Documentation: format full commands in typewriter font
[git/git.git] / Documentation / git-rev-parse.txt
CommitLineData
7fc9d69f
JH
1git-rev-parse(1)
2================
3
4NAME
5----
7bd7f280 6git-rev-parse - Pick out and massage parameters
7fc9d69f
JH
7
8
9SYNOPSIS
10--------
b1889c36 11'git rev-parse' [ --option ] <args>...
7fc9d69f
JH
12
13DESCRIPTION
14-----------
5077fa9c 15
abda1ef5 16Many git porcelainish commands take mixture of flags
5077fa9c 17(i.e. parameters that begin with a dash '-') and parameters
ba020ef5 18meant for the underlying 'git-rev-list' command they use internally
483bc4f0 19and flags and parameters for the other commands they use
ba020ef5 20downstream of 'git-rev-list'. This command is used to
5077fa9c 21distinguish between them.
7fc9d69f
JH
22
23
24OPTIONS
25-------
21d47835 26--parseopt::
ba020ef5 27 Use 'git-rev-parse' in option parsing mode (see PARSEOPT section below).
21d47835 28
2163e3f7 29--keep-dashdash::
21d47835
PH
30 Only meaningful in `--parseopt` mode. Tells the option parser to echo
31 out the first `--` met instead of skipping it.
32
6e0800ef
UKK
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
50325377
CC
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
5077fa9c
JH
43--revs-only::
44 Do not output flags and parameters not meant for
ba020ef5 45 'git-rev-list' command.
5077fa9c
JH
46
47--no-revs::
48 Do not output flags and parameters meant for
ba020ef5 49 'git-rev-list' command.
5077fa9c
JH
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
3240240f
SB
65-q::
66--quiet::
b1b35969
CC
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
5077fa9c
JH
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
50325377
CC
77 'git-diff-\*'). In contrast to the `--sq-quote` option,
78 the command input is still interpreted as usual.
5077fa9c
JH
79
80--not::
babfaba2
JF
81 When showing object names, prefix them with '{caret}' and
82 strip '{caret}' prefix from the object names that already have
5077fa9c
JH
83 one.
84
85--symbolic::
86 Usually the object names are output in SHA1 form (with
babfaba2 87 possible '{caret}' prefix); this option makes them output in a
5077fa9c
JH
88 form as close to the original input as possible.
89
a6d97d49
JH
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").
5077fa9c 97
a45d3469
BW
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
5077fa9c
JH
103--all::
104 Show all refs found in `$GIT_DIR/refs`.
105
a62be77f
SE
106--branches::
107 Show branch refs found in `$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
5077fa9c 115--show-prefix::
5f94c730 116 When the command is invoked from a subdirectory, show the
5077fa9c
JH
117 path of the current directory relative to the top-level
118 directory.
7fc9d69f 119
5f94c730
JH
120--show-cdup::
121 When the command is invoked from a subdirectory, show the
122 path of the top-level directory relative to the current
123 directory (typically a sequence of "../", or an empty string).
124
735d80b3
JF
125--git-dir::
126 Show `$GIT_DIR` if defined else show the path to the .git directory.
127
c9bf7be2 128--is-inside-git-dir::
4faac246
ML
129 When the current working directory is below the repository
130 directory print "true", otherwise "false".
131
892c41b9
ML
132--is-inside-work-tree::
133 When the current working directory is inside the work tree of the
134 repository print "true", otherwise "false".
135
493c774e
ML
136--is-bare-repository::
137 When the repository is bare print "true", otherwise "false".
c9bf7be2 138
3240240f
SB
139--short::
140--short=number::
735d80b3 141 Instead of outputting the full SHA1 values of object names try to
abda1ef5 142 abbreviate them to a shorter unique name. When no length is specified
735d80b3
JF
143 7 is used. The minimum length is 4.
144
3240240f
SB
145--since=datestring::
146--after=datestring::
483bc4f0 147 Parse the date string, and output the corresponding
ba020ef5 148 --max-age= parameter for 'git-rev-list'.
a3114b34 149
3240240f
SB
150--until=datestring::
151--before=datestring::
483bc4f0 152 Parse the date string, and output the corresponding
ba020ef5 153 --min-age= parameter for 'git-rev-list'.
a3114b34 154
7fc9d69f 155<args>...::
5077fa9c 156 Flags and parameters to be parsed.
