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        const char *rest;
 123
 124        /*
 125         * If mark_query is true, we do not expand anything, but rather
 126         * just mark the object_info with items we wish to query.
 127         */
 128        int mark_query;
 129
 130        /*
 131         * After a mark_query run, this object_info is set up to be
 132         * passed to sha1_object_info_extended. It will point to the data
 133         * elements above, so you can retrieve the response from there.
 134         */
 135        struct object_info info;
 136};
 137
 138static int is_atom(const char *atom, const char *s, int slen)
 139{
 140        int alen = strlen(atom);
 141        return alen == slen && !memcmp(atom, s, alen);
 142}
 143
 144static void expand_atom(struct strbuf *sb, const char *atom, int len,
 145                        void *vdata)
 146{
 147        struct expand_data *data = vdata;
 148
 149        if (is_atom("objectname", atom, len)) {
 150                if (!data->mark_query)
 151                        strbuf_addstr(sb, sha1_to_hex(data->sha1));
 152        } else if (is_atom("objecttype", atom, len)) {
 153                if (!data->mark_query)
 154                        strbuf_addstr(sb, typename(data->type));
 155        } else if (is_atom("objectsize", atom, len)) {
 156                if (data->mark_query)
 157                        data->info.sizep = &data->size;
 158                else
 159                        strbuf_addf(sb, "%lu", data->size);
 160        } else if (is_atom("objectsize:disk", atom, len)) {
 161                if (data->mark_query)
 162                        data->info.disk_sizep = &data->disk_size;
 163                else
 164                        strbuf_addf(sb, "%lu", data->disk_size);
 165        } else if (is_atom("rest", atom, len)) {
 166                if (!data->mark_query && data->rest)
 167                        strbuf_addstr(sb, data->rest);
 168        } else
 169                die("unknown format element: %.*s", len, atom);
 170}
 171
 172static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 173{
 174        const char *end;
 175
 176        if (*start != '(')
 177                return 0;
 178        end = strchr(start + 1, ')');
 179        if (!end)
 180                die("format element '%s' does not end in ')'", start);
 181
 182        expand_atom(sb, start + 1, end - start - 1, data);
 183
 184        return end - start + 1;
 185}
 186
 187static void print_object_or_die(int fd, const unsigned char *sha1,
 188                                enum object_type type, unsigned long size)
 189{
 190        if (type == OBJ_BLOB) {
 191                if (stream_blob_to_fd(fd, sha1, NULL, 0) < 0)
 192                        die("unable to stream %s to stdout", sha1_to_hex(sha1));
 193        }
 194        else {
 195                enum object_type rtype;
 196                unsigned long rsize;
 197                void *contents;
 198
 199                contents = read_sha1_file(sha1, &rtype, &rsize);
 200                if (!contents)
 201                        die("object %s disappeared", sha1_to_hex(sha1));
 202                if (rtype != type)
 203                        die("object %s changed type!?", sha1_to_hex(sha1));
 204                if (rsize != size)
 205                        die("object %s change size!?", sha1_to_hex(sha1));
 206
 207                write_or_die(fd, contents, size);
 208                free(contents);
 209        }
 210}
 211
 212struct batch_options {
 213        int enabled;
 214        int print_contents;
 215        const char *format;
 216};
 217
 218static int batch_one_object(const char *obj_name, struct batch_options *opt,
 219                            struct expand_data *data)
 220{
 221        struct strbuf buf = STRBUF_INIT;
 222
 223        if (!obj_name)
 224           return 1;
 225
 226        if (get_sha1(obj_name, data->sha1)) {
 227                printf("%s missing\n", obj_name);
 228                fflush(stdout);
 229                return 0;
 230        }
 231
 232        data->type = sha1_object_info_extended(data->sha1, &data->info);
 233        if (data->type <= 0) {
 234                printf("%s missing\n", obj_name);
 235                fflush(stdout);
 236                return 0;
 237        }
 238
 239        strbuf_expand(&buf, opt->format, expand_format, data);
 240        strbuf_addch(&buf, '\n');
 241        write_or_die(1, buf.buf, buf.len);
 242        strbuf_release(&buf);
 243
 244        if (opt->print_contents) {
 245                print_object_or_die(1, data->sha1, data->type, data->size);
 246                write_or_die(1, "\n", 1);
 247        }
 248        return 0;
 249}
 250
 251static int batch_objects(struct batch_options *opt)
 252{
 253        struct strbuf buf = STRBUF_INIT;
 254        struct expand_data data;
 255
 256        if (!opt->format)
 257                opt->format = "%(objectname) %(objecttype) %(objectsize)";
 258
 259        /*
 260         * Expand once with our special mark_query flag, which will prime the
 261         * object_info to be handed to sha1_object_info_extended for each
 262         * object.
