git-check-ref-format(1) Manual Page

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 could be named hierarchically (i.e. separated with slash /), but each of its component cannot 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 ^, 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 ^ref1 ref2 (i.e. not in ref1 and in ref2).

2. tilde ~ and 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.

Part of the git(7) suite