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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 checkout -b 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>^, 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. master~3
           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, :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.  :path (with an empty part before the
           colon) is a special case of the syntax described next: content recorded in the index
           at the given path. 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  = 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.

       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