1git-check-ref-format(1) 2======================= 3 4NAME 5---- 6git-check-ref-format - Ensures that a reference name is well formed 7 8SYNOPSIS 9-------- 10[verse] 11'git check-ref-format' [--print] 12 [--[no-]allow-onelevel] [--refspec-pattern] <refname> 13'git check-ref-format' --branch <branchname-shorthand> 14 15DESCRIPTION 16----------- 17Checks if a given 'refname' is acceptable, and exits with a non-zero 18status if it is not. 19 20A reference is used in git to specify branches and tags. A 21branch head is stored in the `refs/heads` hierarchy, while 22a tag is stored in the `refs/tags` hierarchy of the ref namespace 23(typically in `$GIT_DIR/refs/heads` and `$GIT_DIR/refs/tags` 24directories or, as entries in file `$GIT_DIR/packed-refs` 25if refs are packed by `git gc`). 26 27git imposes the following rules on how references are named: 28 29. They can include slash `/` for hierarchical (directory) 30 grouping, but no slash-separated component can begin with a 31 dot `.` or end with the sequence `.lock`. 32 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 36 is waived. 37 38. They cannot have two consecutive dots `..` anywhere. 39 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. 43 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. 47 48. They cannot end with a slash `/` nor a dot `.`. 49 50. They cannot contain a sequence `@{`. 51 52. They cannot contain a `\`. 53 54These rules make it easy for shell script based tools to parse 55reference names, pathname expansion by the shell when a reference name is used 56unquoted (by mistake), and also avoids ambiguities in certain 57reference name expressions (see linkgit:gitrevisions[7]): 58 59. A double-dot `..` is often used as in `ref1..ref2`, and in some 60 contexts this notation means `{caret}ref1 ref2` (i.e. not in 61 `ref1` and in `ref2`). 62 63. A tilde `~` and caret `{caret}` are used to introduce the postfix 64 'nth parent' and 'peel onion' operation. 65 66. A colon `:` is used as in `srcref:dstref` to mean "use srcref\'s 67 value and store it in dstref" in fetch and push operations. 68 It may also be used to select a specific object such as with 69 'git cat-file': "git cat-file blob v1.3.3:refs.c". 70 71. at-open-brace `@{` is used as a notation to access a reflog entry. 72 73With the `--print` option, if 'refname' is acceptable, it prints the 74canonicalized name of a hypothetical reference with that name. That is, 75it prints 'refname' with any extra `/` characters removed. 76 77With the `--branch` option, it expands the ``previous branch syntax'' 78`@{-n}`. For example, `@{-1}` is a way to refer the last branch you 79were on. This option should be used by porcelains to accept this 80syntax anywhere a branch name is expected, so they can act as if you 81typed the branch name. 82 83OPTIONS 84------- 85--allow-onelevel:: 86--no-allow-onelevel:: 87 Controls whether one-level refnames are accepted (i.e., 88 refnames that do not contain multiple `/`-separated 89 components). The default is `--no-allow-onelevel`. 90 91--refspec-pattern:: 92 Interpret <refname> as a reference name pattern for a refspec 93 (as used with remote repositories). If this option is 94 enabled, <refname> is allowed to contain a single `{asterisk}` 95 in place of a one full pathname component (e.g., 96 `foo/{asterisk}/bar` but not `foo/bar{asterisk}`). 97 98EXAMPLES 99-------- 100 101* Print the name of the previous branch: 102+ 103------------ 104$ git check-ref-format --branch @{-1} 105------------ 106 107* Determine the reference name to use for a new branch: 108+ 109------------ 110$ ref=$(git check-ref-format --print "refs/heads/$newbranch") || 111die "we do not like '$newbranch' as a branch name." 112------------ 113 114GIT 115--- 116Part of the linkgit:git[1] suite