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 #define BATCH 1
  17 #define BATCH_CHECK 2
  18
  19 static int cat_one_file(int opt, const char *exp_type, const char *obj_name)
  20 {
  21         unsigned char sha1[20];
  22         enum object_type type;
  23         char *buf;
  24         unsigned long size;
  25         struct object_context obj_context;
  26
  27         if (get_sha1_with_context(obj_name, 0, sha1, &obj_context))
  28                 die("Not a valid object name %s", obj_name);
  29
  30         buf = NULL;
  31         switch (opt) {
  32         case 't':
  33                 type = sha1_object_info(sha1, NULL);
  34                 if (type > 0) {
  35                         printf("%s\n", typename(type));
  36                         return 0;
  37                 }
  38                 break;
  39
  40         case 's':
  41                 type = sha1_object_info(sha1, &size);
  42                 if (type > 0) {
  43                         printf("%lu\n", size);
  44                         return 0;
  45                 }
  46                 break;
  47
  48         case 'e':
  49                 return !has_sha1_file(sha1);
  50
  51         case 'p':
  52                 type = sha1_object_info(sha1, NULL);
  53                 if (type < 0)
  54                         die("Not a valid object name %s", obj_name);
  55
  56                 /* custom pretty-print here */
  57                 if (type == OBJ_TREE) {
  58                         const char *ls_args[3] = { NULL };
  59                         ls_args[0] =  "ls-tree";
  60                         ls_args[1] =  obj_name;
  61                         return cmd_ls_tree(2, ls_args, NULL);
  62                 }
  63
  64                 if (type == OBJ_BLOB)
  65                         return stream_blob_to_fd(1, sha1, NULL, 0);
  66                 buf = read_sha1_file(sha1, &type, &size);
  67                 if (!buf)
  68                         die("Cannot read object %s", obj_name);
  69
  70                 /* otherwise just spit out the data */
  71                 break;
  72
  73         case 'c':
  74                 if (!obj_context.path[0])
  75                         die("git cat-file --textconv %s: <object> must be <sha1:path>",
  76                             obj_name);
  77
  78                 if (!textconv_object(obj_context.path, obj_context.mode, sha1, 1, &buf, &size))
  79                         die("git cat-file --textconv: unable to run textconv on %s",
  80                             obj_name);
  81                 break;
  82
  83         case 0:
  84                 if (type_from_string(exp_type) == OBJ_BLOB) {
  85                         unsigned char blob_sha1[20];
  86                         if (sha1_object_info(sha1, NULL) == OBJ_TAG) {
  87                                 enum object_type type;
  88                                 unsigned long size;
  89                                 char *buffer = read_sha1_file(sha1, &type, &size);
  90                                 if (memcmp(buffer, "object ", 7) ||
  91                                     get_sha1_hex(buffer + 7, blob_sha1))
  92                                         die("%s not a valid tag", sha1_to_hex(sha1));
  93                                 free(buffer);
  94                         } else
  95                                 hashcpy(blob_sha1, sha1);
  96
  97                         if (sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
  98                                 return stream_blob_to_fd(1, blob_sha1, NULL, 0);
  99                         /*
 100                          * we attempted to dereference a tag to a blob
 101                          * and failed; there may be new dereference
 102                          * mechanisms this code is not aware of.
 103                          * fall-back to the usual case.
