Documentation/git-cat-file.txt

   1 git-cat-file(1)
   2 ===============
   3
   4 NAME
   5 ----
   6 git-cat-file - Provide content or type and size information for repository objects
   7
   8
   9 SYNOPSIS
  10 --------
  11 [verse]
  12 'git cat-file' (-t [--allow-unknown-type]| -s [--allow-unknown-type]| -e | -p | <type> | --textconv | --filters ) [--path=<path>] <object>
  13 'git cat-file' (--batch | --batch-check) [ --textconv | --filters ] [--follow-symlinks]
  14
  15 DESCRIPTION
  16 -----------
  17 In its first form, the command provides the content or the type of an object in
  18 the repository. The type is required unless `-t` or `-p` is used to find the
  19 object type, or `-s` is used to find the object size, or `--textconv` or
  20 `--filters` is used (which imply type "blob").
  21
  22 In the second form, a list of objects (separated by linefeeds) is provided on
  23 stdin, and the SHA-1, type, and size of each object is printed on stdout. The
  24 output format can be overridden using the optional `<format>` argument. If
  25 either `--textconv` or `--filters` was specified, the input is expected to
  26 list the object names followed by the path name, separated by a single white
  27 space, so that the appropriate drivers can be determined.
  28
  29 OPTIONS
  30 -------
  31 <object>::
  32         The name of the object to show.
  33         For a more complete list of ways to spell object names, see
  34         the "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
  35
  36 -t::
  37         Instead of the content, show the object type identified by
  38         <object>.
  39
  40 -s::
  41         Instead of the content, show the object size identified by
  42         <object>.
  43
  44 -e::
  45         Exit with zero status if <object> exists and is a valid
  46         object. If <object> is of an invalid format exit with non-zero and
  47         emits an error on stderr.
  48
  49 -p::
  50         Pretty-print the contents of <object> based on its type.
  51
  52 <type>::
  53         Typically this matches the real type of <object> but asking
  54         for a type that can trivially be dereferenced from the given
  55         <object> is also permitted.  An example is to ask for a
  56         "tree" with <object> being a commit object that contains it,
  57         or to ask for a "blob" with <object> being a tag object that
  58         points at it.
  59
  60 --textconv::
  61         Show the content as transformed by a textconv filter. In this case,
  62         <object> has to be of the form <tree-ish>:<path>, or :<path> in
  63         order to apply the filter to the content recorded in the index at
  64         <path>.
  65
  66 --filters::
  67         Show the content as converted by the filters configured in
  68         the current working tree for the given <path> (i.e. smudge filters,
  69         end-of-line conversion, etc). In this case, <object> has to be of
  70         the form <tree-ish>:<path>, or :<path>.
  71
  72 --path=<path>::
  73         For use with --textconv or --filters, to allow specifying an object
  74         name and a path separately, e.g. when it is difficult to figure out
  75         the revision from which the blob came.
  76
  77 --batch::
  78 --batch=<format>::
  79         Print object information and contents for each object provided
  80         on stdin.  May not be combined with any other options or arguments
  81         except `--textconv` or `--filters`, in which case the input lines
  82         also need to specify the path, separated by white space.  See the
  83         section `BATCH OUTPUT` below for details.
  84
  85 --batch-check::
  86 --batch-check=<format>::
  87         Print object information for each object provided on stdin.  May
  88         not be combined with any other options or arguments except
  89         `--textconv` or `--filters`, in which case the input lines also
  90         need to specify the path, separated by white space.  See the
  91         section `BATCH OUTPUT` below for details.
  92
  93 --batch-all-objects::
  94         Instead of reading a list of objects on stdin, perform the
  95         requested batch operation on all objects in the repository and
  96         any alternate object stores (not just reachable objects).
  97         Requires `--batch` or `--batch-check` be specified. Note that
  98         the objects are visited in order sorted by their hashes.
  99
 100 --buffer::
 101         Normally batch output is flushed after each object is output, so
 102         that a process can interactively read and write from
 103         `cat-file`. With this option, the output uses normal stdio
 104         buffering; this is much more efficient when invoking
 105         `--batch-check` on a large number of objects.
 106
 107 --allow-unknown-type::
 108         Allow -s or -t to query broken/corrupt objects of unknown type.
 109
 110 --follow-symlinks::
 111         With --batch or --batch-check, follow symlinks inside the
 112         repository when requesting objects with extended SHA-1
 113         expressions of the form tree-ish:path-in-tree.  Instead of
 114         providing output about the link itself, provide output about
 115         the linked-to object.  If a symlink points outside the
 116         tree-ish (e.g. a link to /foo or a root-level link to ../foo),
 117         the portion of the link which is outside the tree will be
 118         printed.
 119 +
 120 This option does not (currently) work correctly when an object in the
 121 index is specified (e.g. `:link` instead of `HEAD:link`) rather than
 122 one in the tree.
 123 +
 124 This option cannot (currently) be used unless `--batch` or
 125 `--batch-check` is used.
 126 +
 127 For example, consider a git repository containing:
 128 +
 129 --
 130         f: a file containing "hello\n"
 131         link: a symlink to f
 132         dir/link: a symlink to ../f
 133         plink: a symlink to ../f
 134         alink: a symlink to /etc/passwd
 135 --
 136 +
 137 For a regular file `f`, `echo HEAD:f | git cat-file --batch` would print
 138 +
 139 --
 140         ce013625030ba8dba906f756967f9e9ca394464a blob 6
 141 --
 142 +
 143 And `echo HEAD:link | git cat-file --batch --follow-symlinks` would
 144 print the same thing, as would `HEAD:dir/link`, as they both point at
 145 `HEAD:f`.
