parseopt: fix documentation for --keep-dashdash
[git/git.git] / Documentation / git-rev-parse.txt
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1git-rev-parse(1)
2================
3
4NAME
5----
7bd7f280 6git-rev-parse - Pick out and massage parameters
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7
8
9SYNOPSIS
10--------
b1889c36 11'git rev-parse' [ --option ] <args>...
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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.
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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::
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30 Only meaningful in `--parseopt` mode. Tells the option parser to echo
31 out the first `--` met instead of skipping it.
32
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33--revs-only::
34 Do not output flags and parameters not meant for
ba020ef5 35 'git-rev-list' command.
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36
37--no-revs::
38 Do not output flags and parameters meant for
ba020ef5 39 'git-rev-list' command.
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40
41--flags::
42 Do not output non-flag parameters.
43
44--no-flags::
45 Do not output flag parameters.
46
47--default <arg>::
48 If there is no parameter given by the user, use `<arg>`
49 instead.
50
51--verify::
52 The parameter given must be usable as a single, valid
53 object name. Otherwise barf and abort.
54
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55-q::
56--quiet::
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57 Only meaningful in `--verify` mode. Do not output an error
58 message if the first argument is not a valid object name;
59 instead exit with non-zero status silently.
60
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61--sq::
62 Usually the output is made one line per flag and
63 parameter. This option makes output a single line,
64 properly quoted for consumption by shell. Useful when
65 you expect your parameter to contain whitespaces and
66 newlines (e.g. when using pickaxe `-S` with
ba020ef5 67 'git-diff-\*').
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68
69--not::
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70 When showing object names, prefix them with '{caret}' and
71 strip '{caret}' prefix from the object names that already have
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72 one.
73
74--symbolic::
75 Usually the object names are output in SHA1 form (with
babfaba2 76 possible '{caret}' prefix); this option makes them output in a
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77 form as close to the original input as possible.
78
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79--symbolic-full-name::
80 This is similar to \--symbolic, but it omits input that
81 are not refs (i.e. branch or tag names; or more
82 explicitly disambiguating "heads/master" form, when you
83 want to name the "master" branch when there is an
84 unfortunately named tag "master"), and show them as full
85 refnames (e.g. "refs/heads/master").
5077fa9c 86
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87--abbrev-ref[={strict|loose}]::
88 A non-ambiguous short name of the objects name.
89 The option core.warnAmbiguousRefs is used to select the strict
90 abbreviation mode.
91
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92--all::
93 Show all refs found in `$GIT_DIR/refs`.
94
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95--branches::
96 Show branch refs found in `$GIT_DIR/refs/heads`.
97
98--tags::
99 Show tag refs found in `$GIT_DIR/refs/tags`.
100
101--remotes::
102 Show tag refs found in `$GIT_DIR/refs/remotes`.
103
5077fa9c 104--show-prefix::
5f94c730 105 When the command is invoked from a subdirectory, show the
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106 path of the current directory relative to the top-level
107 directory.
7fc9d69f 108
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109--show-cdup::
110 When the command is invoked from a subdirectory, show the
111 path of the top-level directory relative to the current
112 directory (typically a sequence of "../", or an empty string).
113
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114--git-dir::
115 Show `$GIT_DIR` if defined else show the path to the .git directory.
116
c9bf7be2 117--is-inside-git-dir::
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118 When the current working directory is below the repository
119 directory print "true", otherwise "false".
120
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121--is-inside-work-tree::
122 When the current working directory is inside the work tree of the
123 repository print "true", otherwise "false".
124
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125--is-bare-repository::
126 When the repository is bare print "true", otherwise "false".
c9bf7be2 127
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128--short::
129--short=number::
735d80b3 130 Instead of outputting the full SHA1 values of object names try to
abda1ef5 131 abbreviate them to a shorter unique name. When no length is specified
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132 7 is used. The minimum length is 4.
