rev-parse --glob
[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 'git rev-parse' [ --option ] <args>...
12
13 DESCRIPTION
14 -----------
15
16 Many git porcelainish commands take mixture of flags
17 (i.e. parameters that begin with a dash '-') and parameters
18 meant for the underlying 'git-rev-list' command they use internally
19 and flags and parameters for the other commands they use
20 downstream of 'git-rev-list'. This command is used to
21 distinguish between them.
22
23
24 OPTIONS
25 -------
26 --parseopt::
27 Use 'git-rev-parse' in option parsing mode (see PARSEOPT section below).
28
29 --keep-dashdash::
30 Only meaningful in `--parseopt` mode. Tells the option parser to echo
31 out the first `--` met instead of skipping it.
32
33 --stop-at-non-option::
34 Only meaningful in `--parseopt` mode. Lets the option parser stop at
35 the first non-option argument. This can be used to parse sub-commands
36 that take options themself.
37
38 --sq-quote::
39 Use 'git-rev-parse' in shell quoting mode (see SQ-QUOTE
40 section below). In contrast to the `--sq` option below, this
41 mode does only quoting. Nothing else is done to command input.
42
43 --revs-only::
44 Do not output flags and parameters not meant for
45 'git-rev-list' command.
46
47 --no-revs::
48 Do not output flags and parameters meant for
49 'git-rev-list' command.
50
51 --flags::
52 Do not output non-flag parameters.
53
54 --no-flags::
55 Do not output flag parameters.
56
57 --default <arg>::
58 If there is no parameter given by the user, use `<arg>`
59 instead.
60
61 --verify::
62 The parameter given must be usable as a single, valid
63 object name. Otherwise barf and abort.
64
65 -q::
66 --quiet::
67 Only meaningful in `--verify` mode. Do not output an error
68 message if the first argument is not a valid object name;
69 instead exit with non-zero status silently.
70
71 --sq::
72 Usually the output is made one line per flag and
73 parameter. This option makes output a single line,
74 properly quoted for consumption by shell. Useful when
75 you expect your parameter to contain whitespaces and
76 newlines (e.g. when using pickaxe `-S` with
77 'git-diff-\*'). In contrast to the `--sq-quote` option,
78 the command input is still interpreted as usual.
79
80 --not::
81 When showing object names, prefix them with '{caret}' and
82 strip '{caret}' prefix from the object names that already have
83 one.
84
85 --symbolic::
86 Usually the object names are output in SHA1 form (with
87 possible '{caret}' prefix); this option makes them output in a
88 form as close to the original input as possible.
89
90 --symbolic-full-name::
91 This is similar to \--symbolic, but it omits input that
92 are not refs (i.e. branch or tag names; or more
93 explicitly disambiguating "heads/master" form, when you
94 want to name the "master" branch when there is an
95 unfortunately named tag "master"), and show them as full
96 refnames (e.g. "refs/heads/master").
97
98 --abbrev-ref[={strict|loose}]::
99 A non-ambiguous short name of the objects name.
100 The option core.warnAmbiguousRefs is used to select the strict
101 abbreviation mode.
102
103 --all::
104 Show all refs found in `$GIT_DIR/refs`.
105
106 --branches::
107 Show branch refs found in `$GIT_DIR/refs/heads`.
108
109 --tags::
110 Show tag refs found in `$GIT_DIR/refs/tags`.
111
112 --remotes::
113 Show tag refs found in `$GIT_DIR/refs/remotes`.
114
115 --glob=glob-pattern::
116 Show refs matching shell glob pattern `glob-pattern`. If pattern
117 specified lacks leading 'refs/', it is automatically prepended.
118 If pattern lacks '?', '*', or '[', '/*' at the end is impiled.
119
120 --show-prefix::
121 When the command is invoked from a subdirectory, show the
122 path of the current directory relative to the top-level
123 directory.
124
125 --show-cdup::
126 When the command is invoked from a subdirectory, show the
127 path of the top-level directory relative to the current
128 directory (typically a sequence of "../", or an empty string).
129
130 --git-dir::
131 Show `$GIT_DIR` if defined else show the path to the .git directory.
132
133 --is-inside-git-dir::
134 When the current working directory is below the repository
135 directory print "true", otherwise "false".
