Documentation / git-cat-file.txton commit cat-file: fix a grammo in the man page (16dcc29)
   1git-cat-file(1)
   2===============
   3
   4NAME
   5----
   6git-cat-file - Provide content or type and size information for repository objects
   7
   8
   9SYNOPSIS
  10--------
  11[verse]
  12'git cat-file' (-t [--allow-unknown-type]| -s [--allow-unknown-type]| -e | -p | <type> | --textconv ) <object>
  13'git cat-file' (--batch | --batch-check) [--follow-symlinks]
  14
  15DESCRIPTION
  16-----------
  17In its first form, the command provides the content or the type of an object in
  18the repository. The type is required unless `-t` or `-p` is used to find the
  19object type, or `-s` is used to find the object size, or `--textconv` is used
  20(which implies type "blob").
  21
  22In the second form, a list of objects (separated by linefeeds) is provided on
  23stdin, and the SHA-1, type, and size of each object is printed on stdout.
  24
  25OPTIONS
  26-------
  27<object>::
  28        The name of the object to show.
  29        For a more complete list of ways to spell object names, see
  30        the "SPECIFYING REVISIONS" section in linkgit:gitrevisions[7].
  31
  32-t::
  33        Instead of the content, show the object type identified by
  34        <object>.
  35
  36-s::
  37        Instead of the content, show the object size identified by
  38        <object>.
  39
  40-e::
  41        Suppress all output; instead exit with zero status if <object>
  42        exists and is a valid object.
  43
  44-p::
  45        Pretty-print the contents of <object> based on its type.
  46
  47<type>::
  48        Typically this matches the real type of <object> but asking
  49        for a type that can trivially be dereferenced from the given
  50        <object> is also permitted.  An example is to ask for a
  51        "tree" with <object> being a commit object that contains it,
  52        or to ask for a "blob" with <object> being a tag object that
  53        points at it.
  54
  55--textconv::
  56        Show the content as transformed by a textconv filter. In this case,
  57        <object> has to be of the form <tree-ish>:<path>, or :<path> in
  58        order to apply the filter to the content recorded in the index at
  59        <path>.
  60
  61--batch::
  62--batch=<format>::
  63        Print object information and contents for each object provided
  64        on stdin.  May not be combined with any other options or arguments.
  65        See the section `BATCH OUTPUT` below for details.
  66
  67--batch-check::
  68--batch-check=<format>::
  69        Print object information for each object provided on stdin.  May
  70        not be combined with any other options or arguments.  See the
  71        section `BATCH OUTPUT` below for details.
  72
  73--batch-all-objects::
  74        Instead of reading a list of objects on stdin, perform the
  75        requested batch operation on all objects in the repository and
  76        any alternate object stores (not just reachable objects).
  77        Requires `--batch` or `--batch-check` be specified. Note that
  78        the objects are visited in order sorted by their hashes.
  79
  80--buffer::
  81        Normally batch output is flushed after each object is output, so
  82        that a process can interactively read and write from
  83        `cat-file`. With this option, the output uses normal stdio
  84        buffering; this is much more efficient when invoking
  85        `--batch-check` on a large number of objects.
  86
  87--allow-unknown-type::
  88        Allow -s or -t to query broken/corrupt objects of unknown type.
  89
  90--follow-symlinks::
  91        With --batch or --batch-check, follow symlinks inside the
  92        repository when requesting objects with extended SHA-1
  93        expressions of the form tree-ish:path-in-tree.  Instead of
  94        providing output about the link itself, provide output about
  95        the linked-to object.  If a symlink points outside the
  96        tree-ish (e.g. a link to /foo or a root-level link to ../foo),
  97        the portion of the link which is outside the tree will be
  98        printed.
  99+
 100This option does not (currently) work correctly when an object in the
 101index is specified (e.g. `:link` instead of `HEAD:link`) rather than
 102one in the tree.
 103+
 104This option cannot (currently) be used unless `--batch` or
 105`--batch-check` is used.
 106+
 107For example, consider a git repository containing:
 108+
 109--
 110        f: a file containing "hello\n"
 111        link: a symlink to f
 112        dir/link: a symlink to ../f
 113        plink: a symlink to ../f
 114        alink: a symlink to /etc/passwd
 115--
 116+
 117For a regular file `f`, `echo HEAD:f | git cat-file --batch` would print
 118+
 119--
 120        ce013625030ba8dba906f756967f9e9ca394464a blob 6
 121--
 122+
 123And `echo HEAD:link | git cat-file --batch --follow-symlinks` would
 124print the same thing, as would `HEAD:dir/link`, as they both point at
 125`HEAD:f`.
