1 SPECIFYING REVISIONS
2 --------------------
4 A revision parameter '<rev>' typically, but not necessarily, names a
5 commit object. It uses what is called an 'extended SHA1'
6 syntax. Here are various ways to spell object names. The
7 ones listed near the end of this list name trees and
8 blobs contained in a commit.
10 '<sha1>', e.g. 'dae86e1950b1277e545cee180551750029cfe735', 'dae86e'::
11 The full SHA1 object name (40-byte hexadecimal string), or
12 a leading substring that is unique within the repository.
13 E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
14 name the same commit object if there is no other object in
15 your repository whose object name starts with dae86e.
17 '<describeOutput>', e.g. 'v1.7.4.2-679-g3bee7fb'::
18 Output from `git describe`; i.e. a closest tag, optionally
19 followed by a dash and a number of commits, followed by a dash, a
20 'g', and an abbreviated object name.
22 '<refname>', e.g. 'master', 'heads/master', 'refs/heads/master'::
23 A symbolic ref name. E.g. 'master' typically means the commit
24 object referenced by 'refs/heads/master'. If you
25 happen to have both 'heads/master' and 'tags/master', you can
26 explicitly say 'heads/master' to tell git which one you mean.
27 When ambiguous, a '<name>' is disambiguated by taking the
28 first match in the following rules:
30 . If '$GIT_DIR/<name>' exists, that is what you mean (this is usually
31 useful only for 'HEAD', 'FETCH_HEAD', 'ORIG_HEAD', 'MERGE_HEAD'
32 and 'CHERRY_PICK_HEAD');
34 . otherwise, 'refs/<name>' if it exists;
36 . otherwise, 'refs/tags/<refname>' if it exists;
38 . otherwise, 'refs/heads/<name>' if it exists;
40 . otherwise, 'refs/remotes/<name>' if it exists;
42 . otherwise, 'refs/remotes/<name>/HEAD' if it exists.
43 +
44 'HEAD' names the commit on which you based the changes in the working tree.
45 'FETCH_HEAD' records the branch which you fetched from a remote repository
46 with your last `git fetch` invocation.
47 'ORIG_HEAD' is created by commands that move your 'HEAD' in a drastic
48 way, to record the position of the 'HEAD' before their operation, so that
49 you can easily change the tip of the branch back to the state before you ran
50 them.
51 'MERGE_HEAD' records the commit(s) which you are merging into your branch
52 when you run `git merge`.
53 'CHERRY_PICK_HEAD' records the commit which you are cherry-picking
54 when you run `git cherry-pick`.
55 +
56 Note that any of the 'refs/*' cases above may come either from
57 the '$GIT_DIR/refs' directory or from the '$GIT_DIR/packed-refs' file.
59 '<refname>@\{<date>\}', e.g. 'master@\{yesterday\}', 'HEAD@\{5 minutes ago\}'::
60 A ref followed by the suffix '@' with a date specification
61 enclosed in a brace
62 pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1
63 second ago\}' or '\{1979-02-26 18:30:00\}') specifies the value
64 of the ref at a prior point in time. This suffix may only be
65 used immediately following a ref name and the ref must have an
66 existing log ('$GIT_DIR/logs/<ref>'). Note that this looks up the state
67 of your *local* ref at a given time; e.g., what was in your local
68 'master' branch last week. If you want to look at commits made during
69 certain times, see '--since' and '--until'.
71 '<refname>@\{<n>\}', e.g. 'master@\{1\}'::
72 A ref followed by the suffix '@' with an ordinal specification
73 enclosed in a brace pair (e.g. '\{1\}', '\{15\}') specifies
74 the n-th prior value of that ref. For example 'master@\{1\}'
75 is the immediate prior value of 'master' while 'master@\{5\}'
76 is the 5th prior value of 'master'. This suffix may only be used
77 immediately following a ref name and the ref must have an existing
78 log ('$GIT_DIR/logs/<refname>').
80 '@\{<n>\}', e.g. '@\{1\}'::
81 You can use the '@' construct with an empty ref part to get at a
82 reflog entry of the current branch. For example, if you are on
83 branch 'blabla' then '@\{1\}' means the same as 'blabla@\{1\}'.
85 '@\{-<n>\}', e.g. '@\{-1\}'::
86 The construct '@\{-<n>\}' means the <n>th branch checked out
87 before the current one.
89 '<refname>@\{upstream\}', e.g. 'master@\{upstream\}', '@\{u\}'::
90 The suffix '@\{upstream\}' to a ref (short form '<refname>@\{u\}') refers to
91 the branch the ref is set to build on top of. A missing ref defaults
92 to the current branch.
94 '<rev>{caret}', e.g. 'HEAD{caret}, v1.5.1{caret}0'::
95 A suffix '{caret}' to a revision parameter means the first parent of
96 that commit object. '{caret}<n>' means the <n>th parent (i.e.
97 '<rev>{caret}'
98 is equivalent to '<rev>{caret}1'). As a special rule,
99 '<rev>{caret}0' means the commit itself and is used when '<rev>' is the
100 object name of a tag object that refers to a commit object.
