Merge branch 'js/status-pre-rebase-i'
[git/git.git] / Documentation / git-rev-parse.txt
1 git-rev-parse(1)
2 ================
3
4 NAME
5 ----
6 git-rev-parse - Pick out and massage parameters
7
8
9 SYNOPSIS
10 --------
11 [verse]
12 'git rev-parse' [ --option ] <args>...
13
14 DESCRIPTION
15 -----------
16
17 Many Git porcelainish commands take mixture of flags
18 (i.e. parameters that begin with a dash '-') and parameters
19 meant for the underlying 'git rev-list' command they use internally
20 and flags and parameters for the other commands they use
21 downstream of 'git rev-list'. This command is used to
22 distinguish between them.
23
24
25 OPTIONS
26 -------
27
28 Operation Modes
29 ~~~~~~~~~~~~~~~
30
31 Each of these options must appear first on the command line.
32
33 --parseopt::
34 Use 'git rev-parse' in option parsing mode (see PARSEOPT section below).
35
36 --sq-quote::
37 Use 'git rev-parse' in shell quoting mode (see SQ-QUOTE
38 section below). In contrast to the `--sq` option below, this
39 mode does only quoting. Nothing else is done to command input.
40
41 Options for --parseopt
42 ~~~~~~~~~~~~~~~~~~~~~~
43
44 --keep-dashdash::
45 Only meaningful in `--parseopt` mode. Tells the option parser to echo
46 out the first `--` met instead of skipping it.
47
48 --stop-at-non-option::
49 Only meaningful in `--parseopt` mode. Lets the option parser stop at
50 the first non-option argument. This can be used to parse sub-commands
51 that take options themselves.
52
53 --stuck-long::
54 Only meaningful in `--parseopt` mode. Output the options in their
55 long form if available, and with their arguments stuck.
56
57 Options for Filtering
58 ~~~~~~~~~~~~~~~~~~~~~
59
60 --revs-only::
61 Do not output flags and parameters not meant for
62 'git rev-list' command.
63
64 --no-revs::
65 Do not output flags and parameters meant for
66 'git rev-list' command.
67
68 --flags::
69 Do not output non-flag parameters.
70
71 --no-flags::
72 Do not output flag parameters.
73
74 Options for Output
75 ~~~~~~~~~~~~~~~~~~
76
77 --default <arg>::
78 If there is no parameter given by the user, use `<arg>`
79 instead.
80
81 --prefix <arg>::
82 Behave as if 'git rev-parse' was invoked from the `<arg>`
83 subdirectory of the working tree. Any relative filenames are
84 resolved as if they are prefixed by `<arg>` and will be printed
85 in that form.
86 +
87 This can be used to convert arguments to a command run in a subdirectory
88 so that they can still be used after moving to the top-level of the
89 repository. For example:
90 +
91 ----
92 prefix=$(git rev-parse --show-prefix)
93 cd "$(git rev-parse --show-toplevel)"
94 # rev-parse provides the -- needed for 'set'
95 eval "set $(git rev-parse --sq --prefix "$prefix" -- "$@")"
96 ----
97
98 --verify::
99 Verify that exactly one parameter is provided, and that it
100 can be turned into a raw 20-byte SHA-1 that can be used to
101 access the object database. If so, emit it to the standard
102 output; otherwise, error out.
103 +
104 If you want to make sure that the output actually names an object in
105 your object database and/or can be used as a specific type of object
106 you require, you can add the `^{type}` peeling operator to the parameter.
107 For example, `git rev-parse "$VAR^{commit}"` will make sure `$VAR`
108 names an existing object that is a commit-ish (i.e. a commit, or an
109 annotated tag that points at a commit). To make sure that `$VAR`
110 names an existing object of any type, `git rev-parse "$VAR^{object}"`
111 can be used.
112
113 -q::
114 --quiet::
115 Only meaningful in `--verify` mode. Do not output an error
116 message if the first argument is not a valid object name;
117 instead exit with non-zero status silently.
118 SHA-1s for valid object names are printed to stdout on success.
119
120 --sq::
121 Usually the output is made one line per flag and
122 parameter. This option makes output a single line,
123 properly quoted for consumption by shell. Useful when
124 you expect your parameter to contain whitespaces and
125 newlines (e.g. when using pickaxe `-S` with
126 'git diff-{asterisk}'). In contrast to the `--sq-quote` option,
127 the command input is still interpreted as usual.
128
129 --not::
130 When showing object names, prefix them with '{caret}' and
131 strip '{caret}' prefix from the object names that already have
132 one.
133
134 --abbrev-ref[=(strict|loose)]::
135 A non-ambiguous short name of the objects name.
136 The option core.warnAmbiguousRefs is used to select the strict
137 abbreviation mode.
138
139 --short::
140 --short=number::
141 Instead of outputting the full SHA-1 values of object names try to
142 abbreviate them to a shorter unique name. When no length is specified
143 7 is used. The minimum length is 4.