7fc9d69f
JH
157
158
3a45f625
JH
159SPECIFYING REVISIONS
160--------------------
161
622ef9df
JH
162A revision parameter typically, but not necessarily, names a
163commit object. They use what is called an 'extended SHA1'
6b09c788
NTND
164syntax. Here are various ways to spell object names. The
165ones listed near the end of this list are to name trees and
166blobs contained in a commit.
3a45f625
JH
167
168* The full SHA1 object name (40-byte hexadecimal string), or
169 a substring of such that is unique within the repository.
170 E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
171 name the same commit object if there are no other object in
172 your repository whose object name starts with dae86e.
173
81b237d5
CEB
174* An output from 'git-describe'; i.e. a closest tag, optionally
175 followed by a dash and a number of commits, followed by a dash, a
176 `g`, and an abbreviated object name.
6b09c788 177
3a45f625
JH
178* A symbolic ref name. E.g. 'master' typically means the commit
179 object referenced by $GIT_DIR/refs/heads/master. If you
180 happen to have both heads/master and tags/master, you can
72e9340c 181 explicitly say 'heads/master' to tell git which one you mean.
0ac30568
JH
182 When ambiguous, a `<name>` is disambiguated by taking the
183 first match in the following rules:
3a45f625 184
0ac30568 185 . if `$GIT_DIR/<name>` exists, that is what you mean (this is usually
fd11ae0b 186 useful only for `HEAD`, `FETCH_HEAD`, `ORIG_HEAD` and `MERGE_HEAD`);
0ac30568
JH
187
188 . otherwise, `$GIT_DIR/refs/<name>` if exists;
189
190 . otherwise, `$GIT_DIR/refs/tags/<name>` if exists;
191
192 . otherwise, `$GIT_DIR/refs/heads/<name>` if exists;
193
194 . otherwise, `$GIT_DIR/refs/remotes/<name>` if exists;
195
196 . otherwise, `$GIT_DIR/refs/remotes/<name>/HEAD` if exists.
fd11ae0b
JH
197+
198HEAD names the commit your changes in the working tree is based on.
199FETCH_HEAD records the branch you fetched from a remote repository
200with your last 'git-fetch' invocation.
201ORIG_HEAD is created by commands that moves your HEAD in a drastic
202way, to record the position of the HEAD before their operation, so that
203you can change the tip of the branch back to the state before you ran
204them easily.
205MERGE_HEAD records the commit(s) you are merging into your branch
206when you run 'git-merge'.
0ac30568
JH
207
208* A ref followed by the suffix '@' with a date specification
209 enclosed in a brace
cce91a2c
SP
210 pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1
211 second ago\}' or '\{1979-02-26 18:30:00\}') to specify the value
212 of the ref at a prior point in time. This suffix may only be
213 used immediately following a ref name and the ref must have an
a0d2ceb2
JK
214 existing log ($GIT_DIR/logs/<ref>). Note that this looks up the state
215 of your *local* ref at a given time; e.g., what was in your local
216 `master` branch last week. If you want to look at commits made during
217 certain times, see `--since` and `--until`.
d556fae2 218
ee53aff4
SP
219* A ref followed by the suffix '@' with an ordinal specification
220 enclosed in a brace pair (e.g. '\{1\}', '\{15\}') to specify
221 the n-th prior value of that ref. For example 'master@\{1\}'
222 is the immediate prior value of 'master' while 'master@\{5\}'
223 is the 5th prior value of 'master'. This suffix may only be used
224 immediately following a ref name and the ref must have an existing
225 log ($GIT_DIR/logs/<ref>).
226
1e5db307
JS
227* You can use the '@' construct with an empty ref part to get at a
228 reflog of the current branch. For example, if you are on the
229 branch 'blabla', then '@\{1\}' means the same as 'blabla@\{1\}'.
230
d18ba221
TR
231* The special construct '@\{-<n>\}' means the <n>th branch checked out
232 before the current one.
233
babfaba2
JF
234* A suffix '{caret}' to a revision parameter means the first parent of
235 that commit object. '{caret}<n>' means the <n>th parent (i.e.
236 'rev{caret}'
237 is equivalent to 'rev{caret}1'). As a special rule,
238 'rev{caret}0' means the commit itself and is used when 'rev' is the
3a45f625
JH
239 object name of a tag object that refers to a commit object.