136
137 --is-inside-work-tree::
138 When the current working directory is inside the work tree of the
139 repository print "true", otherwise "false".
140
141 --is-bare-repository::
142 When the repository is bare print "true", otherwise "false".
143
144 --short::
145 --short=number::
146 Instead of outputting the full SHA1 values of object names try to
147 abbreviate them to a shorter unique name. When no length is specified
148 7 is used. The minimum length is 4.
149
150 --since=datestring::
151 --after=datestring::
152 Parse the date string, and output the corresponding
153 --max-age= parameter for 'git-rev-list'.
154
155 --until=datestring::
156 --before=datestring::
157 Parse the date string, and output the corresponding
158 --min-age= parameter for 'git-rev-list'.
159
160 <args>...::
161 Flags and parameters to be parsed.
162
163
164 SPECIFYING REVISIONS
165 --------------------
166
167 A revision parameter typically, but not necessarily, names a
168 commit object. They use what is called an 'extended SHA1'
169 syntax. Here are various ways to spell object names. The
170 ones listed near the end of this list are to name trees and
171 blobs contained in a commit.
172
173 * The full SHA1 object name (40-byte hexadecimal string), or
174 a substring of such that is unique within the repository.
175 E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
176 name the same commit object if there are no other object in
177 your repository whose object name starts with dae86e.
178
179 * An output from 'git-describe'; i.e. a closest tag, optionally
180 followed by a dash and a number of commits, followed by a dash, a
181 `g`, and an abbreviated object name.
182
183 * A symbolic ref name. E.g. 'master' typically means the commit
184 object referenced by $GIT_DIR/refs/heads/master. If you
185 happen to have both heads/master and tags/master, you can
186 explicitly say 'heads/master' to tell git which one you mean.
187 When ambiguous, a `<name>` is disambiguated by taking the
188 first match in the following rules:
189
190 . if `$GIT_DIR/<name>` exists, that is what you mean (this is usually
191 useful only for `HEAD`, `FETCH_HEAD`, `ORIG_HEAD` and `MERGE_HEAD`);
192
193 . otherwise, `$GIT_DIR/refs/<name>` if exists;
194
195 . otherwise, `$GIT_DIR/refs/tags/<name>` if exists;
196
197 . otherwise, `$GIT_DIR/refs/heads/<name>` if exists;
198
199 . otherwise, `$GIT_DIR/refs/remotes/<name>` if exists;
200
201 . otherwise, `$GIT_DIR/refs/remotes/<name>/HEAD` if exists.
202 +
203 HEAD names the commit your changes in the working tree is based on.
204 FETCH_HEAD records the branch you fetched from a remote repository
205 with your last 'git-fetch' invocation.
206 ORIG_HEAD is created by commands that moves your HEAD in a drastic
207 way, to record the position of the HEAD before their operation, so that
208 you can change the tip of the branch back to the state before you ran
209 them easily.
210 MERGE_HEAD records the commit(s) you are merging into your branch
211 when you run 'git-merge'.
212
213 * A ref followed by the suffix '@' with a date specification
214 enclosed in a brace
215 pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1
216 second ago\}' or '\{1979-02-26 18:30:00\}') to specify the value
217 of the ref at a prior point in time. This suffix may only be
218 used immediately following a ref name and the ref must have an
219 existing log ($GIT_DIR/logs/<ref>). Note that this looks up the state
220 of your *local* ref at a given time; e.g., what was in your local
221 `master` branch last week. If you want to look at commits made during
222 certain times, see `--since` and `--until`.
223
224 * A ref followed by the suffix '@' with an ordinal specification
225 enclosed in a brace pair (e.g. '\{1\}', '\{15\}') to specify
226 the n-th prior value of that ref. For example 'master@\{1\}'
227 is the immediate prior value of 'master' while 'master@\{5\}'
228 is the 5th prior value of 'master'. This suffix may only be used
229 immediately following a ref name and the ref must have an existing
230 log ($GIT_DIR/logs/<ref>).
231
232 * You can use the '@' construct with an empty ref part to get at a
233 reflog of the current branch. For example, if you are on the
234 branch 'blabla', then '@\{1\}' means the same as 'blabla@\{1\}'.
235
236 * The special construct '@\{-<n>\}' means the <n>th branch checked out
237 before the current one.
