Documentation/git-parse-remote.txt: we deal with config vars as well
[git/git.git] / Documentation / git-rev-parse.txt
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1git-rev-parse(1)
2================
3
4NAME
5----
6git-rev-parse - Pick out and massage parameters
7
8
9SYNOPSIS
10--------
11'git-rev-parse' [ --option ] <args>...
12
13DESCRIPTION
14-----------
15
16Many git porcelainish commands take mixture of flags
17(i.e. parameters that begin with a dash '-') and parameters
18meant for underlying `git-rev-list` command they use internally
19and flags and parameters for other commands they use as the
20downstream of `git-rev-list`. This command is used to
21distinguish between them.
22
23
24OPTIONS
25-------
26--revs-only::
27 Do not output flags and parameters not meant for
28 `git-rev-list` command.
29
30--no-revs::
31 Do not output flags and parameters meant for
32 `git-rev-list` command.
33
34--flags::
35 Do not output non-flag parameters.
36
37--no-flags::
38 Do not output flag parameters.
39
40--default <arg>::
41 If there is no parameter given by the user, use `<arg>`
42 instead.
43
44--verify::
45 The parameter given must be usable as a single, valid
46 object name. Otherwise barf and abort.
47
48--sq::
49 Usually the output is made one line per flag and
50 parameter. This option makes output a single line,
51 properly quoted for consumption by shell. Useful when
52 you expect your parameter to contain whitespaces and
53 newlines (e.g. when using pickaxe `-S` with
54 `git-diff-\*`).
55
56--not::
57 When showing object names, prefix them with '{caret}' and
58 strip '{caret}' prefix from the object names that already have
59 one.
60
61--symbolic::
62 Usually the object names are output in SHA1 form (with
63 possible '{caret}' prefix); this option makes them output in a
64 form as close to the original input as possible.
65
66
67--all::
68 Show all refs found in `$GIT_DIR/refs`.
69
70--branches::
71 Show branch refs found in `$GIT_DIR/refs/heads`.
72
73--tags::
74 Show tag refs found in `$GIT_DIR/refs/tags`.
75
76--remotes::
77 Show tag refs found in `$GIT_DIR/refs/remotes`.
78
79--show-prefix::
80 When the command is invoked from a subdirectory, show the
81 path of the current directory relative to the top-level
82 directory.
83
84--show-cdup::
85 When the command is invoked from a subdirectory, show the
86 path of the top-level directory relative to the current
87 directory (typically a sequence of "../", or an empty string).
88
89--git-dir::
90 Show `$GIT_DIR` if defined else show the path to the .git directory.
91
92--short, --short=number::
93 Instead of outputting the full SHA1 values of object names try to
94 abbreviate them to a shorter unique name. When no length is specified
95 7 is used. The minimum length is 4.
96
97--since=datestring, --after=datestring::
98 Parses the date string, and outputs corresponding
99 --max-age= parameter for git-rev-list command.
100
101--until=datestring, --before=datestring::
102 Parses the date string, and outputs corresponding
103 --min-age= parameter for git-rev-list command.
104
105<args>...::
106 Flags and parameters to be parsed.
107
108
109SPECIFYING REVISIONS
110--------------------
111
112A revision parameter typically, but not necessarily, names a
113commit object. They use what is called an 'extended SHA1'
114syntax. Here are various ways to spell object names. The
115ones listed near the end of this list are to name trees and
116blobs contained in a commit.
117
118* The full SHA1 object name (40-byte hexadecimal string), or
119 a substring of such that is unique within the repository.
120 E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
121 name the same commit object if there are no other object in
122 your repository whose object name starts with dae86e.
123
124* An output from `git-describe`; i.e. a closest tag, followed by a
125 dash, a `g`, and an abbreviated object name.
126
127* A symbolic ref name. E.g. 'master' typically means the commit
128 object referenced by $GIT_DIR/refs/heads/master. If you
129 happen to have both heads/master and tags/master, you can
130 explicitly say 'heads/master' to tell git which one you mean.
131 When ambiguous, a `<name>` is disambiguated by taking the
132 first match in the following rules:
133
134 . if `$GIT_DIR/<name>` exists, that is what you mean (this is usually
135 useful only for `HEAD`, `FETCH_HEAD` and `MERGE_HEAD`);
136
137 . otherwise, `$GIT_DIR/refs/<name>` if exists;
138
139 . otherwise, `$GIT_DIR/refs/tags/<name>` if exists;
140
141 . otherwise, `$GIT_DIR/refs/heads/<name>` if exists;
142
143 . otherwise, `$GIT_DIR/refs/remotes/<name>` if exists;
144
145 . otherwise, `$GIT_DIR/refs/remotes/<name>/HEAD` if exists.
