Merge branch 'jc/ref-excludes'
[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 eval "set -- $(git rev-parse --sq --prefix "$prefix" "$@")"
95 ----
96
97 --verify::
98 Verify that exactly one parameter is provided, and that it
99 can be turned into a raw 20-byte SHA-1 that can be used to
100 access the object database. If so, emit it to the standard
101 output; otherwise, error out.
102 +
103 If you want to make sure that the output actually names an object in
104 your object database and/or can be used as a specific type of object
105 you require, you can add "^{type}" peeling operator to the parameter.
106 For example, `git rev-parse "$VAR^{commit}"` will make sure `$VAR`
107 names an existing object that is a commit-ish (i.e. a commit, or an
108 annotated tag that points at a commit). To make sure that `$VAR`
109 names an existing object of any type, `git rev-parse "$VAR^{object}"`
110 can be used.
111
112 -q::
113 --quiet::
114 Only meaningful in `--verify` mode. Do not output an error
115 message if the first argument is not a valid object name;
116 instead exit with non-zero status silently.
117
118 --sq::
119 Usually the output is made one line per flag and
120 parameter. This option makes output a single line,
121 properly quoted for consumption by shell. Useful when
122 you expect your parameter to contain whitespaces and
123 newlines (e.g. when using pickaxe `-S` with
124 'git diff-{asterisk}'). In contrast to the `--sq-quote` option,
125 the command input is still interpreted as usual.
126
127 --not::
128 When showing object names, prefix them with '{caret}' and
129 strip '{caret}' prefix from the object names that already have
130 one.
131
132 --abbrev-ref[=(strict|loose)]::
133 A non-ambiguous short name of the objects name.
134 The option core.warnAmbiguousRefs is used to select the strict
135 abbreviation mode.
136
137 --short::
138 --short=number::
139 Instead of outputting the full SHA-1 values of object names try to
140 abbreviate them to a shorter unique name. When no length is specified
141 7 is used. The minimum length is 4.
142
143 --symbolic::
144 Usually the object names are output in SHA-1 form (with
145 possible '{caret}' prefix); this option makes them output in a
146 form as close to the original input as possible.
147
148 --symbolic-full-name::
149 This is similar to \--symbolic, but it omits input that
150 are not refs (i.e. branch or tag names; or more
151 explicitly disambiguating "heads/master" form, when you
152 want to name the "master" branch when there is an
153 unfortunately named tag "master"), and show them as full
154 refnames (e.g. "refs/heads/master").
155
156 Options for Objects
157 ~~~~~~~~~~~~~~~~~~~
158
159 --all::
160 Show all refs found in `refs/`.
161
162 --branches[=pattern]::
163 --tags[=pattern]::
164 --remotes[=pattern]::
165 Show all branches, tags, or remote-tracking branches,
166 respectively (i.e., refs found in `refs/heads`,
167 `refs/tags`, or `refs/remotes`, respectively).
168 +
169 If a `pattern` is given, only refs matching the given shell glob are
170 shown. If the pattern does not contain a globbing character (`?`,
171 `*`, or `[`), it is turned into a prefix match by appending `/*`.
172
173 --glob=pattern::
174 Show all refs matching the shell glob pattern `pattern`. If
175 the pattern does not start with `refs/`, this is automatically
176 prepended. If the pattern does not contain a globbing
177 character (`?`, `*`, or `[`), it is turned into a prefix
178 match by appending `/*`.
179
180 --exclude=<glob-pattern>::
181 Do not include refs matching '<glob-pattern>' that the next `--all`,
182 `--branches`, `--tags`, `--remotes`, or `--glob` would otherwise
183 consider. Repetitions of this option accumulate exclusion patterns
184 up to the next `--all`, `--branches`, `--tags`, `--remotes`, or
185 `--glob` option (other options or arguments do not clear
186 accumlated patterns).
187 +
188 The patterns given should not begin with `refs/heads`, `refs/tags`, or
189 `refs/remotes` when applied to `--branches`, `--tags`, or `--remotes`,
190 respectively, and they must begin with `refs/` when applied to `--glob`
191 or `--all`. If a trailing '/{asterisk}' is intended, it must be given
192 explicitly.
193
194 --disambiguate=<prefix>::
195 Show every object whose name begins with the given prefix.
196 The <prefix> must be at least 4 hexadecimal digits long to
197 avoid listing each and every object in the repository by
198 mistake.
199
200 Options for Files
201 ~~~~~~~~~~~~~~~~~
202
203 --local-env-vars::
204 List the GIT_* environment variables that are local to the
205 repository (e.g. GIT_DIR or GIT_WORK_TREE, but not GIT_EDITOR).
206 Only the names of the variables are listed, not their value,
207 even if they are set.
208
209 --git-dir::
210 Show `$GIT_DIR` if defined. Otherwise show the path to
211 the .git directory. The path shown, when relative, is
212 relative to the current working directory.
213 +
214 If `$GIT_DIR` is not defined and the current directory
215 is not detected to lie in a Git repository or work tree
216 print a message to stderr and exit with nonzero status.
