GIT-REV-PARSE(1)                                              GIT-REV-PARSE(1)



NAME
       git-rev-parse - Pick out and massage parameters

SYNOPSIS
       git rev-parse [ --option ] <args>...


DESCRIPTION
       Many git porcelainish commands take mixture of flags (i.e. parameters
       that begin with a dash -) and parameters meant for the underlying git
       rev-list command they use internally and flags and parameters for the
       other commands they use downstream of git rev-list. This command is
       used to distinguish between them.


OPTIONS
       --parseopt
              Use git rev-parse in option parsing mode (see PARSEOPT section
              below).


       --keep-dashdash
              Only meaningful in --parseopt mode. Tells the option parser to
              echo out the first -- met instead of skipping it.


       --stop-at-non-option
              Only meaningful in --parseopt mode. Lets the option parser stop
              at the first non-option argument. This can be used to parse
              sub-commands that take options themselves.


       --sq-quote
              Use git rev-parse in shell quoting mode (see SQ-QUOTE section
              below). In contrast to the --sq option below, this mode does
              only quoting. Nothing else is done to command input.


       --revs-only
              Do not output flags and parameters not meant for git rev-list
              command.


       --no-revs
              Do not output flags and parameters meant for git rev-list
              command.


       --flags
              Do not output non-flag parameters.


       --no-flags
              Do not output flag parameters.


       --default <arg>
              If there is no parameter given by the user, use <arg> instead.


       --verify
              The parameter given must be usable as a single, valid object
              name. Otherwise barf and abort.


       -q, --quiet
              Only meaningful in --verify mode. Do not output an error message
              if the first argument is not a valid object name; instead exit
              with non-zero status silently.


       --sq   Usually the output is made one line per flag and parameter. This
              option makes output a single line, properly quoted for
              consumption by shell. Useful when you expect your parameter to
              contain whitespaces and newlines (e.g. when using pickaxe -S
              with git diff-*). In contrast to the --sq-quote option, the
              command input is still interpreted as usual.


       --not  When showing object names, prefix them with ^ and strip ^ prefix
              from the object names that already have one.


       --symbolic
              Usually the object names are output in SHA1 form (with possible
              ^ prefix); this option makes them output in a form as close to
              the original input as possible.


       --symbolic-full-name
              This is similar to --symbolic, but it omits input that are not
              refs (i.e. branch or tag names; or more explicitly
              disambiguating "heads/master" form, when you want to name the
              "master" branch when there is an unfortunately named tag
              "master"), and show them as full refnames (e.g.
              "refs/heads/master").


       --abbrev-ref[=(strict|loose)]
              A non-ambiguous short name of the objects name. The option
              core.warnAmbiguousRefs is used to select the strict abbreviation
              mode.


       --all  Show all refs found in refs/.


       --branches[=pattern], --tags[=pattern], --remotes[=pattern]
              Show all branches, tags, or remote-tracking branches,
              respectively (i.e., refs found in refs/heads, refs/tags, or
              refs/remotes, respectively).

              If a pattern is given, only refs matching the given shell glob
              are shown. If the pattern does not contain a globbing character
              (?, *, or [), it is turned into a prefix match by appending /*.


       --glob=pattern
              Show all refs matching the shell glob pattern pattern. If the
              pattern does not start with refs/, this is automatically
              prepended. If the pattern does not contain a globbing character
              (?, *, or [), it is turned into a prefix match by appending /*.


       --show-toplevel
              Show the absolute path of the top-level directory.


       --show-prefix
              When the command is invoked from a subdirectory, show the path
              of the current directory relative to the top-level directory.


       --show-cdup
              When the command is invoked from a subdirectory, show the path
              of the top-level directory relative to the current directory
              (typically a sequence of "../", or an empty string).


       --git-dir
              Show $GIT_DIR if defined. Otherwise show the path to the .git
              directory, relative to the current directory.

              If $GIT_DIR is not defined and the current directory is not
              detected to lie in a git repository or work tree print a message
              to stderr and exit with nonzero status.


