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 struct 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
 136 static 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
 142 static 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
 162 static 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
 177 static 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
 202 struct batch_options {
 203         int enabled;
 204         int print_contents;
 205         const char *format;
 206 };
 207
 208 static 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
 241 static 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
 268 static 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
 274 static 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
 282 static 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
 300 int 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 }