1 git-rev-parse(1)
2 ================
4 NAME
5 ----
6 git-rev-parse - Pick out and massage parameters
9 SYNOPSIS
10 --------
11 'git rev-parse' [ --option ] <args>...
13 DESCRIPTION
14 -----------
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.
24 OPTIONS
25 -------
26 --parseopt::
27 Use 'git rev-parse' in option parsing mode (see PARSEOPT section below).
29 --keep-dashdash::
30 Only meaningful in `--parseopt` mode. Tells the option parser to echo
31 out the first `--` met instead of skipping it.
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.
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.
43 --revs-only::
44 Do not output flags and parameters not meant for
45 'git rev-list' command.
47 --no-revs::
48 Do not output flags and parameters meant for
49 'git rev-list' command.
51 --flags::
52 Do not output non-flag parameters.
54 --no-flags::
55 Do not output flag parameters.
57 --default <arg>::
58 If there is no parameter given by the user, use `<arg>`
59 instead.
61 --verify::
62 The parameter given must be usable as a single, valid
63 object name. Otherwise barf and abort.
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.
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.
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.
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.
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").
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.
103 --all::
104 Show all refs found in `$GIT_DIR/refs`.
106 --branches::
107 Show branch refs found in `$GIT_DIR/refs/heads`.
109 --tags::
110 Show tag refs found in `$GIT_DIR/refs/tags`.
112 --remotes::
113 Show tag refs found in `$GIT_DIR/refs/remotes`.
115 --show-toplevel::
116 Show the absolute path of the top-level directory.
118 --show-prefix::
119 When the command is invoked from a subdirectory, show the
120 path of the current directory relative to the top-level
121 directory.
123 --show-cdup::
124 When the command is invoked from a subdirectory, show the
125 path of the top-level directory relative to the current
126 directory (typically a sequence of "../", or an empty string).
128 --git-dir::
129 Show `$GIT_DIR` if defined else show the path to the .git directory.
131 --is-inside-git-dir::
132 When the current working directory is below the repository
133 directory print "true", otherwise "false".
135 --is-inside-work-tree::
136 When the current working directory is inside the work tree of the
137 repository print "true", otherwise "false".
139 --is-bare-repository::
140 When the repository is bare print "true", otherwise "false".
142 --short::
143 --short=number::
144 Instead of outputting the full SHA1 values of object names try to
145 abbreviate them to a shorter unique name. When no length is specified
146 7 is used. The minimum length is 4.
148 --since=datestring::
149 --after=datestring::
150 Parse the date string, and output the corresponding
151 --max-age= parameter for 'git rev-list'.
153 --until=datestring::
154 --before=datestring::
155 Parse the date string, and output the corresponding
156 --min-age= parameter for 'git rev-list'.
158 <args>...::
159 Flags and parameters to be parsed.
162 SPECIFYING REVISIONS
163 --------------------
165 A revision parameter typically, but not necessarily, names a
166 commit object. They use what is called an 'extended SHA1'
167 syntax. Here are various ways to spell object names. The
168 ones listed near the end of this list are to name trees and
169 blobs contained in a commit.
171 * The full SHA1 object name (40-byte hexadecimal string), or
172 a substring of such that is unique within the repository.
173 E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
174 name the same commit object if there are no other object in
175 your repository whose object name starts with dae86e.
177 * An output from 'git describe'; i.e. a closest tag, optionally
178 followed by a dash and a number of commits, followed by a dash, a
179 `g`, and an abbreviated object name.
181 * A symbolic ref name. E.g. 'master' typically means the commit
182 object referenced by $GIT_DIR/refs/heads/master. If you
183 happen to have both heads/master and tags/master, you can
184 explicitly say 'heads/master' to tell git which one you mean.
185 When ambiguous, a `<name>` is disambiguated by taking the
186 first match in the following rules:
188 . if `$GIT_DIR/<name>` exists, that is what you mean (this is usually
189 useful only for `HEAD`, `FETCH_HEAD`, `ORIG_HEAD` and `MERGE_HEAD`);
191 . otherwise, `$GIT_DIR/refs/<name>` if exists;
193 . otherwise, `$GIT_DIR/refs/tags/<name>` if exists;
195 . otherwise, `$GIT_DIR/refs/heads/<name>` if exists;
197 . otherwise, `$GIT_DIR/refs/remotes/<name>` if exists;
199 . otherwise, `$GIT_DIR/refs/remotes/<name>/HEAD` if exists.
200 +
201 HEAD names the commit your changes in the working tree is based on.
202 FETCH_HEAD records the branch you fetched from a remote repository
203 with your last 'git fetch' invocation.
204 ORIG_HEAD is created by commands that moves your HEAD in a drastic
205 way, to record the position of the HEAD before their operation, so that
206 you can change the tip of the branch back to the state before you ran
207 them easily.
