gitrevisions(7) Git Manual gitrevisions(7)
NAME
gitrevisions - Specifying revisions and ranges for Git
SYNOPSIS
gitrevisions
DESCRIPTION
Many Git commands take revision parameters as arguments. Depending on the
command, they denote a specific commit or, for commands which walk the
revision graph (such as git-log(1)), all commits which are reachable from
that commit. For commands that walk the revision graph one can also
specify a range of revisions explicitly.
In addition, some Git commands (such as git-show(1) and git-push(1)) can
also take revision parameters which denote other objects than commits,
e.g. blobs ("files") or trees ("directories of files").
SPECIFYING REVISIONS
A revision parameter <rev> typically, but not necessarily, names a commit
object. It uses what is called an extended SHA-1 syntax. Here are various
ways to spell object names. The ones listed near the end of this list
name trees and blobs contained in a commit.
Note
This document shows the "raw" syntax as seen by git. The shell and
other UIs might require additional quoting to protect special
characters and to avoid word splitting.
<sha1>, e.g. dae86e1950b1277e545cee180551750029cfe735, dae86e
The full SHA-1 object name (40-byte hexadecimal string), or a leading
substring that is unique within the repository. E.g.
dae86e1950b1277e545cee180551750029cfe735 and dae86e both name the
same commit object if there is no other object in your repository
whose object name starts with dae86e.
<describeOutput>, e.g. v1.7.4.2-679-g3bee7fb
Output from git describe; i.e. a closest tag, optionally followed by
a dash and a number of commits, followed by a dash, a g, and an
abbreviated object name.
<refname>, e.g. master, heads/master, refs/heads/master
A symbolic ref name. E.g. master typically means the commit object
referenced by refs/heads/master. If you happen to have both
heads/master and tags/master, you can explicitly say heads/master to
tell Git which one you mean. When ambiguous, a <refname> is
disambiguated by taking the first match in the following rules:
1. If $GIT_DIR/<refname> exists, that is what you mean (this is
usually useful only for HEAD, FETCH_HEAD, ORIG_HEAD, MERGE_HEAD
and CHERRY_PICK_HEAD);
2. otherwise, refs/<refname> if it exists;
3. otherwise, refs/tags/<refname> if it exists;
4. otherwise, refs/heads/<refname> if it exists;
5. otherwise, refs/remotes/<refname> if it exists;
6. otherwise, refs/remotes/<refname>/HEAD if it exists.
HEAD names the commit on which you based the changes in the
working tree. FETCH_HEAD records the branch which you fetched
from a remote repository with your last git fetch invocation.
ORIG_HEAD is created by commands that move your HEAD in a drastic
way (git am, git merge, git rebase, git reset), to record the
position of the HEAD before their operation, so that you can
easily change the tip of the branch back to the state before you
ran them. MERGE_HEAD records the commit(s) which you are merging
into your branch when you run git merge. CHERRY_PICK_HEAD
records the commit which you are cherry-picking when you run git
cherry-pick.
Note that any of the refs/* cases above may come either from the
$GIT_DIR/refs directory or from the $GIT_DIR/packed-refs file.
While the ref name encoding is unspecified, UTF-8 is preferred as
some output processing may assume ref names in UTF-8.
@
@ alone is a shortcut for HEAD.
[<refname>]@{<date>}, e.g. master@{yesterday}, HEAD@{5 minutes ago}
A ref followed by the suffix @ with a date specification enclosed in
a brace pair (e.g. {yesterday}, {1 month 2 weeks 3 days 1 hour 1
second ago} or {1979-02-26 18:30:00}) specifies the value of the ref
at a prior point in time. This suffix may only be used immediately
following a ref name and the ref must have an existing log
($GIT_DIR/logs/<ref>). Note that this looks up the state of your
local ref at a given time; e.g., what was in your local master branch
last week. If you want to look at commits made during certain times,
see --since and --until.
<refname>@{<n>}, e.g. master@{1}
A ref followed by the suffix @ with an ordinal specification enclosed
in a brace pair (e.g. {1}, {15}) specifies the n-th prior value of
that ref. For example master@{1} is the immediate prior value of
master while master@{5} is the 5th prior value of master. This suffix
may only be used immediately following a ref name and the ref must
have an existing log ($GIT_DIR/logs/<refname>).
@{<n>}, e.g. @{1}
You can use the @ construct with an empty ref part to get at a reflog
entry of the current branch. For example, if you are on branch blabla
then @{1} means the same as blabla@{1}.
@{-<n>}, e.g. @{-1}
The construct @{-<n>} means the <n>th branch/commit checked out
before the current one.
[<branchname>]@{upstream}, e.g. master@{upstream}, @{u}
A branch B may be set up to build on top of a branch X (configured
with branch.<name>.merge) at a remote R (configured with the branch X
taken from remote R, typically found at refs/remotes/R/X.