 263         */
 264        memset(&data, 0, sizeof(data));
 265        data.mark_query = 1;
 266        strbuf_expand(&buf, opt->format, expand_format, &data);
 267        data.mark_query = 0;
 268
 269        /*
 270         * We are going to call get_sha1 on a potentially very large number of
 271         * objects. In most large cases, these will be actual object sha1s. The
 272         * cost to double-check that each one is not also a ref (just so we can
 273         * warn) ends up dwarfing the actual cost of the object lookups
 274         * themselves. We can work around it by just turning off the warning.
 275         */
 276        warn_on_object_refname_ambiguity = 0;
 277
 278        while (strbuf_getline(&buf, stdin, '\n') != EOF) {
 279                char *p;
 280                int error;
 281
 282                /*
 283                 * Split at first whitespace, tying off the beginning of the
 284                 * string and saving the remainder (or NULL) in data.rest.
 285                 */
 286                p = strpbrk(buf.buf, " \t");
 287                if (p) {
 288                        while (*p && strchr(" \t", *p))
 289                                *p++ = '\0';
 290                }
 291                data.rest = p;
 292
 293                error = batch_one_object(buf.buf, opt, &data);
 294                if (error)
 295                        return error;
 296        }
 297
 298        return 0;
 299}
 300
 301static const char * const cat_file_usage[] = {
 302        N_("git cat-file (-t|-s|-e|-p|<type>|--textconv) <object>"),
 303        N_("git cat-file (--batch|--batch-check) < <list_of_objects>"),
 304        NULL
 305};
 306
 307static int git_cat_file_config(const char *var, const char *value, void *cb)
 308{
 309        if (userdiff_config(var, value) < 0)
 310                return -1;
 311
 312        return git_default_config(var, value, cb);
 313}
 314
 315static int batch_option_callback(const struct option *opt,
 316                                 const char *arg,
 317                                 int unset)
 318{
 319        struct batch_options *bo = opt->value;
 320
 321        if (unset) {
 322                memset(bo, 0, sizeof(*bo));
 323                return 0;
 324        }
 325
 326        bo->enabled = 1;
 327        bo->print_contents = !strcmp(opt->long_name, "batch");
 328        bo->format = arg;
 329
 330        return 0;
 331}
 332
 333int cmd_cat_file(int argc, const char **argv, const char *prefix)
 334{
 335        int opt = 0;
 336        const char *exp_type = NULL, *obj_name = NULL;
 337        struct batch_options batch = {0};
 338
 339        const struct option options[] = {
 340                OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 341                OPT_SET_INT('t', NULL, &opt, N_("show object type"), 't'),
 342                OPT_SET_INT('s', NULL, &opt, N_("show object size"), 's'),
 343                OPT_SET_INT('e', NULL, &opt,
 344                            N_("exit with zero when there's no error"), 'e'),
 345                OPT_SET_INT('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 346                OPT_SET_INT(0, "textconv", &opt,
 347                            N_("for blob objects, run textconv on object's content"), 'c'),
 348                { OPTION_CALLBACK, 0, "batch", &batch, "format",
 349                        N_("show info and content of objects fed from the standard input"),
 350                        PARSE_OPT_OPTARG, batch_option_callback },
 351                { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 352                        N_("show info about objects fed from the standard input"),
 353                        PARSE_OPT_OPTARG, batch_option_callback },
 354                OPT_END()
 355        };
 356
 357        git_config(git_cat_file_config, NULL);
 358
 359        if (argc != 3 && argc != 2)
 360                usage_with_options(cat_file_usage, options);
 361
 362        argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 363
 364        if (opt) {
 365                if (argc == 1)
 366                        obj_name = argv[0];
 367                else
 368                        usage_with_options(cat_file_usage, options);
 369        }
 370        if (!opt && !batch.enabled) {
 371                if (argc == 2) {
 372                        exp_type = argv[0];
 373                        obj_name = argv[1];
 374                } else
 375                        usage_with_options(cat_file_usage, options);
 376        }
 377        if (batch.enabled && (opt || argc)) {
 378                usage_with_options(cat_file_usage, options);
 379        }
 380
 381        if (batch.enabled)
 382                return batch_objects(&batch);
 383
 384        return cat_one_file(opt, exp_type, obj_name);
 385}