9114751966aa31d1ff233077d53ff98a7c4c70fa
   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