 146 +
 147 Without `--follow-symlinks`, these would print data about the symlink
 148 itself.  In the case of `HEAD:link`, you would see
 149 +
 150 --
 151         4d1ae35ba2c8ec712fa2a379db44ad639ca277bd blob 1
 152 --
 153 +
 154 Both `plink` and `alink` point outside the tree, so they would
 155 respectively print:
 156 +
 157 --
 158         symlink 4
 159         ../f
 160
 161         symlink 11
 162         /etc/passwd
 163 --
 164
 165
 166 OUTPUT
 167 ------
 168 If `-t` is specified, one of the <type>.
 169
 170 If `-s` is specified, the size of the <object> in bytes.
 171
 172 If `-e` is specified, no output, unless the <object> is malformed.
 173
 174 If `-p` is specified, the contents of <object> are pretty-printed.
 175
 176 If <type> is specified, the raw (though uncompressed) contents of the <object>
 177 will be returned.
 178
 179 BATCH OUTPUT
 180 ------------
 181
 182 If `--batch` or `--batch-check` is given, `cat-file` will read objects
 183 from stdin, one per line, and print information about them. By default,
 184 the whole line is considered as an object, as if it were fed to
 185 linkgit:git-rev-parse[1].
 186
 187 You can specify the information shown for each object by using a custom
 188 `<format>`. The `<format>` is copied literally to stdout for each
 189 object, with placeholders of the form `%(atom)` expanded, followed by a
 190 newline. The available atoms are:
 191
 192 `objectname`::
 193         The 40-hex object name of the object.
 194
 195 `objecttype`::
 196         The type of the object (the same as `cat-file -t` reports).
 197
 198 `objectsize`::
 199         The size, in bytes, of the object (the same as `cat-file -s`
 200         reports).
 201
 202 `objectsize:disk`::
 203         The size, in bytes, that the object takes up on disk. See the
 204         note about on-disk sizes in the `CAVEATS` section below.
 205
 206 `deltabase`::
 207         If the object is stored as a delta on-disk, this expands to the
 208         40-hex sha1 of the delta base object. Otherwise, expands to the
 209         null sha1 (40 zeroes). See `CAVEATS` below.
 210
 211 `rest`::
 212         If this atom is used in the output string, input lines are split
 213         at the first whitespace boundary. All characters before that
 214         whitespace are considered to be the object name; characters
 215         after that first run of whitespace (i.e., the "rest" of the
 216         line) are output in place of the `%(rest)` atom.
 217
 218 If no format is specified, the default format is `%(objectname)
 219 %(objecttype) %(objectsize)`.
 220
 221 If `--batch` is specified, the object information is followed by the
 222 object contents (consisting of `%(objectsize)` bytes), followed by a
 223 newline.
 224
 225 For example, `--batch` without a custom format would produce:
 226
 227 ------------
 228 <sha1> SP <type> SP <size> LF
 229 <contents> LF
 230 ------------
 231
 232 Whereas `--batch-check='%(objectname) %(objecttype)'` would produce:
 233
 234 ------------
 235 <sha1> SP <type> LF
 236 ------------
 237
 238 If a name is specified on stdin that cannot be resolved to an object in
 239 the repository, then `cat-file` will ignore any custom format and print:
 240
 241 ------------
 242 <object> SP missing LF
 243 ------------
 244
 245 If --follow-symlinks is used, and a symlink in the repository points
 246 outside the repository, then `cat-file` will ignore any custom format
 247 and print:
 248
 249 ------------
 250 symlink SP <size> LF
 251 <symlink> LF
 252 ------------
 253
 254 The symlink will either be absolute (beginning with a /), or relative
 255 to the tree root.  For instance, if dir/link points to ../../foo, then
 256 <symlink> will be ../foo.  <size> is the size of the symlink in bytes.
 257
 258 If --follow-symlinks is used, the following error messages will be
 259 displayed:
 260
 261 ------------
 262 <object> SP missing LF
 263 ------------
 264 is printed when the initial symlink requested does not exist.
 265
 266 ------------
 267 dangling SP <size> LF
 268 <object> LF
 269 ------------
 270 is printed when the initial symlink exists, but something that
 271 it (transitive-of) points to does not.
 272
 273 ------------
 274 loop SP <size> LF
 275 <object> LF
 276 ------------
 277 is printed for symlink loops (or any symlinks that
 278 require more than 40 link resolutions to resolve).
 279
 280 ------------
 281 notdir SP <size> LF
 282 <object> LF
 283 ------------
 284 is printed when, during symlink resolution, a file is used as a
 285 directory name.
 286
 287 CAVEATS
 288 -------
 289
 290 Note that the sizes of objects on disk are reported accurately, but care
 291 should be taken in drawing conclusions about which refs or objects are
 292 responsible for disk usage. The size of a packed non-delta object may be
 293 much larger than the size of objects which delta against it, but the
 294 choice of which object is the base and which is the delta is arbitrary
 295 and is subject to change during a repack.
 296
 297 Note also that multiple copies of an object may be present in the object
 298 database; in this case, it is undefined which copy's size or delta base
 299 will be reported.
 300
 301 GIT
 302 ---
 303 Part of the linkgit:git[1] suite