GITREVISIONS(7)                                                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 can be
       reached from that commit. In the latter case one can also specify a
       range of revisions explicitly.


       In addition, some Git commands (such as git-show(1)) 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 SHA1 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.


       <sha1>, e.g. dae86e1950b1277e545cee180551750029cfe735, dae86e
              The full SHA1 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
              <name> is disambiguated by taking the first match in the
              following rules:


              1. If $GIT_DIR/<name> 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/<name> if it exists;

              3. otherwise, refs/tags/<refname> if it exists;

              4. otherwise, refs/heads/<name> if it exists;

              5. otherwise, refs/remotes/<name> if it exists;

              6. otherwise, refs/remotes/<name>/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.

       <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 checked out before
              the current one.


       <refname>@{upstream}, e.g. master@{upstream}, @{u}
              The suffix @{upstream} to a ref (short form <refname>@{u})
              refers to the branch the ref is set to build on top of. A
              missing ref defaults to the current branch.


       <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 grand-parent 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 the object could be a tag, and dereference the tag
              recursively until an object of that type is found or the object
              cannot be dereferenced anymore (in which case, barf). <rev>^0 is
              a short-hand for <rev>^{commit}.


       <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. If the commit message starts with a !
              you have to repeat that; the special sequence :/!, followed by
              something else than !, is reserved for now. The regular
              expression can match any part of the commit message. To match
              messages starting with a string, one can use e.g. :/^foo.


       <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&#8217;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&#8217;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. To these commands, specifying a
       single revision with the notation described in the previous section
       means the set of commits reachable from that commit, following the
       commit ancestry chain.


       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.


       This 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.


       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 or r2 but not
       from both.


       Two other shorthands for naming a set that is formed by a commit and
       its parent commits exist. The r1^@ notation means all parents of r1.
       r1^! includes commit r1 but excludes all of its parents.


       Here are a handful of examples:

       D                G H D
       D F              G H I J D F
       ^G D             H D
       ^D B             E I J F B
       B...C            G H D E B C
       ^D B C           E I J F B C
       C^@              I J F
       F^! D            G H D F


SEE ALSO
       git-rev-parse(1)


GIT
       Part of the git(1) suite




                                                               GITREVISIONS(7)