133
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134--since=datestring::
135--after=datestring::
483bc4f0 136 Parse the date string, and output the corresponding
ba020ef5 137 --max-age= parameter for 'git-rev-list'.
a3114b34 138
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139--until=datestring::
140--before=datestring::
483bc4f0 141 Parse the date string, and output the corresponding
ba020ef5 142 --min-age= parameter for 'git-rev-list'.
a3114b34 143
7fc9d69f 144<args>...::
5077fa9c 145 Flags and parameters to be parsed.
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146
147
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148SPECIFYING REVISIONS
149--------------------
150
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151A revision parameter typically, but not necessarily, names a
152commit object. They use what is called an 'extended SHA1'
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153syntax. Here are various ways to spell object names. The
154ones listed near the end of this list are to name trees and
155blobs contained in a commit.
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156
157* The full SHA1 object name (40-byte hexadecimal string), or
158 a substring of such that is unique within the repository.
159 E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
160 name the same commit object if there are no other object in
161 your repository whose object name starts with dae86e.
162
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163* An output from 'git-describe'; i.e. a closest tag, optionally
164 followed by a dash and a number of commits, followed by a dash, a
165 `g`, and an abbreviated object name.
6b09c788 166
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167* A symbolic ref name. E.g. 'master' typically means the commit
168 object referenced by $GIT_DIR/refs/heads/master. If you
169 happen to have both heads/master and tags/master, you can
72e9340c 170 explicitly say 'heads/master' to tell git which one you mean.
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171 When ambiguous, a `<name>` is disambiguated by taking the
172 first match in the following rules:
3a45f625 173
0ac30568 174 . if `$GIT_DIR/<name>` exists, that is what you mean (this is usually
fd11ae0b 175 useful only for `HEAD`, `FETCH_HEAD`, `ORIG_HEAD` and `MERGE_HEAD`);
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176
177 . otherwise, `$GIT_DIR/refs/<name>` if exists;
178
179 . otherwise, `$GIT_DIR/refs/tags/<name>` if exists;
180
181 . otherwise, `$GIT_DIR/refs/heads/<name>` if exists;
182
183 . otherwise, `$GIT_DIR/refs/remotes/<name>` if exists;
184
185 . otherwise, `$GIT_DIR/refs/remotes/<name>/HEAD` if exists.
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186+
187HEAD names the commit your changes in the working tree is based on.
188FETCH_HEAD records the branch you fetched from a remote repository
189with your last 'git-fetch' invocation.
190ORIG_HEAD is created by commands that moves your HEAD in a drastic
191way, to record the position of the HEAD before their operation, so that
192you can change the tip of the branch back to the state before you ran
193them easily.
194MERGE_HEAD records the commit(s) you are merging into your branch
195when you run 'git-merge'.
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196
197* A ref followed by the suffix '@' with a date specification
198 enclosed in a brace
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199 pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1
200 second ago\}' or '\{1979-02-26 18:30:00\}') to specify the value
201 of the ref at a prior point in time. This suffix may only be
202 used immediately following a ref name and the ref must have an
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203 existing log ($GIT_DIR/logs/<ref>). Note that this looks up the state
204 of your *local* ref at a given time; e.g., what was in your local
205 `master` branch last week. If you want to look at commits made during
206 certain times, see `--since` and `--until`.
d556fae2 207
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208* A ref followed by the suffix '@' with an ordinal specification
209 enclosed in a brace pair (e.g. '\{1\}', '\{15\}') to specify
210 the n-th prior value of that ref. For example 'master@\{1\}'
211 is the immediate prior value of 'master' while 'master@\{5\}'
212 is the 5th prior value of 'master'. This suffix may only be used
213 immediately following a ref name and the ref must have an existing
214 log ($GIT_DIR/logs/<ref>).
215
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216* You can use the '@' construct with an empty ref part to get at a
217 reflog of the current branch. For example, if you are on the
218 branch 'blabla', then '@\{1\}' means the same as 'blabla@\{1\}'.