 126+
 127Without `--follow-symlinks`, these would print data about the symlink
 128itself.  In the case of `HEAD:link`, you would see
 129+
 130--
 131        4d1ae35ba2c8ec712fa2a379db44ad639ca277bd blob 1
 132--
 133+
 134Both `plink` and `alink` point outside the tree, so they would
 135respectively print:
 136+
 137--
 138        symlink 4
 139        ../f
 140
 141        symlink 11
 142        /etc/passwd
 143--
 144
 145
 146OUTPUT
 147------
 148If `-t` is specified, one of the <type>.
 149
 150If `-s` is specified, the size of the <object> in bytes.
 151
 152If `-e` is specified, no output.
 153
 154If `-p` is specified, the contents of <object> are pretty-printed.
 155
 156If <type> is specified, the raw (though uncompressed) contents of the <object>
 157will be returned.
 158
 159BATCH OUTPUT
 160------------
 161
 162If `--batch` or `--batch-check` is given, `cat-file` will read objects
 163from stdin, one per line, and print information about them. By default,
 164the whole line is considered as an object, as if it were fed to
 165linkgit:git-rev-parse[1].
 166
 167You can specify the information shown for each object by using a custom
 168`<format>`. The `<format>` is copied literally to stdout for each
 169object, with placeholders of the form `%(atom)` expanded, followed by a
 170newline. The available atoms are:
 171
 172`objectname`::
 173        The 40-hex object name of the object.
 174
 175`objecttype`::
 176        The type of of the object (the same as `cat-file -t` reports).
 177
 178`objectsize`::
 179        The size, in bytes, of the object (the same as `cat-file -s`
 180        reports).
 181
 182`objectsize:disk`::
 183        The size, in bytes, that the object takes up on disk. See the
 184        note about on-disk sizes in the `CAVEATS` section below.
 185
 186`deltabase`::
 187        If the object is stored as a delta on-disk, this expands to the
 188        40-hex sha1 of the delta base object. Otherwise, expands to the
 189        null sha1 (40 zeroes). See `CAVEATS` below.
 190
 191`rest`::
 192        If this atom is used in the output string, input lines are split
 193        at the first whitespace boundary. All characters before that
 194        whitespace are considered to be the object name; characters
 195        after that first run of whitespace (i.e., the "rest" of the
 196        line) are output in place of the `%(rest)` atom.
 197
 198If no format is specified, the default format is `%(objectname)
 199%(objecttype) %(objectsize)`.
 200
 201If `--batch` is specified, the object information is followed by the
 202object contents (consisting of `%(objectsize)` bytes), followed by a
 203newline.
 204
 205For example, `--batch` without a custom format would produce:
 206
 207------------
 208<sha1> SP <type> SP <size> LF
 209<contents> LF
 210------------
 211
 212Whereas `--batch-check='%(objectname) %(objecttype)'` would produce:
 213
 214------------
 215<sha1> SP <type> LF
 216------------
 217
 218If a name is specified on stdin that cannot be resolved to an object in
 219the repository, then `cat-file` will ignore any custom format and print:
 220
 221------------
 222<object> SP missing LF
 223------------
 224
 225If --follow-symlinks is used, and a symlink in the repository points
 226outside the repository, then `cat-file` will ignore any custom format
 227and print:
 228
 229------------
 230symlink SP <size> LF
 231<symlink> LF
 232------------
 233
 234The symlink will either be absolute (beginning with a /), or relative
 235to the tree root.  For instance, if dir/link points to ../../foo, then
 236<symlink> will be ../foo.  <size> is the size of the symlink in bytes.
 237
 238If --follow-symlinks is used, the following error messages will be
 239displayed:
 240
 241------------
 242<object> SP missing LF
 243------------
 244is printed when the initial symlink requested does not exist.
 245
 246------------
 247dangling SP <size> LF
 248<object> LF
 249------------
 250is printed when the initial symlink exists, but something that
 251it (transitive-of) points to does not.
 252
 253------------
 254loop SP <size> LF
 255<object> LF
 256------------
 257is printed for symlink loops (or any symlinks that
 258require more than 40 link resolutions to resolve).
 259
 260------------
 261notdir SP <size> LF
 262<object> LF
 263------------
 264is printed when, during symlink resolution, a file is used as a
 265directory name.
 266
 267CAVEATS
 268-------
 269
 270Note that the sizes of objects on disk are reported accurately, but care
 271should be taken in drawing conclusions about which refs or objects are
 272responsible for disk usage. The size of a packed non-delta object may be
 273much larger than the size of objects which delta against it, but the
 274choice of which object is the base and which is the delta is arbitrary
 275and is subject to change during a repack.
 276
 277Note also that multiple copies of an object may be present in the object
 278database; in this case, it is undefined which copy's size or delta base
 279will be reported.
 280
 281GIT
 282---
 283Part of the linkgit:git[1] suite