 104                          */
 105                 }
 106                 buf = read_object_with_reference(sha1, exp_type, &size, NULL);
 107                 break;
 108
 109         default:
 110                 die("git cat-file: unknown option: %s", exp_type);
 111         }
 112
 113         if (!buf)
 114                 die("git cat-file %s: bad file", obj_name);
 115
 116         write_or_die(1, buf, size);
 117         return 0;
 118 }
 119
 120 static void print_object_or_die(int fd, const unsigned char *sha1,
 121                                 enum object_type type, unsigned long size)
 122 {
 123         if (type == OBJ_BLOB) {
 124                 if (stream_blob_to_fd(fd, sha1, NULL, 0) < 0)
 125                         die("unable to stream %s to stdout", sha1_to_hex(sha1));
 126         }
 127         else {
 128                 enum object_type rtype;
 129                 unsigned long rsize;
 130                 void *contents;
 131
 132                 contents = read_sha1_file(sha1, &rtype, &rsize);
 133                 if (!contents)
 134                         die("object %s disappeared", sha1_to_hex(sha1));
 135                 if (rtype != type)
 136                         die("object %s changed type!?", sha1_to_hex(sha1));
 137                 if (rsize != size)
 138                         die("object %s change size!?", sha1_to_hex(sha1));
 139
 140                 write_or_die(fd, contents, size);
 141                 free(contents);
 142         }
 143 }
 144
 145 static int batch_one_object(const char *obj_name, int print_contents)
 146 {
 147         unsigned char sha1[20];
 148         enum object_type type = 0;
 149         unsigned long size;
 150
 151         if (!obj_name)
 152            return 1;
 153
 154         if (get_sha1(obj_name, sha1)) {
 155                 printf("%s missing\n", obj_name);
 156                 fflush(stdout);
 157                 return 0;
 158         }
 159
 160         type = sha1_object_info(sha1, &size);
 161         if (type <= 0) {
 162                 printf("%s missing\n", obj_name);
 163                 fflush(stdout);
 164                 return 0;
 165         }
 166
 167         printf("%s %s %lu\n", sha1_to_hex(sha1), typename(type), size);
 168         fflush(stdout);
 169
 170         if (print_contents == BATCH) {
 171                 print_object_or_die(1, sha1, type, size);
 172                 write_or_die(1, "\n", 1);
 173         }
 174         return 0;
 175 }
 176
 177 static int batch_objects(int print_contents)
 178 {
 179         struct strbuf buf = STRBUF_INIT;
 180
 181         while (strbuf_getline(&buf, stdin, '\n') != EOF) {
 182                 int error = batch_one_object(buf.buf, print_contents);
 183                 if (error)
 184                         return error;
 185         }
 186
 187         return 0;
 188 }
 189
 190 static const char * const cat_file_usage[] = {
 191         N_("git cat-file (-t|-s|-e|-p|<type>|--textconv) <object>"),
 192         N_("git cat-file (--batch|--batch-check) < <list_of_objects>"),
 193         NULL
 194 };
 195
 196 static int git_cat_file_config(const char *var, const char *value, void *cb)
 197 {
 198         if (userdiff_config(var, value) < 0)
 199                 return -1;
 200
 201         return git_default_config(var, value, cb);
 202 }
 203
 204 int cmd_cat_file(int argc, const char **argv, const char *prefix)
 205 {
 206         int opt = 0, batch = 0;
 207         const char *exp_type = NULL, *obj_name = NULL;
 208
 209         const struct option options[] = {
 210                 OPT_GROUP(N_("<type> can be one of: blob, tree, commit, tag")),
 211                 OPT_SET_INT('t', NULL, &opt, N_("show object type"), 't'),
 212                 OPT_SET_INT('s', NULL, &opt, N_("show object size"), 's'),
 213                 OPT_SET_INT('e', NULL, &opt,
 214                             N_("exit with zero when there's no error"), 'e'),
 215                 OPT_SET_INT('p', NULL, &opt, N_("pretty-print object's content"), 'p'),
 216                 OPT_SET_INT(0, "textconv", &opt,
 217                             N_("for blob objects, run textconv on object's content"), 'c'),
 218                 OPT_SET_INT(0, "batch", &batch,
 219                             N_("show info and content of objects fed from the standard input"),
 220                             BATCH),
 221                 OPT_SET_INT(0, "batch-check", &batch,
 222                             N_("show info about objects fed from the standard input"),
 223                             BATCH_CHECK),
 224                 OPT_END()
 225         };
 226
 227         git_config(git_cat_file_config, NULL);
 228
 229         if (argc != 3 && argc != 2)
 230                 usage_with_options(cat_file_usage, options);
 231
 232         argc = parse_options(argc, argv, prefix, options, cat_file_usage, 0);
 233
 234         if (opt) {
 235                 if (argc == 1)
 236                         obj_name = argv[0];
 237                 else
 238                         usage_with_options(cat_file_usage, options);
 239         }
 240         if (!opt && !batch) {
 241                 if (argc == 2) {
 242                         exp_type = argv[0];
 243                         obj_name = argv[1];
 244                 } else
 245                         usage_with_options(cat_file_usage, options);
 246         }
 247         if (batch && (opt || argc)) {
 248                 usage_with_options(cat_file_usage, options);
 249         }
 250
 251         if (batch)
 252                 return batch_objects(batch);
 253
 254         return cat_one_file(opt, exp_type, obj_name);
 255 }