Merge git://git.kernel.org/pub/scm/gitk/gitk
[git/git.git] / Documentation / git-check-ref-format.txt
1 git-check-ref-format(1)
2 =======================
3
4 NAME
5 ----
6 git-check-ref-format - Make sure ref name is well formed.
7
8 SYNOPSIS
9 --------
10 'git-check-ref-format' <refname>
11
12 DESCRIPTION
13 -----------
14 Checks if a given 'refname' is acceptable, and exits non-zero if
15 it is not.
16
17 A reference is used in git to specify branches and tags. A
18 branch head is stored under `$GIT_DIR/refs/heads` directory, and
19 a tag is stored under `$GIT_DIR/refs/tags` directory. git
20 imposes the following rules on how refs are named:
21
22 . It could be named hierarchically (i.e. separated with slash
23 `/`), but each of its component cannot begin with a dot `.`;
24
25 . It cannot have two consecutive dots `..` anywhere;
26
27 . It cannot have ASCII control character (i.e. bytes whose
28 values are lower than \040, or \177 `DEL`), space, tilde `~`,
29 caret `{caret}`, colon `:`, question-mark `?`, asterisk `*`,
30 or open bracket `[` anywhere;
31
32 . It cannot end with a slash `/`.
33
34 These rules makes it easy for shell script based tools to parse
35 refnames, pathname expansion by the shell when a refname is used
36 unquoted (by mistake), and also avoids ambiguities in certain
37 refname expressions (see gitlink:git-rev-parse[1]). Namely:
38
39 . double-dot `..` are often used as in `ref1..ref2`, and in some
40 context this notation means `{caret}ref1 ref2` (i.e. not in
41 ref1 and in ref2).
42
43 . tilde `~` and caret `{caret}` are used to introduce postfix
44 'nth parent' and 'peel onion' operation.
45
46 . colon `:` is used as in `srcref:dstref` to mean "use srcref\'s
47 value and store it in dstref" in fetch and push operations.
48
49
50 GIT
51 ---
52 Part of the gitlink:git[7] suite