217
218 --is-inside-git-dir::
219 When the current working directory is below the repository
220 directory print "true", otherwise "false".
221
222 --is-inside-work-tree::
223 When the current working directory is inside the work tree of the
224 repository print "true", otherwise "false".
225
226 --is-bare-repository::
227 When the repository is bare print "true", otherwise "false".
228
229 --resolve-git-dir <path>::
230 Check if <path> is a valid repository or a gitfile that
231 points at a valid repository, and print the location of the
232 repository. If <path> is a gitfile then the resolved path
233 to the real repository is printed.
234
235 --show-cdup::
236 When the command is invoked from a subdirectory, show the
237 path of the top-level directory relative to the current
238 directory (typically a sequence of "../", or an empty string).
239
240 --show-prefix::
241 When the command is invoked from a subdirectory, show the
242 path of the current directory relative to the top-level
243 directory.
244
245 --show-toplevel::
246 Show the absolute path of the top-level directory.
247
248 Other Options
249 ~~~~~~~~~~~~~
250
251 --since=datestring::
252 --after=datestring::
253 Parse the date string, and output the corresponding
254 --max-age= parameter for 'git rev-list'.
255
256 --until=datestring::
257 --before=datestring::
258 Parse the date string, and output the corresponding
259 --min-age= parameter for 'git rev-list'.
260
261 <args>...::
262 Flags and parameters to be parsed.
263
264
265 include::revisions.txt[]
266
267 PARSEOPT
268 --------
269
270 In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
271 scripts the same facilities C builtins have. It works as an option normalizer
272 (e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
273
274 It takes on the standard input the specification of the options to parse and
275 understand, and echoes on the standard output a string suitable for `sh(1)` `eval`
276 to replace the arguments with normalized ones. In case of error, it outputs
277 usage on the standard error stream, and exits with code 129.
278
279 Note: Make sure you quote the result when passing it to `eval`. See
280 below for an example.
281
282 Input Format
283 ~~~~~~~~~~~~
284
285 'git rev-parse --parseopt' input format is fully text based. It has two parts,
286 separated by a line that contains only `--`. The lines before the separator
287 (should be more than one) are used for the usage.
288 The lines after the separator describe the options.
289
290 Each line of options has this format:
291
292 ------------
293 <opt_spec><flags>* SP+ help LF
294 ------------
295
296 `<opt_spec>`::
297 its format is the short option character, then the long option name
298 separated by a comma. Both parts are not required, though at least one
299 is necessary. `h,help`, `dry-run` and `f` are all three correct
300 `<opt_spec>`.
301
302 `<flags>`::
303 `<flags>` are of `*`, `=`, `?` or `!`.
304 * Use `=` if the option takes an argument.
305
306 * Use `?` to mean that the option takes an optional argument. You
307 probably want to use the `--stuck-long` mode to be able to
308 unambiguously parse the optional argument.
309
310 * Use `*` to mean that this option should not be listed in the usage
311 generated for the `-h` argument. It's shown for `--help-all` as
312 documented in linkgit:gitcli[7].
313
314 * Use `!` to not make the corresponding negated long option available.
315
316 The remainder of the line, after stripping the spaces, is used
317 as the help associated to the option.
318
319 Blank lines are ignored, and lines that don't match this specification are used
320 as option group headers (start the line with a space to create such
321 lines on purpose).
322
323 Example
324 ~~~~~~~
325
326 ------------
327 OPTS_SPEC="\
328 some-command [options] <args>...
329
330 some-command does foo and bar!
331 --
332 h,help show the help
333
334 foo some nifty option --foo
335 bar= some cool option --bar with an argument
336
337 An option group Header
338 C? option C with an optional argument"
339
340 eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"
341 ------------
342
343 SQ-QUOTE
344 --------
345
346 In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
347 single line suitable for `sh(1)` `eval`. This line is made by
348 normalizing the arguments following `--sq-quote`. Nothing other than
349 quoting the arguments is done.
350
351 If you want command input to still be interpreted as usual by
352 'git rev-parse' before the output is shell quoted, see the `--sq`
353 option.
354
355 Example
356 ~~~~~~~
357
358 ------------
359 $ cat >your-git-script.sh <<\EOF
360 #!/bin/sh
361 args=$(git rev-parse --sq-quote "$@") # quote user-supplied arguments
362 command="git frotz -n24 $args" # and use it inside a handcrafted
363 # command line
364 eval "$command"
365 EOF
366
367 $ sh your-git-script.sh "a b'c"
368 ------------
369
370 EXAMPLES
371 --------
372
373 * Print the object name of the current commit:
374 +
375 ------------
376 $ git rev-parse --verify HEAD
377 ------------
378
379 * Print the commit object name from the revision in the $REV shell variable:
380 +
381 ------------
382 $ git rev-parse --verify $REV^{commit}
383 ------------
384 +
385 This will error out if $REV is empty or not a valid revision.
386
387 * Similar to above:
388 +
389 ------------
390 $ git rev-parse --default master --verify $REV
391 ------------
392 +
393 but if $REV is empty, the commit object name from master will be printed.
394
395 GIT
396 ---
397 Part of the linkgit:git[1] suite