1 git-check-ref-format(1)
2 =======================
6 git-check-ref-format - Ensures that a reference name is well formed
11 'git check-ref-format' [--print]
12 [--[no-]allow-onelevel] [--refspec-pattern] <refname>
13 'git check-ref-format' --branch <branchname-shorthand>
17 Checks if a given 'refname' is acceptable, and exits with a non-zero
20 A reference is used in git to specify branches and tags. A
21 branch head is stored in the `refs/heads` hierarchy, while
22 a tag is stored in the `refs/tags` hierarchy of the ref namespace
23 (typically in `$GIT_DIR/refs/heads` and `$GIT_DIR/refs/tags`
24 directories or, as entries in file `$GIT_DIR/packed-refs`
25 if refs are packed by `git gc`).
27 git imposes the following rules on how references are named:
29 . They can include slash `/` for hierarchical (directory)
30 grouping, but no slash-separated component can begin with a
33 . They must contain at least one `/`. This enforces the presence of a
34 category like `heads/`, `tags/` etc. but the actual names are not
35 restricted. If the `--allow-onelevel` option is used, this rule
38 . They cannot have two consecutive dots `..` anywhere.
40 . They cannot have ASCII control characters (i.e. bytes whose
41 values are lower than \040, or \177 `DEL`), space, tilde `~`,
42 caret `{caret}`, or colon `:` anywhere.
44 . They cannot have question-mark `?`, asterisk `{asterisk}`, or open
45 bracket `[` anywhere. See the `--refspec-pattern` option below for
46 an exception to this rule.
48 . They cannot end with a slash `/` nor a dot `.`.
50 . They cannot end with the sequence `.lock`.
52 . They cannot contain a sequence `@{`.
54 . They cannot contain a `\`.
56 These rules make it easy for shell script based tools to parse
57 reference names, pathname expansion by the shell when a reference name is used
58 unquoted (by mistake), and also avoids ambiguities in certain
59 reference name expressions (see linkgit:gitrevisions[7]):
61 . A double-dot `..` is often used as in `ref1..ref2`, and in some
62 contexts this notation means `{caret}ref1 ref2` (i.e. not in
63 `ref1` and in `ref2`).
65 . A tilde `~` and caret `{caret}` are used to introduce the postfix
66 'nth parent' and 'peel onion' operation.
68 . A colon `:` is used as in `srcref:dstref` to mean "use srcref\'s
69 value and store it in dstref" in fetch and push operations.
70 It may also be used to select a specific object such as with
71 'git cat-file': "git cat-file blob v1.3.3:refs.c".
73 . at-open-brace `@{` is used as a notation to access a reflog entry.
75 With the `--print` option, if 'refname' is acceptable, it prints the
76 canonicalized name of a hypothetical reference with that name. That is,
77 it prints 'refname' with any extra `/` characters removed.
79 With the `--branch` option, it expands the ``previous branch syntax''
80 `@{-n}`. For example, `@{-1}` is a way to refer the last branch you
81 were on. This option should be used by porcelains to accept this
82 syntax anywhere a branch name is expected, so they can act as if you
83 typed the branch name.
89 Controls whether one-level refnames are accepted (i.e.,
90 refnames that do not contain multiple `/`-separated
91 components). The default is `--no-allow-onelevel`.
94 Interpret <refname> as a reference name pattern for a refspec
95 (as used with remote repositories). If this option is
96 enabled, <refname> is allowed to contain a single `{asterisk}`
97 in place of a one full pathname component (e.g.,
98 `foo/{asterisk}/bar` but not `foo/bar{asterisk}`).
103 * Print the name of the previous branch:
106 $ git check-ref-format --branch @{-1}
109 * Determine the reference name to use for a new branch:
112 $ ref=$(git check-ref-format --print "refs/heads/$newbranch") ||
113 die "we do not like '$newbranch' as a branch name."
118 Part of the linkgit:git[1] suite