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 "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
  16 static 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
 117 static void print_object_or_die(int fd, const unsigned char *sha1,
 118                                 enum object_type type, unsigned long size)
 119 {
 120         if (type == OBJ_BLOB) {
 121                 if (stream_blob_to_fd(fd, sha1, NULL, 0) < 0)
 122                         die("unable to stream %s to stdout", sha1_to_hex(sha1));
 123         }
 124         else {
 125                 enum object_type rtype;
 126                 unsigned long rsize;
 127                 void *contents;
 128
 129                 contents = read_sha1_file(sha1, &rtype, &rsize);
 130                 if (!contents)
 131                         die("object %s disappeared", sha1_to_hex(sha1));
 132                 if (rtype != type)
 133                         die("object %s changed type!?", sha1_to_hex(sha1));
 134                 if (rsize != size)
 135                         die("object %s change size!?", sha1_to_hex(sha1));
 136
 137                 write_or_die(fd, contents, size);
 138                 free(contents);
 139         }
 140 }
 141
 142 struct batch_options {
 143         int enabled;
 144         int print_contents;
 145 };
 146
 147 static int batch_one_object(const char *obj_name, struct batch_options *opt)
 148 {
 149         unsigned char sha1[20];
 150         enum object_type type = 0;
 151         unsigned long size;
 152
 153         if (!obj_name)
 154            return 1;
 155
 156         if (get_sha1(obj_name, sha1)) {
 157                 printf("%s missing\n", obj_name);
 158                 fflush(stdout);
 159                 return 0;
 160         }
 161
 162         type = sha1_object_info(sha1, &size);
 163         if (type <= 0) {
 164                 printf("%s missing\n", obj_name);
 165                 fflush(stdout);
 166                 return 0;
 167         }
 168
 169         printf("%s %s %lu\n", sha1_to_hex(sha1), typename(type), size);
 170         fflush(stdout);
 171
 172         if (opt->print_contents) {
 173                 print_object_or_die(1, sha1, type, size);
 174                 write_or_die(1, "\n", 1);
 175         }
 176         return 0;
 177 }
 178
 179 static int batch_objects(struct batch_options *opt)
 180 {
 181         struct strbuf buf = STRBUF_INIT;
 182
 183         while (strbuf_getline(&buf, stdin, '\n') != EOF) {
 184                 int error = batch_one_object(buf.buf, opt);
 185                 if (error)
 186                         return error;
 187         }
 188
 189         return 0;
 190 }
 191
 192 static const char * const cat_file_usage[] = {
 193         N_("git cat-file (-t|-s|-e|-p|<type>|--textconv) <object>"),
 194         N_("git cat-file (--batch|--batch-check) < <list_of_objects>"),
 195         NULL
 196 };
 197
 198 static int git_cat_file_config(const char *var, const char *value, void *cb)
 199 {
 200         if (userdiff_config(var, value) < 0)
 201                 return -1;
 202
 203         return git_default_config(var, value, cb);
 204 }
 205
 206 static int batch_option_callback(const struct option *opt,
 207                                  const char *arg,
 208                                  int unset)
 209 {
 210         struct batch_options *bo = opt->value;
 211
 212         if (unset) {
 213                 memset(bo, 0, sizeof(*bo));
 214                 return 0;
 215         }
 216
 217         bo->enabled = 1;
 218         bo->print_contents = !strcmp(opt->long_name, "batch");
 219
 220         return 0;
 221 }
 222
 223 int cmd_cat_file(int argc, const char **argv, const char *prefix)
 224 {
 225         int opt = 0;
 226         const char *exp_type = NULL, *obj_name = NULL;
 227         struct batch_options batch = {0};
 228
 229         const struct option options[] = {
 230                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 231                 OPT_SET_INT('t', NULL, &opt, N_("show object type"), 't'),
 232                 OPT_SET_INT('s', NULL, &opt, N_("show object size"), 's'),
 233                 OPT_SET_INT('e', NULL, &opt,
 234                             N_("exit with zero when there's no error"), 'e'),
 235                 OPT_SET_INT('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 236                 OPT_SET_INT(0, "textconv", &opt,
 237                             N_("for blob objects, run textconv on object's content"), 'c'),
 238                 { OPTION_CALLBACK, 0, "batch", &batch, NULL,
 239                         N_("show info and content of objects fed from the standard input"),
 240                         PARSE_OPT_NOARG, batch_option_callback },
 241                 { OPTION_CALLBACK, 0, "batch-check", &batch, NULL,
 242                         N_("show info about objects fed from the standard input"),
 243                         PARSE_OPT_NOARG, batch_option_callback },
 244                 OPT_END()
 245         };
 246
 247         git_config(git_cat_file_config, NULL);
 248
 249         if (argc != 3 && argc != 2)
 250                 usage_with_options(cat_file_usage, options);
 251
 252         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 253
 254         if (opt) {
 255                 if (argc == 1)
 256                         obj_name = argv[0];
 257                 else
 258                         usage_with_options(cat_file_usage, options);
 259         }
 260         if (!opt && !batch.enabled) {
 261                 if (argc == 2) {
 262                         exp_type = argv[0];
 263                         obj_name = argv[1];
 264                 } else
 265                         usage_with_options(cat_file_usage, options);
 266         }
 267         if (batch.enabled && (opt || argc)) {
 268                 usage_with_options(cat_file_usage, options);
 269         }
 270
 271         if (batch.enabled)
 272                 return batch_objects(&batch);
 273
 274         return cat_one_file(opt, exp_type, obj_name);
 275 }