[<branchname>]@{push}, e.g. master@{push}, @{push}
The suffix @{push} reports the branch "where we would push to" if git
push were run while branchname was checked out (or the current HEAD
if no branchname is specified). Like for @{upstream}, we report the
remote-tracking branch that corresponds to that branch at the remote.
Here's an example to make it more clear:
$ git config push.default current
$ git config remote.pushdefault myfork
$ git switch -c mybranch origin/master
$ git rev-parse --symbolic-full-name @{upstream}
refs/remotes/origin/master
$ git rev-parse --symbolic-full-name @{push}
refs/remotes/myfork/mybranch
Note in the example that we set up a triangular workflow, where we
pull from one location and push to another. In a non-triangular
workflow, @{push} is the same as @{upstream}, and there is no need
for it.
This suffix is also accepted when spelled in uppercase, and means the
same thing no matter the case.
<rev>^[<n>], e.g. HEAD^, v1.5.1^0
A suffix ^ to a revision parameter means the first parent of that
commit object. ^<n> means the <n>th parent (i.e. <rev>^ is
equivalent to <rev>^1). As a special rule, <rev>^0 means the commit
itself and is used when <rev> is the object name of a tag object that
refers to a commit object.
<rev>~[<n>], e.g. HEAD~, master~3
A suffix ~ to a revision parameter means the first parent of that
commit object. A suffix ~<n> to a revision parameter means the commit
object that is the <n>th generation ancestor of the named commit
object, following only the first parents. I.e. <rev>~3 is equivalent
to <rev>^^^ which is equivalent to <rev>^1^1^1. See below for an
illustration of the usage of this form.
<rev>^{<type>}, e.g. v0.99.8^{commit}
A suffix ^ followed by an object type name enclosed in brace pair
means dereference the object at <rev> recursively until an object of
type <type> is found or the object cannot be dereferenced anymore (in
which case, barf). For example, if <rev> is a commit-ish,
<rev>^{commit} describes the corresponding commit object. Similarly,
if <rev> is a tree-ish, <rev>^{tree} describes the corresponding tree
object. <rev>^0 is a short-hand for <rev>^{commit}.
<rev>^{object} can be used to make sure <rev> names an object that
exists, without requiring <rev> to be a tag, and without
dereferencing <rev>; because a tag is already an object, it does not
have to be dereferenced even once to get to an object.
<rev>^{tag} can be used to ensure that <rev> identifies an existing
tag object.
<rev>^{}, e.g. v0.99.8^{}
A suffix ^ followed by an empty brace pair means the object could be
a tag, and dereference the tag recursively until a non-tag object is
found.
<rev>^{/<text>}, e.g. HEAD^{/fix nasty bug}
A suffix ^ to a revision parameter, followed by a brace pair that
contains a text led by a slash, is the same as the :/fix nasty bug
syntax below except that it returns the youngest matching commit
which is reachable from the <rev> before ^.
:/<text>, e.g. :/fix nasty bug
A colon, followed by a slash, followed by a text, names a commit
whose commit message matches the specified regular expression. This
name returns the youngest matching commit which is reachable from any
ref, including HEAD. The regular expression can match any part of the
commit message. To match messages starting with a string, one can use
e.g. :/^foo. The special sequence :/! is reserved for modifiers to
what is matched. :/!-foo performs a negative match, while :/!!foo
matches a literal ! character, followed by foo. Any other sequence
beginning with :/! is reserved for now. Depending on the given text,
the shell's word splitting rules might require additional quoting.
<rev>:<path>, e.g. HEAD:README, master:./README
A suffix : followed by a path names the blob or tree at the given
path in the tree-ish object named by the part before the colon. A
path starting with ./ or ../ is relative to the current working
directory. The given path will be converted to be relative to the
working tree's root directory. This is most useful to address a blob
or tree from a commit or tree that has the same tree structure as the
working tree.
:[<n>:]<path>, e.g. :0:README, :README
A colon, optionally followed by a stage number (0 to 3) and a colon,
followed by a path, names a blob object in the index at the given
path. A missing stage number (and the colon that follows it) names a
stage 0 entry. During a merge, stage 1 is the common ancestor, stage
2 is the target branch's version (typically the current branch), and
stage 3 is the version from the branch which is being merged.
Here is an illustration, by Jon Loeliger. Both commit nodes B and C are
parents of commit node A. Parent commits are ordered left-to-right.
G H I J
\ / \ /
D E F
\ | / \
\ | / |
\|/ |
B C
\ /
\ /
A
A = = A^0
B = A^ = A^1 = A~1
C = = A^2
D = A^^ = A^1^1 = A~2
E = B^2 = A^^2
F = B^3 = A^^3
G = A^^^ = A^1^1^1 = A~3
H = D^2 = B^^2 = A^^^2 = A~2^2
I = F^ = B^3^ = A^^3^
J = F^2 = B^3^2 = A^^3^2
SPECIFYING RANGES
History traversing commands such as git log operate on a set of commits,
not just a single commit.
For these commands, specifying a single revision, using the notation
described in the previous section, means the set of commits reachable
from the given commit.
Specifying several revisions means the set of commits reachable from any
of the given commits.