219
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220* The special construct '@\{-<n>\}' means the <n>th branch checked out
221 before the current one.
222
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223* A suffix '{caret}' to a revision parameter means the first parent of
224 that commit object. '{caret}<n>' means the <n>th parent (i.e.
225 'rev{caret}'
226 is equivalent to 'rev{caret}1'). As a special rule,
227 'rev{caret}0' means the commit itself and is used when 'rev' is the
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228 object name of a tag object that refers to a commit object.
229
54bd2558 230* A suffix '{tilde}<n>' to a revision parameter means the commit
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231 object that is the <n>th generation grand-parent of the named
232 commit object, following only the first parent. I.e. rev~3 is
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233 equivalent to rev{caret}{caret}{caret} which is equivalent to
234 rev{caret}1{caret}1{caret}1. See below for a illustration of
235 the usage of this form.
3a45f625 236
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237* A suffix '{caret}' followed by an object type name enclosed in
238 brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
239 could be a tag, and dereference the tag recursively until an
240 object of that type is found or the object cannot be
241 dereferenced anymore (in which case, barf). `rev{caret}0`
242 introduced earlier is a short-hand for `rev{caret}\{commit\}`.
243
244* A suffix '{caret}' followed by an empty brace pair
245 (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag,
246 and dereference the tag recursively until a non-tag object is
247 found.
248
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249* A colon, followed by a slash, followed by a text: this names
250 a commit whose commit message starts with the specified text.
251 This name returns the youngest matching commit which is
252 reachable from any ref. If the commit message starts with a
253 '!', you have to repeat that; the special sequence ':/!',
254 followed by something else than '!' is reserved for now.
255
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256* A suffix ':' followed by a path; this names the blob or tree
257 at the given path in the tree-ish object named by the part
258 before the colon.
259
260* A colon, optionally followed by a stage number (0 to 3) and a
261 colon, followed by a path; this names a blob object in the
262 index at the given path. Missing stage number (and the colon
a5d86f74 263 that follows it) names a stage 0 entry. During a merge, stage
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264 1 is the common ancestor, stage 2 is the target branch's version
265 (typically the current branch), and stage 3 is the version from
266 the branch being merged.
6b09c788 267
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268Here is an illustration, by Jon Loeliger. Both commit nodes B
269and C are parents of commit node A. Parent commits are ordered
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270left-to-right.
271
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272........................................
273G H I J
274 \ / \ /
275 D E F
276 \ | / \
277 \ | / |
278 \|/ |
279 B C
280 \ /
281 \ /
282 A
283........................................
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284
285 A = = A^0
286 B = A^ = A^1 = A~1
287 C = A^2 = A^2
288 D = A^^ = A^1^1 = A~2
289 E = B^2 = A^^2
290 F = B^3 = A^^3
291 G = A^^^ = A^1^1^1 = A~3
292 H = D^2 = B^^2 = A^^^2 = A~2^2
293 I = F^ = B^3^ = A^^3^
294 J = F^2 = B^3^2 = A^^3^2
295
3a45f625 296
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297SPECIFYING RANGES
298-----------------
299
ba020ef5 300History traversing commands such as 'git-log' operate on a set
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301of commits, not just a single commit. To these commands,
302specifying a single revision with the notation described in the
303previous section means the set of commits reachable from that
304commit, following the commit ancestry chain.
305
306To exclude commits reachable from a commit, a prefix `{caret}`
dcb11263 307notation is used. E.g. `{caret}r1 r2` means commits reachable
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308from `r2` but exclude the ones reachable from `r1`.
309
310This set operation appears so often that there is a shorthand
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311for it. When you have two commits `r1` and `r2` (named according
312to the syntax explained in SPECIFYING REVISIONS above), you can ask
313for commits that are reachable from r2 excluding those that are reachable
dcb11263 314from r1 by `{caret}r1 r2` and it can be written as `r1..r2`.
be4c7014 315
dcb11263 316A similar notation `r1\...r2` is called symmetric difference
be4c7014 317of `r1` and `r2` and is defined as
dcb11263 318`r1 r2 --not $(git merge-base --all r1 r2)`.
e18ee576 319It is the set of commits that are reachable from either one of
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320`r1` or `r2` but not from both.
