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
 122        /*
 123         * If mark_query is true, we do not expand anything, but rather
 124         * just mark the object_info with items we wish to query.
 125         */
 126        int mark_query;
 127
 128        /*
 129         * After a mark_query run, this object_info is set up to be
 130         * passed to sha1_object_info_extended. It will point to the data
 131         * elements above, so you can retrieve the response from there.
 132         */
 133        struct object_info info;
 134};
 135
 136static int is_atom(const char *atom, const char *s, int slen)
 137{
 138        int alen = strlen(atom);
 139        return alen == slen && !memcmp(atom, s, alen);
 140}
 141
 142static void expand_atom(struct strbuf *sb, const char *atom, int len,
 143                        void *vdata)
 144{
 145        struct expand_data *data = vdata;
 146
 147        if (is_atom("objectname", atom, len)) {
 148                if (!data->mark_query)
 149                        strbuf_addstr(sb, sha1_to_hex(data->sha1));
 150        } else if (is_atom("objecttype", atom, len)) {
 151                if (!data->mark_query)
 152                        strbuf_addstr(sb, typename(data->type));
 153        } else if (is_atom("objectsize", atom, len)) {
 154                if (data->mark_query)
 155                        data->info.sizep = &data->size;
 156                else
 157                        strbuf_addf(sb, "%lu", data->size);
 158        } else
 159                die("unknown format element: %.*s", len, atom);
 160}
 161
 162static size_t expand_format(struct strbuf *sb, const char *start, void *data)
 163{
 164        const char *end;
 165
 166        if (*start != '(')
 167                return 0;
 168        end = strchr(start + 1, ')');
 169        if (!end)
 170                die("format element '%s' does not end in ')'", start);
 171
 172        expand_atom(sb, start + 1, end - start - 1, data);
 173
 174        return end - start + 1;
 175}
 176
 177static void print_object_or_die(int fd, const unsigned char *sha1,
 178                                enum object_type type, unsigned long size)
 179{
 180        if (type == OBJ_BLOB) {
 181                if (stream_blob_to_fd(fd, sha1, NULL, 0) < 0)
 182                        die("unable to stream %s to stdout", sha1_to_hex(sha1));
 183        }
 184        else {
 185                enum object_type rtype;
 186                unsigned long rsize;
 187                void *contents;
 188
 189                contents = read_sha1_file(sha1, &rtype, &rsize);
 190                if (!contents)
 191                        die("object %s disappeared", sha1_to_hex(sha1));
 192                if (rtype != type)
 193                        die("object %s changed type!?", sha1_to_hex(sha1));
 194                if (rsize != size)
 195                        die("object %s change size!?", sha1_to_hex(sha1));
 196
 197                write_or_die(fd, contents, size);
 198                free(contents);
 199        }
 200}
 201
 202struct batch_options {
 203        int enabled;
 204        int print_contents;
 205        const char *format;
 206};
 207
 208static int batch_one_object(const char *obj_name, struct batch_options *opt,
 209                            struct expand_data *data)
 210{
 211        struct strbuf buf = STRBUF_INIT;
 212
 213        if (!obj_name)
 214           return 1;
 215
 216        if (get_sha1(obj_name, data->sha1)) {
 217                printf("%s missing\n", obj_name);
 218                fflush(stdout);
 219                return 0;
 220        }
 221
 222        data->type = sha1_object_info_extended(data->sha1, &data->info);
 223        if (data->type <= 0) {
 224                printf("%s missing\n", obj_name);
 225                fflush(stdout);
 226                return 0;
 227        }
 228
 229        strbuf_expand(&buf, opt->format, expand_format, data);
 230        strbuf_addch(&buf, '\n');
 231        write_or_die(1, buf.buf, buf.len);
 232        strbuf_release(&buf);
 233
 234        if (opt->print_contents) {
 235                print_object_or_die(1, data->sha1, data->type, data->size);
 236                write_or_die(1, "\n", 1);
 237        }
 238        return 0;
 239}
 240
 241static int batch_objects(struct batch_options *opt)
 242{
 243        struct strbuf buf = STRBUF_INIT;
 244        struct expand_data data;
 245
 246        if (!opt->format)
 247                opt->format = "%(objectname) %(objecttype) %(objectsize)";
 248
 249        /*
 250         * Expand once with our special mark_query flag, which will prime the
 251         * object_info to be handed to sha1_object_info_extended for each
 252         * object.
