git check-ref-format <refname>


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

A reference is used in git to specify branches and tags. A branch head is stored under $GIT_DIR/refs/heads directory, and a tag is stored under $GIT_DIR/refs/tags directory. git imposes the following rules on how refs are named:

  1. It can include slash / for hierarchical (directory) grouping, but no slash-separated component can begin with a dot .;

  2. It cannot have two consecutive dots .. anywhere;

  3. It cannot have ASCII control character (i.e. bytes whose values are lower than \040, or \177 DEL), space, tilde ~, caret {caret}, colon :, question-mark ?, asterisk *, or open bracket [ anywhere;

  4. It cannot end with a slash /.

These rules makes it easy for shell script based tools to parse refnames, pathname expansion by the shell when a refname is used unquoted (by mistake), and also avoids ambiguities in certain refname expressions (see git-rev-parse(1)). Namely:

  1. double-dot .. are often used as in ref1..ref2, and in some context this notation means {caret}ref1 ref2 (i.e. not in ref1 and in ref2).

  2. tilde ~ and caret {caret} are used to introduce postfix nth parent and peel onion operation.

  3. 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".


Part of the git(1) suite