144
145 --symbolic::
146 Usually the object names are output in SHA-1 form (with
147 possible '{caret}' prefix); this option makes them output in a
148 form as close to the original input as possible.
149
150 --symbolic-full-name::
151 This is similar to --symbolic, but it omits input that
152 are not refs (i.e. branch or tag names; or more
153 explicitly disambiguating "heads/master" form, when you
154 want to name the "master" branch when there is an
155 unfortunately named tag "master"), and show them as full
156 refnames (e.g. "refs/heads/master").
157
158 Options for Objects
159 ~~~~~~~~~~~~~~~~~~~
160
161 --all::
162 Show all refs found in `refs/`.
163
164 --branches[=pattern]::
165 --tags[=pattern]::
166 --remotes[=pattern]::
167 Show all branches, tags, or remote-tracking branches,
168 respectively (i.e., refs found in `refs/heads`,
169 `refs/tags`, or `refs/remotes`, respectively).
170 +
171 If a `pattern` is given, only refs matching the given shell glob are
172 shown. If the pattern does not contain a globbing character (`?`,
173 `*`, or `[`), it is turned into a prefix match by appending `/*`.
174
175 --glob=pattern::
176 Show all refs matching the shell glob pattern `pattern`. If
177 the pattern does not start with `refs/`, this is automatically
178 prepended. If the pattern does not contain a globbing
179 character (`?`, `*`, or `[`), it is turned into a prefix
180 match by appending `/*`.
181
182 --exclude=<glob-pattern>::
183 Do not include refs matching '<glob-pattern>' that the next `--all`,
184 `--branches`, `--tags`, `--remotes`, or `--glob` would otherwise
185 consider. Repetitions of this option accumulate exclusion patterns
186 up to the next `--all`, `--branches`, `--tags`, `--remotes`, or
187 `--glob` option (other options or arguments do not clear
188 accumulated patterns).
189 +
190 The patterns given should not begin with `refs/heads`, `refs/tags`, or
191 `refs/remotes` when applied to `--branches`, `--tags`, or `--remotes`,
192 respectively, and they must begin with `refs/` when applied to `--glob`
193 or `--all`. If a trailing '/{asterisk}' is intended, it must be given
194 explicitly.
195
196 --disambiguate=<prefix>::
197 Show every object whose name begins with the given prefix.
198 The <prefix> must be at least 4 hexadecimal digits long to
199 avoid listing each and every object in the repository by
200 mistake.
201
202 Options for Files
203 ~~~~~~~~~~~~~~~~~
204
205 --local-env-vars::
206 List the GIT_* environment variables that are local to the
207 repository (e.g. GIT_DIR or GIT_WORK_TREE, but not GIT_EDITOR).
208 Only the names of the variables are listed, not their value,
209 even if they are set.
210
211 --git-dir::
212 Show `$GIT_DIR` if defined. Otherwise show the path to
213 the .git directory. The path shown, when relative, is
214 relative to the current working directory.
215 +
216 If `$GIT_DIR` is not defined and the current directory
217 is not detected to lie in a Git repository or work tree
218 print a message to stderr and exit with nonzero status.
219
220 --git-common-dir::
221 Show `$GIT_COMMON_DIR` if defined, else `$GIT_DIR`.
222
223 --is-inside-git-dir::
224 When the current working directory is below the repository
225 directory print "true", otherwise "false".
226
227 --is-inside-work-tree::
228 When the current working directory is inside the work tree of the
229 repository print "true", otherwise "false".
230
231 --is-bare-repository::
232 When the repository is bare print "true", otherwise "false".
233
234 --resolve-git-dir <path>::
235 Check if <path> is a valid repository or a gitfile that
236 points at a valid repository, and print the location of the
237 repository. If <path> is a gitfile then the resolved path
238 to the real repository is printed.
239
240 --git-path <path>::
241 Resolve "$GIT_DIR/<path>" and takes other path relocation
242 variables such as $GIT_OBJECT_DIRECTORY,
243 $GIT_INDEX_FILE... into account. For example, if
244 $GIT_OBJECT_DIRECTORY is set to /foo/bar then "git rev-parse
245 --git-path objects/abc" returns /foo/bar/abc.
246
247 --show-cdup::
248 When the command is invoked from a subdirectory, show the
249 path of the top-level directory relative to the current
250 directory (typically a sequence of "../", or an empty string).
251
252 --show-prefix::
253 When the command is invoked from a subdirectory, show the
254 path of the current directory relative to the top-level
255 directory.
256
257 --show-toplevel::
258 Show the absolute path of the top-level directory.
259
260 --shared-index-path::
261 Show the path to the shared index file in split index mode, or
262 empty if not in split-index mode.
263
264 Other Options
265 ~~~~~~~~~~~~~
266
267 --since=datestring::
268 --after=datestring::
269 Parse the date string, and output the corresponding
270 --max-age= parameter for 'git rev-list'.