321
62476c8e 322Two other shorthands for naming a set that is formed by a commit
faf466ff 323and its parent commits exist. The `r1{caret}@` notation means all
62476c8e 324parents of `r1`. `r1{caret}!` includes commit `r1` but excludes
faf466ff 325all of its parents.
62476c8e 326
a5d86f74 327Here are a handful of examples:
be4c7014 328
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329 D G H D
330 D F G H I J D F
331 ^G D H D
332 ^D B E I J F B
333 B...C G H D E B C
334 ^D B C E I J F B C
335 C^@ I J F
336 F^! D G H D F
be4c7014 337
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338PARSEOPT
339--------
340
ba020ef5 341In `--parseopt` mode, 'git-rev-parse' helps massaging options to bring to shell
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342scripts the same facilities C builtins have. It works as an option normalizer
343(e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
344
345It takes on the standard input the specification of the options to parse and
346understand, and echoes on the standard output a line suitable for `sh(1)` `eval`
347to replace the arguments with normalized ones. In case of error, it outputs
348usage on the standard error stream, and exits with code 129.
349
350Input Format
351~~~~~~~~~~~~
352
ba020ef5 353'git-rev-parse --parseopt' input format is fully text based. It has two parts,
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354separated by a line that contains only `--`. The lines before the separator
355(should be more than one) are used for the usage.
356The lines after the separator describe the options.
357
358Each line of options has this format:
359
360------------
ff962a3f 361<opt_spec><flags>* SP+ help LF
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362------------
363
364`<opt_spec>`::
365 its format is the short option character, then the long option name
366 separated by a comma. Both parts are not required, though at least one
367 is necessary. `h,help`, `dry-run` and `f` are all three correct
368 `<opt_spec>`.
369
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370`<flags>`::
371 `<flags>` are of `*`, `=`, `?` or `!`.
372 * Use `=` if the option takes an argument.
373
374 * Use `?` to mean that the option is optional (though its use is discouraged).
375
376 * Use `*` to mean that this option should not be listed in the usage
377 generated for the `-h` argument. It's shown for `--help-all` as
a5af0e2c 378 documented in linkgit:gitcli[7].
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379
380 * Use `!` to not make the corresponding negated long option available.
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381
382The remainder of the line, after stripping the spaces, is used
383as the help associated to the option.
384
385Blank lines are ignored, and lines that don't match this specification are used
386as option group headers (start the line with a space to create such
387lines on purpose).
388
389Example
390~~~~~~~
391
392------------
393OPTS_SPEC="\
394some-command [options] <args>...
395
396some-command does foo and bar!
397--
398h,help show the help
399
400foo some nifty option --foo
401bar= some cool option --bar with an argument
402
403 An option group Header
404C? option C with an optional argument"
405
b1889c36 406eval `echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?`
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407------------
408
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409EXAMPLES
410--------
411
412* Print the object name of the current commit:
413+
414------------
415$ git rev-parse --verify HEAD
416------------
417
418* Print the commit object name from the revision in the $REV shell variable:
419+
420------------
421$ git rev-parse --verify $REV
422------------
423+
424This will error out if $REV is empty or not a valid revision.
425
426* Same as above:
427+
428------------
429$ git rev-parse --default master --verify $REV
430------------
431+
432but if $REV is empty, the commit object name from master will be printed.
433
21d47835 434
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435Author
436------
21d47835 437Written by Linus Torvalds <torvalds@osdl.org> .
59eb68aa 438Junio C Hamano <gitster@pobox.com> and Pierre Habouzit <madcoder@debian.org>
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439
440Documentation
441--------------
442Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
443
444GIT
445---
9e1f0a85 446Part of the linkgit:git[1] suite