238
239 * A suffix '{caret}' to a revision parameter means the first parent of
240 that commit object. '{caret}<n>' means the <n>th parent (i.e.
241 'rev{caret}'
242 is equivalent to 'rev{caret}1'). As a special rule,
243 'rev{caret}0' means the commit itself and is used when 'rev' is the
244 object name of a tag object that refers to a commit object.
245
246 * A suffix '{tilde}<n>' to a revision parameter means the commit
247 object that is the <n>th generation grand-parent of the named
248 commit object, following only the first parent. I.e. rev~3 is
249 equivalent to rev{caret}{caret}{caret} which is equivalent to
250 rev{caret}1{caret}1{caret}1. See below for a illustration of
251 the usage of this form.
252
253 * A suffix '{caret}' followed by an object type name enclosed in
254 brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
255 could be a tag, and dereference the tag recursively until an
256 object of that type is found or the object cannot be
257 dereferenced anymore (in which case, barf). `rev{caret}0`
258 introduced earlier is a short-hand for `rev{caret}\{commit\}`.
259
260 * A suffix '{caret}' followed by an empty brace pair
261 (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag,
262 and dereference the tag recursively until a non-tag object is
263 found.
264
265 * A colon, followed by a slash, followed by a text: this names
266 a commit whose commit message starts with the specified text.
267 This name returns the youngest matching commit which is
268 reachable from any ref. If the commit message starts with a
269 '!', you have to repeat that; the special sequence ':/!',
270 followed by something else than '!' is reserved for now.
271
272 * A suffix ':' followed by a path; this names the blob or tree
273 at the given path in the tree-ish object named by the part
274 before the colon.
275
276 * A colon, optionally followed by a stage number (0 to 3) and a
277 colon, followed by a path; this names a blob object in the
278 index at the given path. Missing stage number (and the colon
279 that follows it) names a stage 0 entry. During a merge, stage
280 1 is the common ancestor, stage 2 is the target branch's version
281 (typically the current branch), and stage 3 is the version from
282 the branch being merged.
283
284 Here is an illustration, by Jon Loeliger. Both commit nodes B
285 and C are parents of commit node A. Parent commits are ordered
286 left-to-right.
287
288 ........................................
289 G H I J
290 \ / \ /
291 D E F
292 \ | / \
293 \ | / |
294 \|/ |
295 B C
296 \ /
297 \ /
298 A
299 ........................................
300
301 A = = A^0
302 B = A^ = A^1 = A~1
303 C = A^2 = A^2
304 D = A^^ = A^1^1 = A~2
305 E = B^2 = A^^2
306 F = B^3 = A^^3
307 G = A^^^ = A^1^1^1 = A~3
308 H = D^2 = B^^2 = A^^^2 = A~2^2
309 I = F^ = B^3^ = A^^3^
310 J = F^2 = B^3^2 = A^^3^2
311
312
313 SPECIFYING RANGES
314 -----------------
315
316 History traversing commands such as 'git-log' operate on a set
317 of commits, not just a single commit. To these commands,
318 specifying a single revision with the notation described in the
319 previous section means the set of commits reachable from that
320 commit, following the commit ancestry chain.
321
322 To exclude commits reachable from a commit, a prefix `{caret}`
323 notation is used. E.g. `{caret}r1 r2` means commits reachable
324 from `r2` but exclude the ones reachable from `r1`.
325
326 This set operation appears so often that there is a shorthand
327 for it. When you have two commits `r1` and `r2` (named according
328 to the syntax explained in SPECIFYING REVISIONS above), you can ask
329 for commits that are reachable from r2 excluding those that are reachable
330 from r1 by `{caret}r1 r2` and it can be written as `r1..r2`.
331
332 A similar notation `r1\...r2` is called symmetric difference
333 of `r1` and `r2` and is defined as
334 `r1 r2 --not $(git merge-base --all r1 r2)`.
335 It is the set of commits that are reachable from either one of
336 `r1` or `r2` but not from both.
337
338 Two other shorthands for naming a set that is formed by a commit
339 and its parent commits exist. The `r1{caret}@` notation means all
340 parents of `r1`. `r1{caret}!` includes commit `r1` but excludes
341 all of its parents.
