Merge branch 'sb/rev-parse-show-superproject-root'
[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 --short[=length]::
130 Same as `--verify` but shortens the object name to a unique
131 prefix with at least `length` characters. The minimum length
132 is 4, the default is the effective value of the `core.abbrev`
133 configuration variable (see linkgit:git-config[1]).
134
135 --not::
136 When showing object names, prefix them with '{caret}' and
137 strip '{caret}' prefix from the object names that already have
138 one.
139
140 --abbrev-ref[=(strict|loose)]::
141 A non-ambiguous short name of the objects name.
142 The option core.warnAmbiguousRefs is used to select the strict
143 abbreviation mode.
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 `$GIT_DIR` is not defined and the current directory
217 is not detected to lie in a Git repository or work tree
218 print a message to stderr and exit with nonzero status.
219
220 --absolute-git-dir::
221 Like `--git-dir`, but its output is always the canonicalized
222 absolute path.
223
224 --git-common-dir::
225 Show `$GIT_COMMON_DIR` if defined, else `$GIT_DIR`.
226
227 --is-inside-git-dir::
228 When the current working directory is below the repository
229 directory print "true", otherwise "false".
230
231 --is-inside-work-tree::
232 When the current working directory is inside the work tree of the
233 repository print "true", otherwise "false".
234
235 --is-bare-repository::
236 When the repository is bare print "true", otherwise "false".
237
238 --is-shallow-repository::
239 When the repository is shallow print "true", otherwise "false".
240
241 --resolve-git-dir <path>::
242 Check if <path> is a valid repository or a gitfile that
243 points at a valid repository, and print the location of the
244 repository. If <path> is a gitfile then the resolved path
245 to the real repository is printed.
246
247 --git-path <path>::
248 Resolve "$GIT_DIR/<path>" and takes other path relocation
249 variables such as $GIT_OBJECT_DIRECTORY,
250 $GIT_INDEX_FILE... into account. For example, if
251 $GIT_OBJECT_DIRECTORY is set to /foo/bar then "git rev-parse
252 --git-path objects/abc" returns /foo/bar/abc.
253
254 --show-cdup::
255 When the command is invoked from a subdirectory, show the
256 path of the top-level directory relative to the current
257 directory (typically a sequence of "../", or an empty string).
258
259 --show-prefix::
260 When the command is invoked from a subdirectory, show the
261 path of the current directory relative to the top-level
262 directory.
263
264 --show-toplevel::
265 Show the absolute path of the top-level directory.
266
267 --show-superproject-working-tree::
268 Show the absolute path of the root of the superproject's
269 working tree (if exists) that uses the current repository as
270 its submodule. Outputs nothing if the current repository is
271 not used as a submodule by any project.
272
273 --shared-index-path::
274 Show the path to the shared index file in split index mode, or
275 empty if not in split-index mode.
276
277 Other Options
278 ~~~~~~~~~~~~~
279
280 --since=datestring::
281 --after=datestring::
282 Parse the date string, and output the corresponding
283 --max-age= parameter for 'git rev-list'.
284
285 --until=datestring::
286 --before=datestring::
287 Parse the date string, and output the corresponding
288 --min-age= parameter for 'git rev-list'.
289
290 <args>...::
291 Flags and parameters to be parsed.
292
293
294 include::revisions.txt[]
295
296 PARSEOPT
297 --------
298
299 In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
300 scripts the same facilities C builtins have. It works as an option normalizer
301 (e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
302
303 It takes on the standard input the specification of the options to parse and
304 understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
305 to replace the arguments with normalized ones. In case of error, it outputs
306 usage on the standard error stream, and exits with code 129.
307
308 Note: Make sure you quote the result when passing it to `eval`. See
309 below for an example.
310
311 Input Format
312 ~~~~~~~~~~~~
313
314 'git rev-parse --parseopt' input format is fully text based. It has two parts,
315 separated by a line that contains only `--`. The lines before the separator
316 (should be one or more) are used for the usage.
