gitrevisions

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, 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}
           The suffix @{upstream} to a branchname (short form <branchname>@{u})
           refers to the branch that the branch specified by branchname is set
           to build on top of (configured with branch.<name>.remote and
           branch.<name>.merge). A missing branchname defaults to the current
           one. These suffixes are also accepted when spelled in uppercase, and
           they mean the same thing no matter the case.

       [<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). Since our push destination is in a
           remote repository, of course, we report the local tracking branch
           that corresponds to that branch (i.e., something in refs/remotes/).

           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.

   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.

   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 then 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 2.29.2                         10/30/2020                    GITREVISIONS(7)