System Grab Bag

Name

Synopsis

git check-ref-format [--normalize]
       [--[no-]allow-onelevel] [--refspec-pattern]
       <refname>
git check-ref-format --branch <branchname-shorthand>

Description

They can include slash / for hierarchical (directory) grouping, but no slash-separated component can begin with a dot . or end with the sequence .lock. \h'-04' 2.\h'+01'\c

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. \h'-04' 3.\h'+01'\c

They cannot have two consecutive dots .. anywhere. \h'-04' 4.\h'+01'\c

They cannot have ASCII control characters (i.e. bytes whose values are lower than \e040, or \e177 DEL), space, tilde ~, caret ^, or colon : anywhere. \h'-04' 5.\h'+01'\c

They cannot have question-mark ?, asterisk *, or open bracket [ anywhere. See the --refspec-pattern option below for an exception to this rule. \h'-04' 6.\h'+01'\c

They cannot begin or end with a slash / or contain multiple consecutive slashes (see the --normalize option below for an exception to this rule) \h'-04' 7.\h'+01'\c

They cannot end with a dot .. \h'-04' 8.\h'+01'\c

They cannot contain a sequence @{. \h'-04' 9.\h'+01'\c

They cannot be the single character @. \h'-04'10.\h'+01'\c

They cannot contain a \e. 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 avoid ambiguities in certain reference name expressions (see gitrevisions(7)): \h'-04' 1.\h'+01'\c

A double-dot .. is often used as in ref1..ref2, and in some contexts this notation means ^ref1 ref2 (i.e. not in ref1 and in ref2). \h'-04' 2.\h'+01'\c

A tilde ~ and caret ^ are used to introduce the postfix nth parent and peel onion operation. \h'-04' 3.\h'+01'\c

A colon : is used as in srcref:dstref to mean "use srcref\(cqs 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". \h'-04' 4.\h'+01'\c

at-open-brace @{ is used as a notation to access a reflog entry. With the --branch option, the command takes a name and checks if it can be used as a valid branch name (e.g. when creating a new branch). But be cautious when using the previous checkout syntax that may refer to a detached HEAD state. The rule git check-ref-format --branch $name implements may be stricter than what git check-ref-format refs/heads/$name says (e.g. a dash may appear at the beginning of a ref component, but it is explicitly forbidden at the beginning of a branch name). When run with --branch option in a repository, the input is first expanded for the \(lqprevious checkout syntax\(rq @{-n}. For example, @{-1} is a way to refer the last thing that was checked out using "git switch" or "git checkout" operation. 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. As an exception note that, the \(lqprevious checkout operation\(rq might result in a commit object name when the N-th last thing checked out was not a branch.

Options

--[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 * in the refspec (e.g., foo/bar*/baz or foo/bar*baz/ but not foo/bar*/baz*).

--normalize Normalize refname by removing any leading slash (/) characters and collapsing runs of adjacent slashes between name components into a single slash. If the normalized refname is valid then print it to standard output and exit with a status of 0, otherwise exit with a non-zero status. (--print is a deprecated way to spell --normalize.)

Examples

Print the name of the previous thing checked out:

$ 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")||
{ echo "we do not like \*(Aq$newbranch\*(Aq as a branch name." >&2 ; exit 1 ; }

Git