317 The lines after the separator describe the options.
318
319 Each line of options has this format:
320
321 ------------
322 <opt-spec><flags>*<arg-hint>? SP+ help LF
323 ------------
324
325 `<opt-spec>`::
326 its format is the short option character, then the long option name
327 separated by a comma. Both parts are not required, though at least one
328 is necessary. May not contain any of the `<flags>` characters.
329 `h,help`, `dry-run` and `f` are examples of correct `<opt-spec>`.
330
331 `<flags>`::
332 `<flags>` are of `*`, `=`, `?` or `!`.
333 * Use `=` if the option takes an argument.
334
335 * Use `?` to mean that the option takes an optional argument. You
336 probably want to use the `--stuck-long` mode to be able to
337 unambiguously parse the optional argument.
338
339 * Use `*` to mean that this option should not be listed in the usage
340 generated for the `-h` argument. It's shown for `--help-all` as
341 documented in linkgit:gitcli[7].
342
343 * Use `!` to not make the corresponding negated long option available.
344
345 `<arg-hint>`::
346 `<arg-hint>`, if specified, is used as a name of the argument in the
347 help output, for options that take arguments. `<arg-hint>` is
348 terminated by the first whitespace. It is customary to use a
349 dash to separate words in a multi-word argument hint.
350
351 The remainder of the line, after stripping the spaces, is used
352 as the help associated to the option.
353
354 Blank lines are ignored, and lines that don't match this specification are used
355 as option group headers (start the line with a space to create such
356 lines on purpose).
357
358 Example
359 ~~~~~~~
360
361 ------------
362 OPTS_SPEC="\
363 some-command [options] <args>...
364
365 some-command does foo and bar!
366 --
367 h,help show the help
368
369 foo some nifty option --foo
370 bar= some cool option --bar with an argument
371 baz=arg another cool option --baz with a named argument
372 qux?path qux may take a path argument but has meaning by itself
373
374 An option group Header
375 C? option C with an optional argument"
376
377 eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
378 ------------
379
380
381 Usage text
382 ~~~~~~~~~~
383
384 When `"$@"` is `-h` or `--help` in the above example, the following
385 usage text would be shown:
386
387 ------------
388 usage: some-command [options] <args>...
389
390 some-command does foo and bar!
391
392 -h, --help show the help
393 --foo some nifty option --foo
394 --bar ... some cool option --bar with an argument
395 --baz <arg> another cool option --baz with a named argument
396 --qux[=<path>] qux may take a path argument but has meaning by itself
397
398 An option group Header
399 -C[...] option C with an optional argument
400 ------------
401
402 SQ-QUOTE
403 --------
404
405 In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
406 single line suitable for `sh(1)` `eval`. This line is made by
407 normalizing the arguments following `--sq-quote`. Nothing other than
408 quoting the arguments is done.
409
410 If you want command input to still be interpreted as usual by
411 'git rev-parse' before the output is shell quoted, see the `--sq`
412 option.
413
414 Example
415 ~~~~~~~
416
417 ------------
418 $ cat >your-git-script.sh <<\EOF
419 #!/bin/sh
420 args=$(git rev-parse --sq-quote "$@") # quote user-supplied arguments
421 command="git frotz -n24 $args" # and use it inside a handcrafted
422 # command line
423 eval "$command"
424 EOF
425
426 $ sh your-git-script.sh "a b'c"
427 ------------
428
429 EXAMPLES
430 --------
431
432 * Print the object name of the current commit:
433 +
434 ------------
435 $ git rev-parse --verify HEAD
436 ------------
437
438 * Print the commit object name from the revision in the $REV shell variable:
439 +
440 ------------
441 $ git rev-parse --verify $REV^{commit}
442 ------------
443 +
444 This will error out if $REV is empty or not a valid revision.
445
446 * Similar to above:
447 +
448 ------------
449 $ git rev-parse --default master --verify $REV
450 ------------
451 +
452 but if $REV is empty, the commit object name from master will be printed.
453
454 GIT
455 ---
456 Part of the linkgit:git[1] suite