240
54bd2558 241* A suffix '{tilde}<n>' to a revision parameter means the commit
3a45f625
JH
242 object that is the <n>th generation grand-parent of the named
243 commit object, following only the first parent. I.e. rev~3 is
0ac30568
JH
244 equivalent to rev{caret}{caret}{caret} which is equivalent to
245 rev{caret}1{caret}1{caret}1. See below for a illustration of
246 the usage of this form.
3a45f625 247
622ef9df
JH
248* A suffix '{caret}' followed by an object type name enclosed in
249 brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
250 could be a tag, and dereference the tag recursively until an
251 object of that type is found or the object cannot be
252 dereferenced anymore (in which case, barf). `rev{caret}0`
253 introduced earlier is a short-hand for `rev{caret}\{commit\}`.
254
255* A suffix '{caret}' followed by an empty brace pair
256 (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag,
257 and dereference the tag recursively until a non-tag object is
258 found.
259
28a4d940
JS
260* A colon, followed by a slash, followed by a text: this names
261 a commit whose commit message starts with the specified text.
262 This name returns the youngest matching commit which is
263 reachable from any ref. If the commit message starts with a
264 '!', you have to repeat that; the special sequence ':/!',
265 followed by something else than '!' is reserved for now.
266
6b09c788
NTND
267* A suffix ':' followed by a path; this names the blob or tree
268 at the given path in the tree-ish object named by the part
269 before the colon.
270
271* A colon, optionally followed by a stage number (0 to 3) and a
272 colon, followed by a path; this names a blob object in the
273 index at the given path. Missing stage number (and the colon
a5d86f74 274 that follows it) names a stage 0 entry. During a merge, stage
257a84d9
SG
275 1 is the common ancestor, stage 2 is the target branch's version
276 (typically the current branch), and stage 3 is the version from
277 the branch being merged.
6b09c788 278
da101b82
MV
279Here is an illustration, by Jon Loeliger. Both commit nodes B
280and C are parents of commit node A. Parent commits are ordered
2be8fd08
JH
281left-to-right.
282
df2740b0
MB
283........................................
284G H I J
285 \ / \ /
286 D E F
287 \ | / \
288 \ | / |
289 \|/ |
290 B C
291 \ /
292 \ /
293 A
294........................................
2be8fd08
JH
295
296 A = = A^0
297 B = A^ = A^1 = A~1
298 C = A^2 = A^2
299 D = A^^ = A^1^1 = A~2
300 E = B^2 = A^^2
301 F = B^3 = A^^3
302 G = A^^^ = A^1^1^1 = A~3
303 H = D^2 = B^^2 = A^^^2 = A~2^2
304 I = F^ = B^3^ = A^^3^
305 J = F^2 = B^3^2 = A^^3^2
306
3a45f625 307
be4c7014
JH
308SPECIFYING RANGES
309-----------------
310
ba020ef5 311History traversing commands such as 'git-log' operate on a set
be4c7014
JH
312of commits, not just a single commit. To these commands,
313specifying a single revision with the notation described in the
314previous section means the set of commits reachable from that
315commit, following the commit ancestry chain.
316
317To exclude commits reachable from a commit, a prefix `{caret}`
dcb11263 318notation is used. E.g. `{caret}r1 r2` means commits reachable
be4c7014
JH
319from `r2` but exclude the ones reachable from `r1`.
320
321This set operation appears so often that there is a shorthand
fd11ae0b
JH
322for it. When you have two commits `r1` and `r2` (named according
323to the syntax explained in SPECIFYING REVISIONS above), you can ask
324for commits that are reachable from r2 excluding those that are reachable
dcb11263 325from r1 by `{caret}r1 r2` and it can be written as `r1..r2`.
be4c7014 326
dcb11263 327A similar notation `r1\...r2` is called symmetric difference
be4c7014 328of `r1` and `r2` and is defined as
dcb11263 329`r1 r2 --not $(git merge-base --all r1 r2)`.
e18ee576 330It is the set of commits that are reachable from either one of
be4c7014
JH
331`r1` or `r2` but not from both.
332
62476c8e 333Two other shorthands for naming a set that is formed by a commit
faf466ff 334and its parent commits exist. The `r1{caret}@` notation means all
62476c8e 335parents of `r1`. `r1{caret}!` includes commit `r1` but excludes
faf466ff 336all of its parents.