146
147* A ref followed by the suffix '@' with a date specification
148 enclosed in a brace
149 pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1
150 second ago\}' or '\{1979-02-26 18:30:00\}') to specify the value
151 of the ref at a prior point in time. This suffix may only be
152 used immediately following a ref name and the ref must have an
153 existing log ($GIT_DIR/logs/<ref>).
154
155* A suffix '{caret}' to a revision parameter means the first parent of
156 that commit object. '{caret}<n>' means the <n>th parent (i.e.
157 'rev{caret}'
158 is equivalent to 'rev{caret}1'). As a special rule,
159 'rev{caret}0' means the commit itself and is used when 'rev' is the
160 object name of a tag object that refers to a commit object.
161
162* A suffix '{tilde}<n>' to a revision parameter means the commit
163 object that is the <n>th generation grand-parent of the named
164 commit object, following only the first parent. I.e. rev~3 is
165 equivalent to rev{caret}{caret}{caret} which is equivalent to
166 rev{caret}1{caret}1{caret}1. See below for a illustration of
167 the usage of this form.
168
169* A suffix '{caret}' followed by an object type name enclosed in
170 brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
171 could be a tag, and dereference the tag recursively until an
172 object of that type is found or the object cannot be
173 dereferenced anymore (in which case, barf). `rev{caret}0`
174 introduced earlier is a short-hand for `rev{caret}\{commit\}`.
175
176* A suffix '{caret}' followed by an empty brace pair
177 (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag,
178 and dereference the tag recursively until a non-tag object is
179 found.
180
181* A suffix ':' followed by a path; this names the blob or tree
182 at the given path in the tree-ish object named by the part
183 before the colon.
184
185* A colon, optionally followed by a stage number (0 to 3) and a
186 colon, followed by a path; this names a blob object in the
187 index at the given path. Missing stage number (and the colon
188 that follows it) names an stage 0 entry.
189
190Here is an illustration, by Jon Loeliger. Both node B and C are
191a commit parents of commit node A. Parent commits are ordered
192left-to-right.
193
194 G H I J
195 \ / \ /
196 D E F
197 \ | / \
198 \ | / |
199 \|/ |
200 B C
201 \ /
202 \ /
203 A
204
205 A = = A^0
206 B = A^ = A^1 = A~1
207 C = A^2 = A^2
208 D = A^^ = A^1^1 = A~2
209 E = B^2 = A^^2
210 F = B^3 = A^^3
211 G = A^^^ = A^1^1^1 = A~3
212 H = D^2 = B^^2 = A^^^2 = A~2^2
213 I = F^ = B^3^ = A^^3^
214 J = F^2 = B^3^2 = A^^3^2
215
216
217SPECIFYING RANGES
218-----------------
219
220History traversing commands such as `git-log` operate on a set
221of commits, not just a single commit. To these commands,
222specifying a single revision with the notation described in the
223previous section means the set of commits reachable from that
224commit, following the commit ancestry chain.
225
226To exclude commits reachable from a commit, a prefix `{caret}`
227notation is used. E.g. "`{caret}r1 r2`" means commits reachable
228from `r2` but exclude the ones reachable from `r1`.
229
230This set operation appears so often that there is a shorthand
231for it. "`r1..r2`" is equivalent to "`{caret}r1 r2`". It is
232the difference of two sets (subtract the set of commits
233reachable from `r1` from the set of commits reachable from
234`r2`).
235
236A similar notation "`r1\...r2`" is called symmetric difference
237of `r1` and `r2` and is defined as
238"`r1 r2 --not $(git-merge-base --all r1 r2)`".
239It it the set of commits that are reachable from either one of
240`r1` or `r2` but not from both.
241
242Two other shorthands for naming a set that is formed by a commit
243and its parent commits exists. `r1{caret}@` notation means all
244parents of `r1`. `r1{caret}!` includes commit `r1` but excludes
245its all parents.
246
247Here are a handful examples:
248
249 D A B D
250 D F A B C D F
251 ^A G B D
252 ^A F B C F
253 G...I C D F G I
254 ^B G I C D F G I
255 F^@ A B C
256 F^! H D F H
257
258Author
259------
260Written by Linus Torvalds <torvalds@osdl.org> and
261Junio C Hamano <junkio@cox.net>
262
263Documentation
264--------------
265Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
266
267GIT
268---
269Part of the gitlink:git[7] suite
270