208 MERGE_HEAD records the commit(s) you are merging into your branch
209 when you run 'git merge'.
211 * A ref followed by the suffix '@' with a date specification
212 enclosed in a brace
213 pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1
214 second ago\}' or '\{1979-02-26 18:30:00\}') to specify the value
215 of the ref at a prior point in time. This suffix may only be
216 used immediately following a ref name and the ref must have an
217 existing log ($GIT_DIR/logs/<ref>). Note that this looks up the state
218 of your *local* ref at a given time; e.g., what was in your local
219 `master` branch last week. If you want to look at commits made during
220 certain times, see `--since` and `--until`.
222 * A ref followed by the suffix '@' with an ordinal specification
223 enclosed in a brace pair (e.g. '\{1\}', '\{15\}') to specify
224 the n-th prior value of that ref. For example 'master@\{1\}'
225 is the immediate prior value of 'master' while 'master@\{5\}'
226 is the 5th prior value of 'master'. This suffix may only be used
227 immediately following a ref name and the ref must have an existing
228 log ($GIT_DIR/logs/<ref>).
230 * You can use the '@' construct with an empty ref part to get at a
231 reflog of the current branch. For example, if you are on the
232 branch 'blabla', then '@\{1\}' means the same as 'blabla@\{1\}'.
234 * The special construct '@\{-<n>\}' means the <n>th branch checked out
235 before the current one.
237 * The suffix '@{upstream}' to a ref (short form 'ref@{u}') refers to
238 the branch the ref is set to build on top of. Missing ref defaults
239 to the current branch.
241 * A suffix '{caret}' to a revision parameter means the first parent of
242 that commit object. '{caret}<n>' means the <n>th parent (i.e.
243 'rev{caret}'
244 is equivalent to 'rev{caret}1'). As a special rule,
245 'rev{caret}0' means the commit itself and is used when 'rev' is the
246 object name of a tag object that refers to a commit object.
248 * A suffix '{tilde}<n>' to a revision parameter means the commit
249 object that is the <n>th generation grand-parent of the named
250 commit object, following only the first parent. I.e. rev~3 is
251 equivalent to rev{caret}{caret}{caret} which is equivalent to
252 rev{caret}1{caret}1{caret}1. See below for a illustration of
253 the usage of this form.
255 * A suffix '{caret}' followed by an object type name enclosed in
256 brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
257 could be a tag, and dereference the tag recursively until an
258 object of that type is found or the object cannot be
259 dereferenced anymore (in which case, barf). `rev{caret}0`
260 introduced earlier is a short-hand for `rev{caret}\{commit\}`.
262 * A suffix '{caret}' followed by an empty brace pair
263 (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag,
264 and dereference the tag recursively until a non-tag object is
265 found.
267 * A colon, followed by a slash, followed by a text: this names
268 a commit whose commit message starts with the specified text.
269 This name returns the youngest matching commit which is
270 reachable from any ref. If the commit message starts with a
271 '!', you have to repeat that; the special sequence ':/!',
272 followed by something else than '!' is reserved for now.
274 * A suffix ':' followed by a path; this names the blob or tree
275 at the given path in the tree-ish object named by the part
276 before the colon.
278 * A colon, optionally followed by a stage number (0 to 3) and a
279 colon, followed by a path; this names a blob object in the
280 index at the given path. Missing stage number (and the colon
281 that follows it) names a stage 0 entry. During a merge, stage
282 1 is the common ancestor, stage 2 is the target branch's version
283 (typically the current branch), and stage 3 is the version from
284 the branch being merged.
286 Here is an illustration, by Jon Loeliger. Both commit nodes B
287 and C are parents of commit node A. Parent commits are ordered
288 left-to-right.
290 ........................................
291 G H I J
292 \ / \ /
293 D E F
294 \ | / \
295 \ | / |
296 \|/ |
297 B C
298 \ /
299 \ /
300 A
301 ........................................
303 A = = A^0
304 B = A^ = A^1 = A~1
305 C = A^2 = A^2
306 D = A^^ = A^1^1 = A~2
307 E = B^2 = A^^2
308 F = B^3 = A^^3
309 G = A^^^ = A^1^1^1 = A~3
310 H = D^2 = B^^2 = A^^^2 = A~2^2
311 I = F^ = B^3^ = A^^3^
312 J = F^2 = B^3^2 = A^^3^2
315 SPECIFYING RANGES
316 -----------------
318 History traversing commands such as 'git log' operate on a set
319 of commits, not just a single commit. To these commands,
320 specifying a single revision with the notation described in the
321 previous section means the set of commits reachable from that
322 commit, following the commit ancestry chain.
324 To exclude commits reachable from a commit, a prefix `{caret}`
325 notation is used. E.g. `{caret}r1 r2` means commits reachable
326 from `r2` but exclude the ones reachable from `r1`.
