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t4034: abstract away SHA-1-specific constants
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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
27 whitespace, 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 whitespace. 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 whitespace. 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 --unordered::
108 When `--batch-all-objects` is in use, visit objects in an
109 order which may be more efficient for accessing the object
110 contents than hash order. The exact details of the order are
111 unspecified, but if you do not require a specific order, this
112 should generally result in faster output, especially with
113 `--batch`. Note that `cat-file` will still show each object
114 only once, even if it is stored multiple times in the
115 repository.
116
117 --allow-unknown-type::
118 Allow -s or -t to query broken/corrupt objects of unknown type.
119
120 --follow-symlinks::
121 With --batch or --batch-check, follow symlinks inside the
122 repository when requesting objects with extended SHA-1
123 expressions of the form tree-ish:path-in-tree. Instead of
124 providing output about the link itself, provide output about
125 the linked-to object. If a symlink points outside the
126 tree-ish (e.g. a link to /foo or a root-level link to ../foo),
127 the portion of the link which is outside the tree will be
128 printed.
129 +
130 This option does not (currently) work correctly when an object in the
131 index is specified (e.g. `:link` instead of `HEAD:link`) rather than
132 one in the tree.
133 +
134 This option cannot (currently) be used unless `--batch` or
135 `--batch-check` is used.
136 +
137 For example, consider a git repository containing:
138 +
139 --
140 f: a file containing "hello\n"
141 link: a symlink to f
142 dir/link: a symlink to ../f
143 plink: a symlink to ../f
144 alink: a symlink to /etc/passwd
145 --
146 +
147 For a regular file `f`, `echo HEAD:f | git cat-file --batch` would print
148 +
149 --
150 ce013625030ba8dba906f756967f9e9ca394464a blob 6
151 --
152 +
153 And `echo HEAD:link | git cat-file --batch --follow-symlinks` would
154 print the same thing, as would `HEAD:dir/link`, as they both point at
155 `HEAD:f`.
156 +
157 Without `--follow-symlinks`, these would print data about the symlink
158 itself. In the case of `HEAD:link`, you would see
159 +
160 --
161 4d1ae35ba2c8ec712fa2a379db44ad639ca277bd blob 1
162 --
163 +
164 Both `plink` and `alink` point outside the tree, so they would
165 respectively print:
166 +
167 --
168 symlink 4
169 ../f
170
171 symlink 11
172 /etc/passwd
173 --
174
175
176 OUTPUT
177 ------
178 If `-t` is specified, one of the <type>.
179
180 If `-s` is specified, the size of the <object> in bytes.
181
182 If `-e` is specified, no output, unless the <object> is malformed.
183
184 If `-p` is specified, the contents of <object> are pretty-printed.
185
186 If <type> is specified, the raw (though uncompressed) contents of the <object>
187 will be returned.
188
189 BATCH OUTPUT
190 ------------
191
192 If `--batch` or `--batch-check` is given, `cat-file` will read objects
193 from stdin, one per line, and print information about them. By default,
194 the whole line is considered as an object, as if it were fed to
195 linkgit:git-rev-parse[1].
196
197 You can specify the information shown for each object by using a custom
198 `<format>`. The `<format>` is copied literally to stdout for each
199 object, with placeholders of the form `%(atom)` expanded, followed by a
200 newline. The available atoms are:
201
202 `objectname`::
203 The 40-hex object name of the object.
204
205 `objecttype`::
206 The type of the object (the same as `cat-file -t` reports).
207
208 `objectsize`::
209 The size, in bytes, of the object (the same as `cat-file -s`
210 reports).
211
212 `objectsize:disk`::
213 The size, in bytes, that the object takes up on disk. See the
214 note about on-disk sizes in the `CAVEATS` section below.
215
216 `deltabase`::
217 If the object is stored as a delta on-disk, this expands to the
218 40-hex sha1 of the delta base object. Otherwise, expands to the
219 null sha1 (40 zeroes). See `CAVEATS` below.
220
221 `rest`::
222 If this atom is used in the output string, input lines are split
223 at the first whitespace boundary. All characters before that
224 whitespace are considered to be the object name; characters
225 after that first run of whitespace (i.e., the "rest" of the
226 line) are output in place of the `%(rest)` atom.
227
228 If no format is specified, the default format is `%(objectname)
229 %(objecttype) %(objectsize)`.
230
231 If `--batch` is specified, the object information is followed by the
232 object contents (consisting of `%(objectsize)` bytes), followed by a
233 newline.
234
235 For example, `--batch` without a custom format would produce:
236
237 ------------
238 <sha1> SP <type> SP <size> LF
239 <contents> LF
240 ------------
241
242 Whereas `--batch-check='%(objectname) %(objecttype)'` would produce:
243
244 ------------
245 <sha1> SP <type> LF
246 ------------
247
248 If a name is specified on stdin that cannot be resolved to an object in
249 the repository, then `cat-file` will ignore any custom format and print:
250
251 ------------
252 <object> SP missing LF
253 ------------
254
255 If a name is specified that might refer to more than one object (an ambiguous short sha), then `cat-file` will ignore any custom format and print:
256
257 ------------
258 <object> SP ambiguous LF
259 ------------
260
261 If --follow-symlinks is used, and a symlink in the repository points
262 outside the repository, then `cat-file` will ignore any custom format
263 and print:
264
265 ------------
266 symlink SP <size> LF
267 <symlink> LF
268 ------------
269
270 The symlink will either be absolute (beginning with a /), or relative
271 to the tree root. For instance, if dir/link points to ../../foo, then
272 <symlink> will be ../foo. <size> is the size of the symlink in bytes.
273
274 If --follow-symlinks is used, the following error messages will be
275 displayed:
276
277 ------------
278 <object> SP missing LF
279 ------------
280 is printed when the initial symlink requested does not exist.
281
282 ------------
283 dangling SP <size> LF
284 <object> LF
285 ------------
286 is printed when the initial symlink exists, but something that
287 it (transitive-of) points to does not.
288
289 ------------
290 loop SP <size> LF
291 <object> LF
292 ------------
293 is printed for symlink loops (or any symlinks that
294 require more than 40 link resolutions to resolve).
295
296 ------------
297 notdir SP <size> LF
298 <object> LF
299 ------------
300 is printed when, during symlink resolution, a file is used as a
301 directory name.
302
303 CAVEATS
304 -------
305
306 Note that the sizes of objects on disk are reported accurately, but care
307 should be taken in drawing conclusions about which refs or objects are
308 responsible for disk usage. The size of a packed non-delta object may be
309 much larger than the size of objects which delta against it, but the
310 choice of which object is the base and which is the delta is arbitrary
311 and is subject to change during a repack.
312
313 Note also that multiple copies of an object may be present in the object
314 database; in this case, it is undefined which copy's size or delta base
315 will be reported.
316
317 GIT
318 ---
319 Part of the linkgit:git[1] suite