342
343 Here are a handful of examples:
344
345 D G H D
346 D F G H I J D F
347 ^G D H D
348 ^D B E I J F B
349 B...C G H D E B C
350 ^D B C E I J F B C
351 C^@ I J F
352 F^! D G H D F
353
354 PARSEOPT
355 --------
356
357 In `--parseopt` mode, 'git-rev-parse' helps massaging options to bring to shell
358 scripts the same facilities C builtins have. It works as an option normalizer
359 (e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
360
361 It takes on the standard input the specification of the options to parse and
362 understand, and echoes on the standard output a line suitable for `sh(1)` `eval`
363 to replace the arguments with normalized ones. In case of error, it outputs
364 usage on the standard error stream, and exits with code 129.
365
366 Input Format
367 ~~~~~~~~~~~~
368
369 'git-rev-parse --parseopt' input format is fully text based. It has two parts,
370 separated by a line that contains only `--`. The lines before the separator
371 (should be more than one) are used for the usage.
372 The lines after the separator describe the options.
373
374 Each line of options has this format:
375
376 ------------
377 <opt_spec><flags>* SP+ help LF
378 ------------
379
380 `<opt_spec>`::
381 its format is the short option character, then the long option name
382 separated by a comma. Both parts are not required, though at least one
383 is necessary. `h,help`, `dry-run` and `f` are all three correct
384 `<opt_spec>`.
385
386 `<flags>`::
387 `<flags>` are of `*`, `=`, `?` or `!`.
388 * Use `=` if the option takes an argument.
389
390 * Use `?` to mean that the option is optional (though its use is discouraged).
391
392 * Use `*` to mean that this option should not be listed in the usage
393 generated for the `-h` argument. It's shown for `--help-all` as
394 documented in linkgit:gitcli[7].
395
396 * Use `!` to not make the corresponding negated long option available.
397
398 The remainder of the line, after stripping the spaces, is used
399 as the help associated to the option.
400
401 Blank lines are ignored, and lines that don't match this specification are used
402 as option group headers (start the line with a space to create such
403 lines on purpose).
404
405 Example
406 ~~~~~~~
407
408 ------------
409 OPTS_SPEC="\
410 some-command [options] <args>...
411
412 some-command does foo and bar!
413 --
414 h,help show the help
415
416 foo some nifty option --foo
417 bar= some cool option --bar with an argument
418
419 An option group Header
420 C? option C with an optional argument"
421
422 eval `echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?`
423 ------------
424
425 SQ-QUOTE
426 --------
427
428 In `--sq-quote` mode, 'git-rev-parse' echoes on the standard output a
429 single line suitable for `sh(1)` `eval`. This line is made by
430 normalizing the arguments following `--sq-quote`. Nothing other than
431 quoting the arguments is done.
432
433 If you want command input to still be interpreted as usual by
434 'git-rev-parse' before the output is shell quoted, see the `--sq`
435 option.
436
437 Example
438 ~~~~~~~
439
440 ------------
441 $ cat >your-git-script.sh <<\EOF
442 #!/bin/sh
443 args=$(git rev-parse --sq-quote "$@") # quote user-supplied arguments
444 command="git frotz -n24 $args" # and use it inside a handcrafted
445 # command line
446 eval "$command"
447 EOF
448
449 $ sh your-git-script.sh "a b'c"
450 ------------
451
452 EXAMPLES
453 --------
454
455 * Print the object name of the current commit:
456 +
457 ------------
458 $ git rev-parse --verify HEAD
459 ------------
460
461 * Print the commit object name from the revision in the $REV shell variable:
462 +
463 ------------
464 $ git rev-parse --verify $REV
465 ------------
466 +
467 This will error out if $REV is empty or not a valid revision.
468
469 * Same as above:
470 +
471 ------------
472 $ git rev-parse --default master --verify $REV
473 ------------
474 +
475 but if $REV is empty, the commit object name from master will be printed.
476
477
478 Author
479 ------
480 Written by Linus Torvalds <torvalds@osdl.org> .
481 Junio C Hamano <gitster@pobox.com> and Pierre Habouzit <madcoder@debian.org>
482
483 Documentation
484 --------------
485 Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
486
487 GIT
488 ---
489 Part of the linkgit:git[1] suite