328 This set operation appears so often that there is a shorthand
329 for it. When you have two commits `r1` and `r2` (named according
330 to the syntax explained in SPECIFYING REVISIONS above), you can ask
331 for commits that are reachable from r2 excluding those that are reachable
332 from r1 by `{caret}r1 r2` and it can be written as `r1..r2`.
334 A similar notation `r1\...r2` is called symmetric difference
335 of `r1` and `r2` and is defined as
336 `r1 r2 --not $(git merge-base --all r1 r2)`.
337 It is the set of commits that are reachable from either one of
338 `r1` or `r2` but not from both.
340 Two other shorthands for naming a set that is formed by a commit
341 and its parent commits exist. The `r1{caret}@` notation means all
342 parents of `r1`. `r1{caret}!` includes commit `r1` but excludes
343 all of its parents.
345 Here are a handful of examples:
347 D G H D
348 D F G H I J D F
349 ^G D H D
350 ^D B E I J F B
351 B...C G H D E B C
352 ^D B C E I J F B C
353 C^@ I J F
354 F^! D G H D F
356 PARSEOPT
357 --------
359 In `--parseopt` mode, 'git rev-parse' helps massaging options to bring to shell
360 scripts the same facilities C builtins have. It works as an option normalizer
361 (e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
363 It takes on the standard input the specification of the options to parse and
364 understand, and echoes on the standard output a line suitable for `sh(1)` `eval`
365 to replace the arguments with normalized ones. In case of error, it outputs
366 usage on the standard error stream, and exits with code 129.
368 Input Format
369 ~~~~~~~~~~~~
371 'git rev-parse --parseopt' input format is fully text based. It has two parts,
372 separated by a line that contains only `--`. The lines before the separator
373 (should be more than one) are used for the usage.
374 The lines after the separator describe the options.
376 Each line of options has this format:
378 ------------
379 <opt_spec><flags>* SP+ help LF
380 ------------
382 `<opt_spec>`::
383 its format is the short option character, then the long option name
384 separated by a comma. Both parts are not required, though at least one
385 is necessary. `h,help`, `dry-run` and `f` are all three correct
386 `<opt_spec>`.
388 `<flags>`::
389 `<flags>` are of `*`, `=`, `?` or `!`.
390 * Use `=` if the option takes an argument.
392 * Use `?` to mean that the option is optional (though its use is discouraged).
394 * Use `*` to mean that this option should not be listed in the usage
395 generated for the `-h` argument. It's shown for `--help-all` as
396 documented in linkgit:gitcli[7].
398 * Use `!` to not make the corresponding negated long option available.
400 The remainder of the line, after stripping the spaces, is used
401 as the help associated to the option.
403 Blank lines are ignored, and lines that don't match this specification are used
404 as option group headers (start the line with a space to create such
405 lines on purpose).
407 Example
408 ~~~~~~~
410 ------------
411 OPTS_SPEC="\
412 some-command [options] <args>...
414 some-command does foo and bar!
415 --
416 h,help show the help
418 foo some nifty option --foo
419 bar= some cool option --bar with an argument
421 An option group Header
422 C? option C with an optional argument"
424 eval `echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?`
425 ------------
427 SQ-QUOTE
428 --------
430 In `--sq-quote` mode, 'git rev-parse' echoes on the standard output a
431 single line suitable for `sh(1)` `eval`. This line is made by
432 normalizing the arguments following `--sq-quote`. Nothing other than
433 quoting the arguments is done.
435 If you want command input to still be interpreted as usual by
436 'git rev-parse' before the output is shell quoted, see the `--sq`
437 option.
439 Example
440 ~~~~~~~
442 ------------
443 $ cat >your-git-script.sh <<\EOF
444 #!/bin/sh
445 args=$(git rev-parse --sq-quote "$@") # quote user-supplied arguments
446 command="git frotz -n24 $args" # and use it inside a handcrafted
447 # command line
448 eval "$command"
449 EOF
451 $ sh your-git-script.sh "a b'c"
452 ------------
454 EXAMPLES
455 --------
457 * Print the object name of the current commit:
458 +
459 ------------
460 $ git rev-parse --verify HEAD
461 ------------
463 * Print the commit object name from the revision in the $REV shell variable:
464 +
465 ------------
466 $ git rev-parse --verify $REV
467 ------------
468 +
469 This will error out if $REV is empty or not a valid revision.
471 * Same as above:
472 +
473 ------------
474 $ git rev-parse --default master --verify $REV
475 ------------
476 +
477 but if $REV is empty, the commit object name from master will be printed.
480 Author
481 ------
482 Written by Linus Torvalds <torvalds@osdl.org> .
483 Junio C Hamano <gitster@pobox.com> and Pierre Habouzit <madcoder@debian.org>
485 Documentation
486 --------------
487 Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
489 GIT
490 ---
491 Part of the linkgit:git[1] suite