102 '<rev>{tilde}<n>', e.g. 'master{tilde}3'::
103 A suffix '{tilde}<n>' to a revision parameter means the commit
104 object that is the <n>th generation grand-parent of the named
105 commit object, following only the first parents. I.e. '<rev>{tilde}3' is
106 equivalent to '<rev>{caret}{caret}{caret}' which is equivalent to
107 '<rev>{caret}1{caret}1{caret}1'. See below for an illustration of
108 the usage of this form.
110 '<rev>{caret}\{<type>\}', e.g. 'v0.99.8{caret}\{commit\}'::
111 A suffix '{caret}' followed by an object type name enclosed in
112 brace pair means the object
113 could be a tag, and dereference the tag recursively until an
114 object of that type is found or the object cannot be
115 dereferenced anymore (in which case, barf). '<rev>{caret}0'
116 is a short-hand for '<rev>{caret}\{commit\}'.
118 '<rev>{caret}\{\}', e.g. 'v0.99.8{caret}\{\}'::
119 A suffix '{caret}' followed by an empty brace pair
120 means the object could be a tag,
121 and dereference the tag recursively until a non-tag object is
122 found.
124 '<rev>{caret}\{/<text>\}', e.g. 'HEAD^{/fix nasty bug}'::
125 A suffix '{caret}' to a revision parameter, followed by a brace
126 pair that contains a text led by a slash,
127 is the same as the ':/fix nasty bug' syntax below except that
128 it returns the youngest matching commit which is reachable from
129 the '<rev>' before '{caret}'.
131 ':/<text>', e.g. ':/fix nasty bug'::
132 A colon, followed by a slash, followed by a text, names
133 a commit whose commit message matches the specified regular expression.
134 This name returns the youngest matching commit which is
135 reachable from any ref. If the commit message starts with a
136 '!' you have to repeat that; the special sequence ':/!',
137 followed by something else than '!', is reserved for now.
138 The regular expression can match any part of the commit message. To
139 match messages starting with a string, one can use e.g. ':/^foo'.
141 '<rev>:<path>', e.g. 'HEAD:README', ':README', 'master:./README'::
142 A suffix ':' followed by a path names the blob or tree
143 at the given path in the tree-ish object named by the part
144 before the colon.
145 ':path' (with an empty part before the colon)
146 is a special case of the syntax described next: content
147 recorded in the index at the given path.
148 A path starting with './' or '../' is relative to the current working directory.
149 The given path will be converted to be relative to the working tree's root directory.
150 This is most useful to address a blob or tree from a commit or tree that has
151 the same tree structure as the working tree.
153 ':<n>:<path>', e.g. ':0:README', ':README'::
154 A colon, optionally followed by a stage number (0 to 3) and a
155 colon, followed by a path, names a blob object in the
156 index at the given path. A missing stage number (and the colon
157 that follows it) names a stage 0 entry. During a merge, stage
158 1 is the common ancestor, stage 2 is the target branch's version
159 (typically the current branch), and stage 3 is the version from
160 the branch which is being merged.
162 Here is an illustration, by Jon Loeliger. Both commit nodes B
163 and C are parents of commit node A. Parent commits are ordered
164 left-to-right.
166 ........................................
167 G H I J
168 \ / \ /
169 D E F
170 \ | / \
171 \ | / |
172 \|/ |
173 B C
174 \ /
175 \ /
176 A
177 ........................................
179 A = = A^0
180 B = A^ = A^1 = A~1
181 C = A^2 = A^2
182 D = A^^ = A^1^1 = A~2
183 E = B^2 = A^^2
184 F = B^3 = A^^3
185 G = A^^^ = A^1^1^1 = A~3
186 H = D^2 = B^^2 = A^^^2 = A~2^2
187 I = F^ = B^3^ = A^^3^
188 J = F^2 = B^3^2 = A^^3^2
191 SPECIFYING RANGES
192 -----------------
194 History traversing commands such as `git log` operate on a set
195 of commits, not just a single commit. To these commands,
196 specifying a single revision with the notation described in the
197 previous section means the set of commits reachable from that
198 commit, following the commit ancestry chain.
200 To exclude commits reachable from a commit, a prefix '{caret}'
201 notation is used. E.g. '{caret}r1 r2' means commits reachable
202 from 'r2' but exclude the ones reachable from 'r1'.
204 This set operation appears so often that there is a shorthand
205 for it. When you have two commits 'r1' and 'r2' (named according
206 to the syntax explained in SPECIFYING REVISIONS above), you can ask
207 for commits that are reachable from r2 excluding those that are reachable
208 from r1 by '{caret}r1 r2' and it can be written as 'r1..r2'.
210 A similar notation 'r1\...r2' is called symmetric difference
211 of 'r1' and 'r2' and is defined as
212 'r1 r2 --not $(git merge-base --all r1 r2)'.
213 It is the set of commits that are reachable from either one of
214 'r1' or 'r2' but not from both.
216 Two other shorthands for naming a set that is formed by a commit
217 and its parent commits exist. The 'r1{caret}@' notation means all
218 parents of 'r1'. 'r1{caret}!' includes commit 'r1' but excludes
219 all of its parents.
221 Here are a handful of examples:
223 D G H D
224 D F G H I J D F
225 ^G D H D
226 ^D B E I J F B
227 B...C G H D E B C
228 ^D B C E I J F B C
229 C^@ I J F
230 F^! D G H D F