Log ref updates to logs/refs/<ref>
[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--------
11'git-rev-parse' [ --option ] <args>...
12
13DESCRIPTION
14-----------
5077fa9c
JH
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.
7fc9d69f
JH
22
23
24OPTIONS
25-------
5077fa9c
JH
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::
babfaba2
JF
57 When showing object names, prefix them with '{caret}' and
58 strip '{caret}' prefix from the object names that already have
5077fa9c
JH
59 one.
60
61--symbolic::
62 Usually the object names are output in SHA1 form (with
babfaba2 63 possible '{caret}' prefix); this option makes them output in a
5077fa9c
JH
64 form as close to the original input as possible.
65
66
67--all::
68 Show all refs found in `$GIT_DIR/refs`.
69
a62be77f
SE
70--branches::
71 Show branch refs found in `$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
5077fa9c 79--show-prefix::
5f94c730 80 When the command is invoked from a subdirectory, show the
5077fa9c
JH
81 path of the current directory relative to the top-level
82 directory.
7fc9d69f 83
5f94c730
JH
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
735d80b3
JF
89--git-dir::
90 Show `$GIT_DIR` if defined else show the path to the .git directory.
91
5102349c 92--short, --short=number::
735d80b3
JF
93 Instead of outputting the full SHA1 values of object names try to
94 abbriviate them to a shorter unique name. When no length is specified
95 7 is used. The minimum length is 4.
96
a3114b34
JH
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
7fc9d69f 105<args>...::
5077fa9c 106 Flags and parameters to be parsed.
7fc9d69f
JH
107
108
3a45f625
JH
109SPECIFYING REVISIONS
110--------------------
111
622ef9df
JH
112A revision parameter typically, but not necessarily, names a
113commit object. They use what is called an 'extended SHA1'
114syntax.
3a45f625
JH
115
116* The full SHA1 object name (40-byte hexadecimal string), or
117 a substring of such that is unique within the repository.
118 E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
119 name the same commit object if there are no other object in
120 your repository whose object name starts with dae86e.
121
122* A symbolic ref name. E.g. 'master' typically means the commit
123 object referenced by $GIT_DIR/refs/heads/master. If you
124 happen to have both heads/master and tags/master, you can
72e9340c 125 explicitly say 'heads/master' to tell git which one you mean.
3a45f625 126
babfaba2
JF
127* A suffix '{caret}' to a revision parameter means the first parent of
128 that commit object. '{caret}<n>' means the <n>th parent (i.e.
129 'rev{caret}'
130 is equivalent to 'rev{caret}1'). As a special rule,
131 'rev{caret}0' means the commit itself and is used when 'rev' is the
3a45f625
JH
132 object name of a tag object that refers to a commit object.
133
134* A suffix '~<n>' to a revision parameter means the commit
135 object that is the <n>th generation grand-parent of the named
136 commit object, following only the first parent. I.e. rev~3 is
babfaba2
JF
137 equivalent to rev{caret}{caret}{caret} which is equivalent to\
138 rev{caret}1{caret}1{caret}1.
3a45f625 139
622ef9df
JH
140* A suffix '{caret}' followed by an object type name enclosed in
141 brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
142 could be a tag, and dereference the tag recursively until an
143 object of that type is found or the object cannot be
144 dereferenced anymore (in which case, barf). `rev{caret}0`
145 introduced earlier is a short-hand for `rev{caret}\{commit\}`.
146
147* A suffix '{caret}' followed by an empty brace pair
148 (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag,
149 and dereference the tag recursively until a non-tag object is
150 found.
151
babfaba2 152'git-rev-parse' also accepts a prefix '{caret}' to revision parameter,
3a45f625
JH
153which is passed to 'git-rev-list'. Two revision parameters
154concatenated with '..' is a short-hand for writing a range
babfaba2 155between them. I.e. 'r1..r2' is equivalent to saying '{caret}r1 r2'
3a45f625 156
2be8fd08
JH
157Here is an illustration, by Jon Loeliger. Both node B and C are
158a commit parents of commit node A. Parent commits are ordered
159left-to-right.
160
161 G H I J
162 \ / \ /
163 D E F
164 \ | /
165 \ | /
166 \|/
167 B C
168 \ /
169 \ /
170 A
171
172 A = = A^0
173 B = A^ = A^1 = A~1
174 C = A^2 = A^2
175 D = A^^ = A^1^1 = A~2
176 E = B^2 = A^^2
177 F = B^3 = A^^3
178 G = A^^^ = A^1^1^1 = A~3
179 H = D^2 = B^^2 = A^^^2 = A~2^2
180 I = F^ = B^3^ = A^^3^
181 J = F^2 = B^3^2 = A^^3^2
182
3a45f625 183
7fc9d69f
JH
184Author
185------
5077fa9c
JH
186Written by Linus Torvalds <torvalds@osdl.org> and
187Junio C Hamano <junkio@cox.net>
7fc9d69f
JH
188
189Documentation
190--------------
191Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
192
193GIT
194---
a7154e91 195Part of the gitlink:git[7] suite
7fc9d69f 196