A commit's reachable set is the commit itself and the commits in its
ancestry chain.
There are several notations to specify a set of connected commits (called
a "revision range"), illustrated below.
Commit Exclusions
^<rev> (caret) Notation
To exclude commits reachable from a commit, a prefix ^ notation is
used. E.g. ^r1 r2 means commits reachable from r2 but exclude the
ones reachable from r1 (i.e. r1 and its ancestors).
Dotted Range Notations
The .. (two-dot) Range Notation
The ^r1 r2 set operation appears so often that there is a shorthand
for it. When you have two commits r1 and r2 (named according to the
syntax explained in SPECIFYING REVISIONS above), you can ask for
commits that are reachable from r2 excluding those that are reachable
from r1 by ^r1 r2 and it can be written as r1..r2.
The ... (three-dot) Symmetric Difference Notation
A similar notation r1...r2 is called symmetric difference of r1 and
r2 and is defined as r1 r2 --not $(git merge-base --all r1 r2). It is
the set of commits that are reachable from either one of r1 (left
side) or r2 (right side) but not from both.
In these two shorthand notations, you can omit one end and let it default
to HEAD. For example, origin.. is a shorthand for origin..HEAD and asks
"What did I do since I forked from the origin branch?" Similarly,
..origin is a shorthand for HEAD..origin and asks "What did the origin do
since I forked from them?" Note that .. would mean HEAD..HEAD which is an
empty range that is both reachable and unreachable from HEAD.
Commands that are specifically designed to take two distinct ranges (e.g.
"git range-diff R1 R2" to compare two ranges) do exist, but they are
exceptions. Unless otherwise noted, all "git" commands that operate on a
set of commits work on a single revision range. In other words, writing
two "two-dot range notation" next to each other, e.g.
$ git log A..B C..D
does not specify two revision ranges for most commands. Instead it will
name a single connected set of commits, i.e. those that are reachable
from either B or D but are reachable from neither A or C. In a linear
history like this:
---A---B---o---o---C---D
because A and B are reachable from C, the revision range specified by
these two dotted ranges is a single commit D.
Other <rev>^ Parent Shorthand Notations
Three other shorthands exist, particularly useful for merge commits, for
naming a set that is formed by a commit and its parent commits.
The r1^@ notation means all parents of r1.
The r1^! notation includes commit r1 but excludes all of its parents. By
itself, this notation denotes the single commit r1.
The <rev>^-[<n>] notation includes <rev> but excludes the <n>th parent
(i.e. a shorthand for <rev>^<n>..<rev>), with <n> = 1 if not given. This
is typically useful for merge commits where you can just pass <commit>^-
to get all the commits in the branch that was merged in merge commit
<commit> (including <commit> itself).
While <rev>^<n> was about specifying a single commit parent, these three
notations also consider its parents. For example you can say HEAD^2^@,
however you cannot say HEAD^@^2.
REVISION RANGE SUMMARY
<rev>
Include commits that are reachable from <rev> (i.e. <rev> and its
ancestors).
^<rev>
Exclude commits that are reachable from <rev> (i.e. <rev> and its
ancestors).
<rev1>..<rev2>
Include commits that are reachable from <rev2> but exclude those that
are reachable from <rev1>. When either <rev1> or <rev2> is omitted,
it defaults to HEAD.
<rev1>...<rev2>
Include commits that are reachable from either <rev1> or <rev2> but
exclude those that are reachable from both. When either <rev1> or
<rev2> is omitted, it defaults to HEAD.
<rev>^@, e.g. HEAD^@
A suffix ^ followed by an at sign is the same as listing all parents
of <rev> (meaning, include anything reachable from its parents, but
not the commit itself).
<rev>^!, e.g. HEAD^!
A suffix ^ followed by an exclamation mark is the same as giving
commit <rev> and all its parents prefixed with ^ to exclude them (and
their ancestors).
<rev>^-<n>, e.g. HEAD^-, HEAD^-2
Equivalent to <rev>^<n>..<rev>, with <n> = 1 if not given.
Here are a handful of examples using the Loeliger illustration above,
with each step in the notation's expansion and selection carefully spelt
out:
Args Expanded arguments Selected commits
D G H D
D F G H I J D F
^G D H D
^D B E I J F B
^D B C E I J F B C
C I J F C
B..C = ^B C C
B...C = B ^F C G H D E B C
B^- = B^..B
= ^B^1 B E I J F B
C^@ = C^1
= F I J F
B^@ = B^1 B^2 B^3
= D E F D G H E F I J
C^! = C ^C^@
= C ^C^1
= C ^F C
B^! = B ^B^@
= B ^B^1 ^B^2 ^B^3
= B ^D ^E ^F B
F^! D = F ^I ^J D G H D F
SEE ALSO
git-rev-parse(1)
GIT
Part of the git(1) suite
Git 2.40.0 03/13/2023 gitrevisions(7)
git 2.40.0 - Generated Tue Mar 14 07:58:57 CDT 2023