GIT-CHECK-REF-FOR(1)             Git Manual             GIT-CHECK-REF-FOR(1)

NAME         top

       git-check-ref-format - Ensures that a reference name is well formed

SYNOPSIS         top

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

DESCRIPTION         top

       Checks if a given refname is acceptable, and exits with a non-zero
       status if it is not.

       A reference is used in Git to specify branches and tags. A 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:

        1. They can include slash / for hierarchical (directory) grouping,
           but no slash-separated component can begin with a dot .  or end
           with the sequence .lock.

        2. 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

        3. They cannot have two consecutive dots ..  anywhere.

        4. They cannot have ASCII control characters (i.e. bytes whose
           values are lower than \040, or \177 DEL), space, tilde ~, caret
           ^, or colon : anywhere.

        5. They cannot have question-mark ?, asterisk *, or open bracket [
           anywhere. See the --refspec-pattern option below for an exception
           to this rule.

        6. They cannot begin or end with a slash / or contain multiple
           consecutive slashes (see the --normalize option below for an
           exception to this rule)

        7. They cannot end with a dot ..

        8. They cannot contain a sequence @{.

        9. They cannot be the single character @.

       10. 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 avoid ambiguities in
       certain reference name expressions (see gitrevisions(7)):

        1. 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

        2. A tilde ~ and caret ^ are used to introduce the postfix nth
           parent and peel onion operation.

        3. 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".

        4. 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 “previous checkout
       syntax” @{-n}. For example, @{-1} is a way to refer the last thing
       that was checked out using "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 “previous checkout operation” might
       result in a commit object name when the N-th last thing checked out
       was not a branch.

OPTIONS         top

           Controls whether one-level refnames are accepted (i.e., refnames
           that do not contain multiple /-separated components). The default
           is --no-allow-onelevel.

           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 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         top

       ·   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 '$newbranch' as a branch name." >&2 ; exit 1 ; }

GIT         top

       Part of the git(1) suite

COLOPHON         top

       This page is part of the git (Git distributed version control system)
       project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual page,
       see ⟨⟩.  This page was obtained from the
       project's upstream Git repository ⟨⟩ on
       2018-02-02.  (At that time, the date of the most recent commit that
       was found in the repository was 2018-01-23.)  If you discover any
       rendering problems in this HTML version of the page, or you believe
       there is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

Git           01/23/2018             GIT-CHECK-REF-FOR(1)

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