Merge http://www.kernel.org/pub/scm/gitk/gitk
[git/git.git] / Documentation / git-rev-parse.txt
1 git-rev-parse(1)
2 ================
3
4 NAME
5 ----
6 git-rev-parse - Pick out and massage parameters.
7
8
9 SYNOPSIS
10 --------
11 'git-rev-parse' [ --option ] <args>...
12
13 DESCRIPTION
14 -----------
15
16 Many git Porcelainish commands take mixture of flags
17 (i.e. parameters that begin with a dash '-') and parameters
18 meant for underlying `git-rev-list` command they use internally
19 and flags and parameters for other commands they use as the
20 downstream of `git-rev-list`. This command is used to
21 distinguish between them.
22
23
24 OPTIONS
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 --show-prefix::
71 When the command is invoked from a directory show the
72 path of the current directory relative to the top-level
73 directory.
74
75 <args>...::
76 Flags and parameters to be parsed.
77
78
79 SPECIFYING REVISIONS
80 --------------------
81
82 A revision parameter typically, but not necessarily, names a
83 commit object. They use what is called an 'extended SHA1'
84 syntax.
85
86 * The full SHA1 object name (40-byte hexadecimal string), or
87 a substring of such that is unique within the repository.
88 E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
89 name the same commit object if there are no other object in
90 your repository whose object name starts with dae86e.
91
92 * A symbolic ref name. E.g. 'master' typically means the commit
93 object referenced by $GIT_DIR/refs/heads/master. If you
94 happen to have both heads/master and tags/master, you can
95 explicitly say 'heads/master' to tell git which one you mean.
96
97 * A suffix '{caret}' to a revision parameter means the first parent of
98 that commit object. '{caret}<n>' means the <n>th parent (i.e.
99 'rev{caret}'
100 is equivalent to 'rev{caret}1'). As a special rule,
101 'rev{caret}0' means the commit itself and is used when 'rev' is the
102 object name of a tag object that refers to a commit object.
103
104 * A suffix '~<n>' to a revision parameter means the commit
105 object that is the <n>th generation grand-parent of the named
106 commit object, following only the first parent. I.e. rev~3 is
107 equivalent to rev{caret}{caret}{caret} which is equivalent to\
108 rev{caret}1{caret}1{caret}1.
109
110 * A suffix '{caret}' followed by an object type name enclosed in
111 brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
112 could be a tag, and dereference the tag recursively until an
113 object of that type is found or the object cannot be
114 dereferenced anymore (in which case, barf). `rev{caret}0`
115 introduced earlier is a short-hand for `rev{caret}\{commit\}`.
116
117 * A suffix '{caret}' followed by an empty brace pair
118 (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag,
119 and dereference the tag recursively until a non-tag object is
120 found.
121
122 'git-rev-parse' also accepts a prefix '{caret}' to revision parameter,
123 which is passed to 'git-rev-list'. Two revision parameters
124 concatenated with '..' is a short-hand for writing a range
125 between them. I.e. 'r1..r2' is equivalent to saying '{caret}r1 r2'
126
127
128 Author
129 ------
130 Written by Linus Torvalds <torvalds@osdl.org> and
131 Junio C Hamano <junkio@cox.net>
132
133 Documentation
134 --------------
135 Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
136
137 GIT
138 ---
139 Part of the gitlink:git[7] suite
140