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
Operation Modes
Each of these options must appear first on the command line.
--parseopt
Use git rev-parse in option parsing mode (see PARSEOPT section
below).
--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.
Options for --parseopt
--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.
--stuck-long
Only meaningful in --parseopt mode. Output the options in their
long form if available, and with their arguments stuck.
Options for Filtering
--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.
Options for Output
--default <arg>
If there is no parameter given by the user, use <arg> instead.
--prefix <arg>
Behave as if git rev-parse was invoked from the <arg> subdirectory
of the working tree. Any relative filenames are resolved as if they
are prefixed by <arg> and will be printed in that form.
This can be used to convert arguments to a command run in a
subdirectory so that they can still be used after moving to the
top-level of the repository. For example:
prefix=$(git rev-parse --show-prefix)
cd "$(git rev-parse --show-toplevel)"
eval "set -- $(git rev-parse --sq --prefix "$prefix" "$@")"
--verify
Verify that exactly one parameter is provided, and that it can be
turned into a raw 20-byte SHA-1 that can be used to access the
object database. If so, emit it to the standard output; otherwise,
error out.
If you want to make sure that the output actually names an object
in your object database and/or can be used as a specific type of
object you require, you can add the ^{type} peeling operator to the
parameter. For example, git rev-parse "$VAR^{commit}" will make
sure $VAR names an existing object that is a commit-ish (i.e. a
commit, or an annotated tag that points at a commit). To make sure
that $VAR names an existing object of any type, git rev-parse
"$VAR^{object}" can be used.
-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. SHA-1s for valid object names are printed
to stdout on success.
--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.
--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.
--short, --short=number
Instead of outputting the full SHA-1 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.
--symbolic
Usually the object names are output in SHA-1 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").
Options for Objects
--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 /*.
--exclude=<glob-pattern>
Do not include refs matching <glob-pattern> that the next --all,
--branches, --tags, --remotes, or --glob would otherwise consider.
Repetitions of this option accumulate exclusion patterns up to the
next --all, --branches, --tags, --remotes, or --glob option (other
options or arguments do not clear accumulated patterns).
The patterns given should not begin with refs/heads, refs/tags, or
refs/remotes when applied to --branches, --tags, or --remotes,
respectively, and they must begin with refs/ when applied to --glob
or --all. If a trailing /* is intended, it must be given
explicitly.
--disambiguate=<prefix>
Show every object whose name begins with the given prefix. The
<prefix> must be at least 4 hexadecimal digits long to avoid
listing each and every object in the repository by mistake.
Options for Files
--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.
--git-dir
Show $GIT_DIR if defined. Otherwise show the path to the .git
directory. The path shown, when relative, is relative to the
current working 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.
--git-common-dir
Show $GIT_COMMON_DIR if defined, else $GIT_DIR.
--is-inside-git-dir
When the current working directory is below the repository
directory print "true", otherwise "false".
--is-inside-work-tree
When the current working directory is inside the work tree of the
repository print "true", otherwise "false".
--is-bare-repository
When the repository is bare print "true", otherwise "false".
--resolve-git-dir <path>
Check if <path> is a valid repository or a gitfile that points at a
valid repository, and print the location of the repository. If
<path> is a gitfile then the resolved path to the real repository
is printed.
--git-path <path>
Resolve "$GIT_DIR/<path>" and takes other path relocation variables
such as $GIT_OBJECT_DIRECTORY, $GIT_INDEX_FILE... into account. For
example, if $GIT_OBJECT_DIRECTORY is set to /foo/bar then "git
rev-parse --git-path objects/abc" returns /foo/bar/abc.
--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).
--show-prefix
When the command is invoked from a subdirectory, show the path of
the current directory relative to the top-level directory.
--show-toplevel
Show the absolute path of the top-level directory.
--shared-index-path
Show the path to the shared index file in split index mode, or
empty if not in split-index mode.
Other Options
--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 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.
<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.
<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.
<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. 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.
<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
Two 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.
While <rev>^<n> was about specifying a single commit parent, these two
notations consider all 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).
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
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
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 one or more) are used for the usage. The lines after the separator describe the options. Each line of options has this format: <opt-spec><flags>*<arg-hint>? 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. May not contain any of the <flags> characters. h,help, dry-run and f are examples of correct <opt-spec>. <flags> <flags> are of *, =, ? or !. * Use = if the option takes an argument. * Use ? to mean that the option takes an optional argument. You probably want to use the --stuck-long mode to be able to unambiguously parse the optional argument. * Use * to mean that this option should not be listed in the usage generated for the -h argument. It's shown for --help-all as documented in gitcli(7). * Use ! to not make the corresponding negated long option available. <arg-hint> <arg-hint>, if specified, is used as a name of the argument in the help output, for options that take arguments. <arg-hint> is terminated by the first whitespace. It is customary to use a dash to separate words in a multi-word argument hint. 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'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 baz=arg another cool option --baz with a named argument qux?path qux may take a path argument but has meaning by itself An option group Header C? option C with an optional argument" eval "$(echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?)" Usage text When "$@" is -h or --help in the above example, the following usage text would be shown: usage: 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 --baz <arg> another cool option --baz with a named argument --qux[=<path>] qux may take a path argument but has meaning by itself An option group Header -C[...] option C with an optional argument
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
* Print the object name of the current commit:
$ git rev-parse --verify HEAD
* Print the commit object name from the revision in the $REV shell
variable:
$ git rev-parse --verify $REV^{commit}
This will error out if $REV is empty or not a valid revision.
* Similar to 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
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