271
272 --until=datestring::
273 --before=datestring::
274 Parse the date string, and output the corresponding
275 --min-age= parameter for 'git rev-list'.
276
277 <args>...::
278 Flags and parameters to be parsed.
279
280
281 include::revisions.txt[]
282
283 PARSEOPT
284 --------
285
286 In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
287 scripts the same facilities C builtins have. It works as an option normalizer
288 (e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
289
290 It takes on the standard input the specification of the options to parse and
291 understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
292 to replace the arguments with normalized ones. In case of error, it outputs
293 usage on the standard error stream, and exits with code 129.
294
295 Note: Make sure you quote the result when passing it to `eval`. See
296 below for an example.
297
298 Input Format
299 ~~~~~~~~~~~~
300
301 'git rev-parse --parseopt' input format is fully text based. It has two parts,
302 separated by a line that contains only `--`. The lines before the separator
303 (should be one or more) are used for the usage.
304 The lines after the separator describe the options.
305
306 Each line of options has this format:
307
308 ------------
309 <opt-spec><flags>*<arg-hint>? SP+ help LF
310 ------------
311
312 `<opt-spec>`::
313 its format is the short option character, then the long option name
314 separated by a comma. Both parts are not required, though at least one
315 is necessary. May not contain any of the `<flags>` characters.
316 `h,help`, `dry-run` and `f` are examples of correct `<opt-spec>`.
317
318 `<flags>`::
319 `<flags>` are of `*`, `=`, `?` or `!`.
320 * Use `=` if the option takes an argument.
321
322 * Use `?` to mean that the option takes an optional argument. You
323 probably want to use the `--stuck-long` mode to be able to
324 unambiguously parse the optional argument.
325
326 * Use `*` to mean that this option should not be listed in the usage
327 generated for the `-h` argument. It's shown for `--help-all` as
328 documented in linkgit:gitcli[7].
329
330 * Use `!` to not make the corresponding negated long option available.
331
332 `<arg-hint>`::
333 `<arg-hint>`, if specified, is used as a name of the argument in the
334 help output, for options that take arguments. `<arg-hint>` is
335 terminated by the first whitespace. It is customary to use a
336 dash to separate words in a multi-word argument hint.
337
338 The remainder of the line, after stripping the spaces, is used
339 as the help associated to the option.
340
341 Blank lines are ignored, and lines that don't match this specification are used
342 as option group headers (start the line with a space to create such
343 lines on purpose).
344
345 Example
346 ~~~~~~~
347
348 ------------
349 OPTS_SPEC="\
350 some-command [options] <args>...
351
352 some-command does foo and bar!
353 --
354 h,help show the help
355
356 foo some nifty option --foo
357 bar= some cool option --bar with an argument
358 baz=arg another cool option --baz with a named argument
359 qux?path qux may take a path argument but has meaning by itself
360
361 An option group Header
362 C? option C with an optional argument"
363
364 eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
365 ------------
366
367
368 Usage text
369 ~~~~~~~~~~
370
371 When `"$@"` is `-h` or `--help` in the above example, the following
372 usage text would be shown:
373
374 ------------
375 usage: some-command [options] <args>...
376
377 some-command does foo and bar!
378
379 -h, --help show the help
380 --foo some nifty option --foo
381 --bar ... some cool option --bar with an argument
382 --baz <arg> another cool option --baz with a named argument
383 --qux[=<path>] qux may take a path argument but has meaning by itself
384
385 An option group Header
386 -C[...] option C with an optional argument
387 ------------
388
389 SQ-QUOTE
390 --------
391
392 In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
393 single line suitable for `sh(1)` `eval`. This line is made by
394 normalizing the arguments following `--sq-quote`. Nothing other than
395 quoting the arguments is done.
396
397 If you want command input to still be interpreted as usual by
398 'git rev-parse' before the output is shell quoted, see the `--sq`
399 option.
400
401 Example
402 ~~~~~~~
403
404 ------------
405 $ cat >your-git-script.sh <<\EOF
406 #!/bin/sh
407 args=$(git rev-parse --sq-quote "$@") # quote user-supplied arguments
408 command="git frotz -n24 $args" # and use it inside a handcrafted
409 # command line
410 eval "$command"
411 EOF
412
413 $ sh your-git-script.sh "a b'c"
414 ------------
415
416 EXAMPLES
417 --------
418
419 * Print the object name of the current commit:
420 +
421 ------------
422 $ git rev-parse --verify HEAD
423 ------------
424
425 * Print the commit object name from the revision in the $REV shell variable:
426 +
427 ------------
428 $ git rev-parse --verify $REV^{commit}
429 ------------
430 +
431 This will error out if $REV is empty or not a valid revision.
432
433 * Similar to above:
434 +
435 ------------
436 $ git rev-parse --default master --verify $REV
437 ------------
438 +
439 but if $REV is empty, the commit object name from master will be printed.
440
441 GIT
442 ---
443 Part of the linkgit:git[1] suite