       --is-inside-git-dir
              When the current working directory is below the repository
              directory print "true", otherwise "false".


       --is-inside-work-tree
              When the current working directory is inside the work tree of
              the repository print "true", otherwise "false".


       --is-bare-repository
              When the repository is bare print "true", otherwise "false".


       --local-env-vars
              List the GIT_* environment variables that are local to the
              repository (e.g. GIT_DIR or GIT_WORK_TREE, but not GIT_EDITOR).
              Only the names of the variables are listed, not their value,
              even if they are set.


       --short, --short=number
              Instead of outputting the full SHA1 values of object names try
              to abbreviate them to a shorter unique name. When no length is
              specified 7 is used. The minimum length is 4.


       --since=datestring, --after=datestring
              Parse the date string, and output the corresponding --max-age=
              parameter for git rev-list.


       --until=datestring, --before=datestring
              Parse the date string, and output the corresponding --min-age=
              parameter for git rev-list.


       <args>...
              Flags and parameters to be parsed.


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


PARSEOPT
       In --parseopt mode, git rev-parse helps massaging options to bring to
       shell scripts the same facilities C builtins have. It works as an
       option normalizer (e.g. splits single switches aggregate values), a bit
       like getopt(1) does.


       It takes on the standard input the specification of the options to
       parse and understand, and echoes on the standard output a string
       suitable for sh(1) eval to replace the arguments with normalized ones.
       In case of error, it outputs usage on the standard error stream, and
       exits with code 129.


       Note: Make sure you quote the result when passing it to eval. See below
       for an example.


   Input Format
       git rev-parse --parseopt input format is fully text based. It has two
       parts, separated by a line that contains only --. The lines before the
       separator (should be more than one) are used for the usage. The lines
       after the separator describe the options.


       Each line of options has this format:

       <opt_spec><flags>* SP+ help LF





       <opt_spec>
              its format is the short option character, then the long option
              name separated by a comma. Both parts are not required, though
              at least one is necessary. h,help, dry-run and f are all three
              correct <opt_spec>.


       <flags>
               <flags> are of *, =, ? or !.


              o  Use = if the option takes an argument.

              o  Use ? to mean that the option is optional (though its use is
                 discouraged).

              o  Use * to mean that this option should not be listed in the
                 usage generated for the -h argument. It&#8217;s shown for
                 --help-all as documented in gitcli(7).

              o  Use ! to not make the corresponding negated long option
                 available.

              The remainder of the line, after stripping the spaces, is used
              as the help associated to the option.


              Blank lines are ignored, and lines that don&#8217;t match this
              specification are used as option group headers (start the line
              with a space to create such lines on purpose).


   Example
       OPTS_SPEC="\
       some-command [options] <args>...

       some-command does foo and bar!
       --
       h,help    show the help

       foo       some nifty option --foo
       bar=      some cool option --bar with an argument

         An option group Header
       C?        option C with an optional argument"

       eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)"





SQ-QUOTE
       In --sq-quote mode, git rev-parse echoes on the standard output a
       single line suitable for sh(1) eval. This line is made by normalizing
       the arguments following --sq-quote. Nothing other than quoting the
       arguments is done.


       If you want command input to still be interpreted as usual by git
       rev-parse before the output is shell quoted, see the --sq option.


   Example
       $ cat >your-git-script.sh <<\EOF
       #!/bin/sh
       args=$(git rev-parse --sq-quote "$@")   # quote user-supplied arguments
       command="git frotz -n24 $args"          # and use it inside a handcrafted
                                               # command line
       eval "$command"
       EOF

       $ sh your-git-script.sh "a b'c"





EXAMPLES
       o  Print the object name of the current commit:


          $ git rev-parse --verify HEAD


       o  Print the commit object name from the revision in the $REV shell
          variable:


          $ git rev-parse --verify $REV


          This will error out if $REV is empty or not a valid revision.

       o  Same as above:


          $ git rev-parse --default master --verify $REV


          but if $REV is empty, the commit object name from master will be
          printed.

GIT
       Part of the git(1) suite




                                                              GIT-REV-PARSE(1)
