git-rev-parse: Fix --short= option parsing
[git/git.git] / Documentation / git-rev-parse.txt
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1git-rev-parse(1)
2================
3
4NAME
5----
5077fa9c 6git-rev-parse - Pick out and massage parameters.
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7
8
9SYNOPSIS
10--------
11'git-rev-parse' [ --option ] <args>...
12
13DESCRIPTION
14-----------
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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.
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22
23
24OPTIONS
25-------
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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::
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57 When showing object names, prefix them with '{caret}' and
58 strip '{caret}' prefix from the object names that already have
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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
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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::
5f94c730 71 When the command is invoked from a subdirectory, show the
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72 path of the current directory relative to the top-level
73 directory.
7fc9d69f 74
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75--show-cdup::
76 When the command is invoked from a subdirectory, show the
77 path of the top-level directory relative to the current
78 directory (typically a sequence of "../", or an empty string).
79
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80--since=datestring, --after=datestring::
81 Parses the date string, and outputs corresponding
82 --max-age= parameter for git-rev-list command.
83
84--until=datestring, --before=datestring::
85 Parses the date string, and outputs corresponding
86 --min-age= parameter for git-rev-list command.
87
7fc9d69f 88<args>...::
5077fa9c 89 Flags and parameters to be parsed.
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90
91
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92SPECIFYING REVISIONS
93--------------------
94
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95A revision parameter typically, but not necessarily, names a
96commit object. They use what is called an 'extended SHA1'
97syntax.
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98
99* The full SHA1 object name (40-byte hexadecimal string), or
100 a substring of such that is unique within the repository.
101 E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
102 name the same commit object if there are no other object in
103 your repository whose object name starts with dae86e.
104
105* A symbolic ref name. E.g. 'master' typically means the commit
106 object referenced by $GIT_DIR/refs/heads/master. If you
107 happen to have both heads/master and tags/master, you can
72e9340c 108 explicitly say 'heads/master' to tell git which one you mean.
3a45f625 109
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110* A suffix '{caret}' to a revision parameter means the first parent of
111 that commit object. '{caret}<n>' means the <n>th parent (i.e.
112 'rev{caret}'
113 is equivalent to 'rev{caret}1'). As a special rule,
114 'rev{caret}0' means the commit itself and is used when 'rev' is the
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115 object name of a tag object that refers to a commit object.
116
117* A suffix '~<n>' to a revision parameter means the commit
118 object that is the <n>th generation grand-parent of the named
119 commit object, following only the first parent. I.e. rev~3 is
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120 equivalent to rev{caret}{caret}{caret} which is equivalent to\
121 rev{caret}1{caret}1{caret}1.
3a45f625 122
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123* A suffix '{caret}' followed by an object type name enclosed in
124 brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
125 could be a tag, and dereference the tag recursively until an
126 object of that type is found or the object cannot be
127 dereferenced anymore (in which case, barf). `rev{caret}0`
128 introduced earlier is a short-hand for `rev{caret}\{commit\}`.
129
130* A suffix '{caret}' followed by an empty brace pair
131 (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag,
132 and dereference the tag recursively until a non-tag object is
133 found.
134
babfaba2 135'git-rev-parse' also accepts a prefix '{caret}' to revision parameter,
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136which is passed to 'git-rev-list'. Two revision parameters
137concatenated with '..' is a short-hand for writing a range
babfaba2 138between them. I.e. 'r1..r2' is equivalent to saying '{caret}r1 r2'
3a45f625 139
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140Here is an illustration, by Jon Loeliger. Both node B and C are
141a commit parents of commit node A. Parent commits are ordered
142left-to-right.
143
144 G H I J
145 \ / \ /
146 D E F
147 \ | /
148 \ | /
149 \|/
150 B C
151 \ /
152 \ /
153 A
154
155 A = = A^0
156 B = A^ = A^1 = A~1
157 C = A^2 = A^2
158 D = A^^ = A^1^1 = A~2
159 E = B^2 = A^^2
160 F = B^3 = A^^3
161 G = A^^^ = A^1^1^1 = A~3
162 H = D^2 = B^^2 = A^^^2 = A~2^2
163 I = F^ = B^3^ = A^^3^
164 J = F^2 = B^3^2 = A^^3^2
165
3a45f625 166
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167Author
168------
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169Written by Linus Torvalds <torvalds@osdl.org> and
170Junio C Hamano <junkio@cox.net>
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171
172Documentation
173--------------
174Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
175
176GIT
177---
a7154e91 178Part of the gitlink:git[7] suite
7fc9d69f 179