62476c8e 337
a5d86f74 338Here are a handful of examples:
be4c7014 339
c2c6d930
GP
340 D G H D
341 D F G H I J D F
342 ^G D H D
343 ^D B E I J F B
344 B...C G H D E B C
345 ^D B C E I J F B C
346 C^@ I J F
347 F^! D G H D F
be4c7014 348
21d47835
PH
349PARSEOPT
350--------
351
ba020ef5 352In `--parseopt` mode, 'git-rev-parse' helps massaging options to bring to shell
21d47835
PH
353scripts the same facilities C builtins have. It works as an option normalizer
354(e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
355
356It takes on the standard input the specification of the options to parse and
357understand, and echoes on the standard output a line suitable for `sh(1)` `eval`
358to replace the arguments with normalized ones. In case of error, it outputs
359usage on the standard error stream, and exits with code 129.
360
361Input Format
362~~~~~~~~~~~~
363
ba020ef5 364'git-rev-parse --parseopt' input format is fully text based. It has two parts,
21d47835
PH
365separated by a line that contains only `--`. The lines before the separator
366(should be more than one) are used for the usage.
367The lines after the separator describe the options.
368
369Each line of options has this format:
370
371------------
ff962a3f 372<opt_spec><flags>* SP+ help LF
21d47835
PH
373------------
374
375`<opt_spec>`::
376 its format is the short option character, then the long option name
377 separated by a comma. Both parts are not required, though at least one
378 is necessary. `h,help`, `dry-run` and `f` are all three correct
379 `<opt_spec>`.
380
ff962a3f
PH
381`<flags>`::
382 `<flags>` are of `*`, `=`, `?` or `!`.
383 * Use `=` if the option takes an argument.
384
385 * Use `?` to mean that the option is optional (though its use is discouraged).
386
387 * Use `*` to mean that this option should not be listed in the usage
388 generated for the `-h` argument. It's shown for `--help-all` as
a5af0e2c 389 documented in linkgit:gitcli[7].
ff962a3f
PH
390
391 * Use `!` to not make the corresponding negated long option available.
21d47835
PH
392
393The remainder of the line, after stripping the spaces, is used
394as the help associated to the option.
395
396Blank lines are ignored, and lines that don't match this specification are used
397as option group headers (start the line with a space to create such
398lines on purpose).
399
400Example
401~~~~~~~
402
403------------
404OPTS_SPEC="\
405some-command [options] <args>...
406
407some-command does foo and bar!
408--
409h,help show the help
410
411foo some nifty option --foo
412bar= some cool option --bar with an argument
413
414 An option group Header
415C? option C with an optional argument"
416
b1889c36 417eval `echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?`
21d47835
PH
418------------
419
50325377
CC
420SQ-QUOTE
421--------
422
423In `--sq-quote` mode, 'git-rev-parse' echoes on the standard output a
424single line suitable for `sh(1)` `eval`. This line is made by
425normalizing the arguments following `--sq-quote`. Nothing other than
426quoting the arguments is done.
427
428If you want command input to still be interpreted as usual by
429'git-rev-parse' before the output is shell quoted, see the `--sq`
430option.
431
432Example
433~~~~~~~
434
435------------
436$ cat >your-git-script.sh <<\EOF
437#!/bin/sh
438args=$(git rev-parse --sq-quote "$@") # quote user-supplied arguments
439command="git frotz -n24 $args" # and use it inside a handcrafted
440 # command line
441eval "$command"
442EOF
443
444$ sh your-git-script.sh "a b'c"
445------------
446
824b5dc2
CC
447EXAMPLES
448--------
449
450* Print the object name of the current commit:
451+
452------------
453$ git rev-parse --verify HEAD
454------------
455
456* Print the commit object name from the revision in the $REV shell variable:
457+
458------------
459$ git rev-parse --verify $REV
460------------
461+
462This will error out if $REV is empty or not a valid revision.
463
464* Same as above:
465+
466------------
467$ git rev-parse --default master --verify $REV
468------------
469+
470but if $REV is empty, the commit object name from master will be printed.
471
21d47835 472
7fc9d69f
JH
473Author
474------
21d47835 475Written by Linus Torvalds <torvalds@osdl.org> .
59eb68aa 476Junio C Hamano <gitster@pobox.com> and Pierre Habouzit <madcoder@debian.org>
7fc9d69f
JH
477
478Documentation
479--------------
480Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
481
482GIT
483---
9e1f0a85 484Part of the linkgit:git[1] suite