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' <refname> 12'git check-ref-format' --branch <branchname-shorthand> 13 14DESCRIPTION 15----------- 16Checks if a given 'refname' is acceptable, and exits with a non-zero 17status if it is not. 18 19A reference is used in git to specify branches and tags. A 20branch head is stored under the `$GIT_DIR/refs/heads` directory, and 21a tag is stored under the `$GIT_DIR/refs/tags` directory. git 22imposes the following rules on how references are named: 23 24. They can include slash `/` for hierarchical (directory) 25 grouping, but no slash-separated component can begin with a 26 dot `.`. 27 28. They must contain at least one `/`. This enforces the presence of a 29 category like `heads/`, `tags/` etc. but the actual names are not 30 restricted. 31 32. They cannot have two consecutive dots `..` anywhere. 33 34. They cannot have ASCII control characters (i.e. bytes whose 35 values are lower than \040, or \177 `DEL`), space, tilde `~`, 36 caret `{caret}`, colon `:`, question-mark `?`, asterisk `*`, 37 or open bracket `[` anywhere. 38 39. They cannot end with a slash `/` nor a dot `.`. 40 41. They cannot end with the sequence `.lock`. 42 43. They cannot contain a sequence `@{`. 44 45- They cannot contain a `\\`. 46 47These rules make it easy for shell script based tools to parse 48reference names, pathname expansion by the shell when a reference name is used 49unquoted (by mistake), and also avoids ambiguities in certain 50reference name expressions (see linkgit:git-rev-parse[1]): 51 52. A double-dot `..` is often used as in `ref1..ref2`, and in some 53 contexts this notation means `{caret}ref1 ref2` (i.e. not in 54 `ref1` and in `ref2`). 55 56. A tilde `~` and caret `{caret}` are used to introduce the postfix 57 'nth parent' and 'peel onion' operation. 58 59. A colon `:` is used as in `srcref:dstref` to mean "use srcref\'s 60 value and store it in dstref" in fetch and push operations. 61 It may also be used to select a specific object such as with 62 'git-cat-file': "git cat-file blob v1.3.3:refs.c". 63 64. at-open-brace `@{` is used as a notation to access a reflog entry. 65 66With the `--branch` option, it expands the ``previous branch syntax'' 67`@{-n}`. For example, `@{-1}` is a way to refer the last branch you 68were on. This option should be used by porcelains to accept this 69syntax anywhere a branch name is expected, so they can act as if you 70typed the branch name. 71 72EXAMPLE 73------- 74 75git check-ref-format --branch @{-1}:: 76 77Print the name of the previous branch. 78 79 80GIT 81--- 82Part of the linkgit:git[1] suite