SYNOPSIS
--------
[verse]
-'git check-ref-format' <refname>
-'git check-ref-format' [--branch] <branchname-shorthand>
+'git check-ref-format' [--normalize]
+ [--[no-]allow-onelevel] [--refspec-pattern]
+ <refname>
+'git check-ref-format' --branch <branchname-shorthand>
DESCRIPTION
-----------
status if it is not.
A reference is used in git to specify branches and tags. A
-branch head is stored under the `$GIT_DIR/refs/heads` directory, and
-a tag is stored under the `$GIT_DIR/refs/tags` directory. git
-imposes the following rules on how references are named:
+branch head is stored in the `refs/heads` hierarchy, while
+a tag is stored in the `refs/tags` hierarchy of the ref namespace
+(typically in `$GIT_DIR/refs/heads` and `$GIT_DIR/refs/tags`
+directories or, as entries in file `$GIT_DIR/packed-refs`
+if refs are packed by `git gc`).
+
+git imposes the following rules on how references are named:
. They can include slash `/` for hierarchical (directory)
grouping, but no slash-separated component can begin with a
- dot `.`.
+ dot `.` or end with the sequence `.lock`.
+
+. They must contain at least one `/`. This enforces the presence of a
+ category like `heads/`, `tags/` etc. but the actual names are not
+ restricted. If the `--allow-onelevel` option is used, this rule
+ is waived.
. They cannot have two consecutive dots `..` anywhere.
. They cannot have ASCII control characters (i.e. bytes whose
values are lower than \040, or \177 `DEL`), space, tilde `~`,
- caret `{caret}`, colon `:`, question-mark `?`, asterisk `*`,
- or open bracket `[` anywhere.
+ caret `{caret}`, or colon `:` anywhere.
-. They cannot end with a slash `/` nor a dot `.`.
+. They cannot have question-mark `?`, asterisk `{asterisk}`, or open
+ bracket `[` anywhere. See the `--refspec-pattern` option below for
+ an exception to this rule.
-. They cannot end with the sequence `.lock`.
+. They cannot begin or end with a slash `/` or contain multiple
+ consecutive slashes (see the `--normalize` option below for an
+ exception to this rule)
+
+. They cannot end with a dot `.`.
. They cannot contain a sequence `@{`.
+. They cannot contain a `\`.
+
These rules make it easy for shell script based tools to parse
reference names, pathname expansion by the shell when a reference name is used
unquoted (by mistake), and also avoids ambiguities in certain
-reference name expressions (see linkgit:git-rev-parse[1]):
+reference name expressions (see linkgit:gitrevisions[7]):
. A double-dot `..` is often used as in `ref1..ref2`, and in some
contexts this notation means `{caret}ref1 ref2` (i.e. not in
. A colon `:` is used as in `srcref:dstref` to mean "use srcref\'s
value and store it in dstref" in fetch and push operations.
It may also be used to select a specific object such as with
- 'git-cat-file': "git cat-file blob v1.3.3:refs.c".
+ 'git cat-file': "git cat-file blob v1.3.3:refs.c".
. at-open-brace `@{` is used as a notation to access a reflog entry.
-With the `--branch` option, it expands a branch name shorthand and
-prints the name of the branch the shorthand refers to.
+With the `--branch` option, it expands the ``previous branch syntax''
+`@{-n}`. For example, `@{-1}` is a way to refer the last branch you
+were on. This option should be used by porcelains to accept this
+syntax anywhere a branch name is expected, so they can act as if you
+typed the branch name.
-EXAMPLE
+OPTIONS
-------
+--allow-onelevel::
+--no-allow-onelevel::
+ Controls whether one-level refnames are accepted (i.e.,
+ refnames that do not contain multiple `/`-separated
+ components). The default is `--no-allow-onelevel`.
+
+--refspec-pattern::
+ Interpret <refname> as a reference name pattern for a refspec
+ (as used with remote repositories). If this option is
+ enabled, <refname> is allowed to contain a single `{asterisk}`
+ in place of a one full pathname component (e.g.,
+ `foo/{asterisk}/bar` but not `foo/bar{asterisk}`).
+
+--normalize::
+ Normalize 'refname' by removing any leading slash (`/`)
+ characters and collapsing runs of adjacent slashes between
+ name components into a single slash. Iff the normalized
+ refname is valid then print it to standard output and exit
+ with a status of 0. (`--print` is a deprecated way to spell
+ `--normalize`.)
+
+
+EXAMPLES
+--------
-git check-ref-format --branch @{-1}::
-
-Print the name of the previous branch.
-
+* Print the name of the previous branch:
++
+------------
+$ git check-ref-format --branch @{-1}
+------------
+
+* Determine the reference name to use for a new branch:
++
+------------
+$ ref=$(git check-ref-format --normalize "refs/heads/$newbranch") ||
+die "we do not like '$newbranch' as a branch name."
+------------
GIT
---