GIT-REV-PARSE(1) Git Manual GIT-REV-PARSE(1)NAMEgit-rev-parse - Pick out and massage parameters
SYNOPSISgit-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 underlying
git-rev-list command they use internally and flags and parameters for
other commands they use as the 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-dash-dash
Only meaningful in --parseopt mode. Tells the option parser to
echo out the first -- met instead of skipping it.
--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.
--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-*).
--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").
--all Show all refs found in $GIT_DIR/refs.
--branches
Show branch refs found in $GIT_DIR/refs/heads.
--tags Show tag refs found in $GIT_DIR/refs/tags.
--remotes
Show tag refs found in $GIT_DIR/refs/remotes.
--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 else show the path to the .git
directory.
--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".
--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
Parses the date string, and outputs corresponding --max-age=
parameter for git-rev-list command.
--until=datestring, --before=datestring
Parses the date string, and outputs corresponding --min-age=
parameter for git-rev-list command.
<args>...
Flags and parameters to be parsed.
SPECIFYING REVISIONS
A revision parameter typically, but not necessarily, names a commit
object. They use what is called an extended SHA1 syntax. Here are
various ways to spell object names. The ones listed near the end of
this list are to name trees and blobs contained in a commit.
· The full SHA1 object name (40-byte hexadecimal string), or a
substring of such that is unique within the repository. E.g.
dae86e1950b1277e545cee180551750029cfe735 and dae86e both name the
same commit object if there are no other object in your repository
whose object name starts with dae86e.
· An output from git-describe; i.e. a closest tag, followed by a dash,
a g, and an abbreviated object name.
· A symbolic ref name. E.g. master typically means the commit object
referenced by $GIT_DIR/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 and MERGE_HEAD);
2. otherwise, $GIT_DIR/refs/<name> if exists;
3. otherwise, $GIT_DIR/refs/tags/<name> if exists;
4. otherwise, $GIT_DIR/refs/heads/<name> if exists;
5. otherwise, $GIT_DIR/refs/remotes/<name> if exists;
6. otherwise, $GIT_DIR/refs/remotes/<name>/HEAD if exists.
· A ref followed by the suffix @ with a date specification enclosed in
a brace pair (e.g. {yesterday}, {1 month 2 weeks 3 days 1 hour 1
second ago} or {1979-02-26 18:30:00}) to specify the value of the
ref at a prior point in time. This suffix may only be used
immediately following a ref name and the ref must have an existing
log ($GIT_DIR/logs/<ref>).
· A ref followed by the suffix @ with an ordinal specification
enclosed in a brace pair (e.g. {1}, {15}) to specify 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/<ref>).
· You can use the @ construct with an empty ref part to get at a
reflog of the current branch. For example, if you are on the branch
blabla, then @{1} means the same as blabla@{1}.
· 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.
· 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 parent. I.e. rev~3 is equivalent to rev^^^
which is equivalent to rev^1^1^1. See below for a illustration of
the usage of this form.
· A suffix ^ followed by an object type name enclosed in brace pair
(e.g. v0.99.8^{commit}) 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 introduced earlier is a short-hand for rev^{commit}.
· A suffix ^ followed by an empty brace pair (e.g. v0.99.8^{}) means
the object could be a tag, and dereference the tag recursively until
a non-tag object is found.
· A colon, followed by a slash, followed by a text: this names a
commit whose commit message starts with the specified text. 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.
· A suffix : followed by a path; this names the blob or tree at the
given path in the tree-ish object named by the part before the
colon.
· A colon, optionally followed by a stage number (0 to 3) and a colon,
followed by a path; this names a blob object in the index at the
given path. 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 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.
"r1..r2" is equivalent to "^r1 r2". It is the difference of two sets
(subtract the set of commits reachable from r1 from the set of commits
reachable from 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 exists. r1^@ notation means all parents of r1. r1^!
includes commit r1 but excludes its all 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 line 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.
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 !.
· Use = if the option takes an argument.
· Use ? to mean that the option is optional (though its use is
discouraged).
· 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(5).
· 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'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 $?`
AUTHOR
Written by Linus Torvalds <torvalds@osdl.org> . Junio C Hamano
<junkio@cox.net> and Pierre Habouzit <madcoder@debian.org>
DOCUMENTATION
Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
GIT
Part of the git(7) suite
Git 1.5.5.2 10/21/2008 GIT-REV-PARSE(1)
