_to_hex(sha1));
 191        }
 192        else {
 193                enum object_type rtype;
 194                unsigned long rsize;
 195                void *contents;
 196
 197                contents = read_sha1_file(sha1, &rtype, &rsize);
 198                if (!contents)
 199                        die("object %s disappeared", sha1_to_hex(sha1));
 200                if (rtype != type)
 201                        die("object %s changed type!?", sha1_to_hex(sha1));
 202                if (rsize != size)
 203                        die("object %s change size!?", sha1_to_hex(sha1));
 204
 205                write_or_die(fd, contents, size);
 206                free(contents);
 207        }
 208}
 209
 210struct batch_options {
 211        int enabled;
 212        int print_contents;
 213        const char *format;
 214};
 215
 216static int batch_one_object(const char *obj_name, struct batch_options *opt,
 217                            struct expand_data *data)
 218{
 219        struct strbuf buf = STRBUF_INIT;
 220
 221        if (!obj_name)
 222           return 1;
 223
 224        if (get_sha1(obj_name, data->sha1)) {
 225                printf("%s missing\n", obj_name);
 226                fflush(stdout);
 227                return 0;
 228        }
 229
 230        if (sha1_object_info_extended(data->sha1, &data->info) < 0) {
 231                printf("%s missing\n", obj_name);
 232                fflush(stdout);
 233                return 0;
 234        }
 235
 236        strbuf_expand(&buf, opt->format, expand_format, data);
 237        strbuf_addch(&buf, '\n');
 238        write_or_die(1, buf.buf, buf.len);
 239        strbuf_release(&buf);
 240
 241        if (opt->print_contents) {
 242                print_object_or_die(1, data->sha1, data->type, data->size);
 243                write_or_die(1, "\n", 1);
 244        }
 245        return 0;
 246}
 247
 248static int batch_objects(struct batch_options *opt)
 249{
 250        struct strbuf buf = STRBUF_INIT;
 251        struct expand_data data;
 252
 253        if (!opt->format)
 254                opt->format = "%(objectname) %(objecttype) %(objectsize)";
 255
 256        /*
 257         * Expand once with our special mark_query flag, which will prime the
 258         * object_info to be handed to sha1_object_info_extended for each
 259         * object.
 260         */
 261        memset(&data, 0, sizeof(data));
 262        data.mark_query = 1;
 263        strbuf_expand(&buf, opt->format, expand_format, &data);
 264        data.mark_query = 0;
 265
 266        /*
 267         * We are going to call get_sha1 on a potentially very large number of
 268         * objects. In most large cases, these will be actual object sha1s. The
 269         * cost to double-check that each one is not also a ref (just so we can
 270         * warn) ends up dwarfing the actual cost of the object lookups
 271         * themselves. We can work around it by just turning off the warning.
 272         */
 273        warn_on_object_refname_ambiguity = 0;
 274
 275        while (strbuf_getline(&buf, stdin, '\n') != EOF) {
 276                int error = batch_one_object(buf.buf, opt, &data);
 277                if (error)
 278                        return error;
 279        }
 280
 281        return 0;
 282}
 283
 284static const char * const cat_file_usage[] = {
 285        N_("git cat-file (-t|-s|-e|-p|<type>|--textconv) <object>"),
 286        N_("git cat-file (--batch|--batch-check) < <list_of_objects>"),
 287        NULL
 288};
 289
 290static int git_cat_file_config(const char *var, const char *value, void *cb)
 291{
 292        if (userdiff_config(var, value) < 0)
 293                return -1;
 294
 295        return git_default_config(var, value, cb);
 296}
 297
 298static int batch_option_callback(const struct option *opt,
 299                                 const char *arg,
 300                                 int unset)
 301{
 302        struct batch_options *bo = opt->value;
 303
 304        if (unset) {
 305                memset(bo, 0, sizeof(*bo));
 306                return 0;
 307        }
 308
 309        bo->enabled = 1;
 310        bo->print_contents = !strcmp(opt->long_name, "batch");
 311        bo->format = arg;
 312
 313        return 0;
 314}
 315
 316int cmd_cat_file(int argc, const char **argv, const char *prefix)
 317{
 318        int opt = 0;
 319        const char *exp_type = NULL, *obj_name = NULL;
 320        struct batch_options batch = {0};
 321
 322        const struct option options[] = {
 323                OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 324                OPT_SET_INT('t', NULL, &opt, N_("show object type"), 't'),
 325                OPT_SET_INT('s', NULL, &opt, N_("show object size"), 's'),
 326                OPT_SET_INT('e', NULL, &opt,
 327                            N_("exit with zero when there's no error"), 'e'),
 328                OPT_SET_INT('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 329                OPT_SET_INT(0, "textconv", &opt,
 330                            N_("for blob objects, run textconv on object's content"), 'c'),
 331                { OPTION_CALLBACK, 0, "batch", &batch, "format",
 332                        N_("show info and content of objects fed from the standard input"),
 333                        PARSE_OPT_OPTARG, batch_option_callback },
 334                { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 335                        N_("show info about objects fed from the standard input"),
 336                        PARSE_OPT_OPTARG, batch_option_callback },
 337                OPT_END()
 338        };
 339
 340        git_config(git_cat_file_config, NULL);
 341
 342        if (argc != 3 && argc != 2)
 343                usage_with_options(cat_file_usage, options);
 344
 345        argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 346
 347        if (opt) {
 348                if (argc == 1)
 349                        obj_name = argv[0];
 350                else
 351                        usage_with_options(cat_file_usage, options);
 352        }
 353        if (!opt && !batch.enabled) {
 354                if (argc == 2) {
 355                        exp_type = argv[0];
 356                        obj_name = argv[1];
 357                } else
 358                        usage_with_options(cat_file_usage, options);
 359        }
 360        if (batch.enabled && (opt || argc)) {
 361                usage_with_options(cat_file_usage, options);
 362        }
 363
 364        if (batch.enabled)
 365                return batch_objects(&batch);
 366
 367        return cat_one_file(opt, exp_type, obj_name);
 368}