 253         */
 254        memset(&data, 0, sizeof(data));
 255        data.mark_query = 1;
 256        strbuf_expand(&buf, opt->format, expand_format, &data);
 257        data.mark_query = 0;
 258
 259        while (strbuf_getline(&buf, stdin, '\n') != EOF) {
 260                int error = batch_one_object(buf.buf, opt, &data);
 261                if (error)
 262                        return error;
 263        }
 264
 265        return 0;
 266}
 267
 268static const char * const cat_file_usage[] = {
 269        N_("git cat-file (-t|-s|-e|-p|<type>|--textconv) <object>"),
 270        N_("git cat-file (--batch|--batch-check) < <list_of_objects>"),
 271        NULL
 272};
 273
 274static int git_cat_file_config(const char *var, const char *value, void *cb)
 275{
 276        if (userdiff_config(var, value) < 0)
 277                return -1;
 278
 279        return git_default_config(var, value, cb);
 280}
 281
 282static int batch_option_callback(const struct option *opt,
 283                                 const char *arg,
 284                                 int unset)
 285{
 286        struct batch_options *bo = opt->value;
 287
 288        if (unset) {
 289                memset(bo, 0, sizeof(*bo));
 290                return 0;
 291        }
 292
 293        bo->enabled = 1;
 294        bo->print_contents = !strcmp(opt->long_name, "batch");
 295        bo->format = arg;
 296
 297        return 0;
 298}
 299
 300int cmd_cat_file(int argc, const char **argv, const char *prefix)
 301{
 302        int opt = 0;
 303        const char *exp_type = NULL, *obj_name = NULL;
 304        struct batch_options batch = {0};
 305
 306        const struct option options[] = {
 307                OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 308                OPT_SET_INT('t', NULL, &opt, N_("show object type"), 't'),
 309                OPT_SET_INT('s', NULL, &opt, N_("show object size"), 's'),
 310                OPT_SET_INT('e', NULL, &opt,
 311                            N_("exit with zero when there's no error"), 'e'),
 312                OPT_SET_INT('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 313                OPT_SET_INT(0, "textconv", &opt,
 314                            N_("for blob objects, run textconv on object's content"), 'c'),
 315                { OPTION_CALLBACK, 0, "batch", &batch, "format",
 316                        N_("show info and content of objects fed from the standard input"),
 317                        PARSE_OPT_OPTARG, batch_option_callback },
 318                { OPTION_CALLBACK, 0, "batch-check", &batch, "format",
 319                        N_("show info about objects fed from the standard input"),
 320                        PARSE_OPT_OPTARG, batch_option_callback },
 321                OPT_END()
 322        };
 323
 324        git_config(git_cat_file_config, NULL);
 325
 326        if (argc != 3 && argc != 2)
 327                usage_with_options(cat_file_usage, options);
 328
 329        argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 330
 331        if (opt) {
 332                if (argc == 1)
 333                        obj_name = argv[0];
 334                else
 335                        usage_with_options(cat_file_usage, options);
 336        }
 337        if (!opt && !batch.enabled) {
 338                if (argc == 2) {
 339                        exp_type = argv[0];
 340                        obj_name = argv[1];
 341                } else
 342                        usage_with_options(cat_file_usage, options);
 343        }
 344        if (batch.enabled && (opt || argc)) {
 345                usage_with_options(cat_file_usage, options);
 346        }
 347
 348        if (batch.enabled)
 349                return batch_objects(&batch);
 350
 351        return cat_one_file(opt, exp_type, obj_name);
 352}