Documentation/git-check-ref-format.txt

   1 git-check-ref-format(1)
   2 =======================
   3
   4 NAME
   5 ----
   6 git-check-ref-format - Ensures that a reference name is well formed
   7
   8 SYNOPSIS
   9 --------
  10 [verse]
  11 'git check-ref-format' [--normalize]
  12        [--[no-]allow-onelevel] [--refspec-pattern]
  13        <refname>
  14 'git check-ref-format' --branch <branchname-shorthand>
  15
  16 DESCRIPTION
  17 -----------
  18 Checks if a given 'refname' is acceptable, and exits with a non-zero
  19 status if it is not.
  20
  21 A reference is used in Git to specify branches and tags.  A
  22 branch head is stored in the `refs/heads` hierarchy, while
  23 a tag is stored in the `refs/tags` hierarchy of the ref namespace
  24 (typically in `$GIT_DIR/refs/heads` and `$GIT_DIR/refs/tags`
  25 directories or, as entries in file `$GIT_DIR/packed-refs`
  26 if refs are packed by `git gc`).
  27
  28 Git imposes the following rules on how references are named:
  29
  30 . They can include slash `/` for hierarchical (directory)
  31   grouping, but no slash-separated component can begin with a
  32   dot `.` or end with the sequence `.lock`.
  33
  34 . They must contain at least one `/`. This enforces the presence of a
  35   category like `heads/`, `tags/` etc. but the actual names are not
  36   restricted.  If the `--allow-onelevel` option is used, this rule
  37   is waived.
  38
  39 . They cannot have two consecutive dots `..` anywhere.
  40
  41 . They cannot have ASCII control characters (i.e. bytes whose
  42   values are lower than \040, or \177 `DEL`), space, tilde `~`,
  43   caret `^`, or colon `:` anywhere.
  44
  45 . They cannot have question-mark `?`, asterisk `*`, or open
  46   bracket `[` anywhere.  See the `--refspec-pattern` option below for
  47   an exception to this rule.
  48
  49 . They cannot begin or end with a slash `/` or contain multiple
  50   consecutive slashes (see the `--normalize` option below for an
  51   exception to this rule)
  52
  53 . They cannot end with a dot `.`.
  54
  55 . They cannot contain a sequence `@{`.
  56
  57 . They cannot be the single character `@`.
  58
  59 . They cannot contain a `\`.
  60
  61 These rules make it easy for shell script based tools to parse
  62 reference names, pathname expansion by the shell when a reference name is used
  63 unquoted (by mistake), and also avoids ambiguities in certain
  64 reference name expressions (see linkgit:gitrevisions[7]):
  65
  66 . A double-dot `..` is often used as in `ref1..ref2`, and in some
  67   contexts this notation means `^ref1 ref2` (i.e. not in
  68   `ref1` and in `ref2`).
  69
  70 . A tilde `~` and caret `^` are used to introduce the postfix
  71   'nth parent' and 'peel onion' operation.
  72
  73 . A colon `:` is used as in `srcref:dstref` to mean "use srcref\'s
  74   value and store it in dstref" in fetch and push operations.
  75   It may also be used to select a specific object such as with
  76   'git cat-file': "git cat-file blob v1.3.3:refs.c".
  77
  78 . at-open-brace `@{` is used as a notation to access a reflog entry.
  79
  80 With the `--branch` option, it expands the ``previous branch syntax''
  81 `@{-n}`.  For example, `@{-1}` is a way to refer the last branch you
  82 were on.  This option should be used by porcelains to accept this
  83 syntax anywhere a branch name is expected, so they can act as if you
  84 typed the branch name.
  85
  86 OPTIONS
  87 -------
  88 --[no-]allow-onelevel::
  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`.
  92
  93 --refspec-pattern::
  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 `*`
  97         in place of a one full pathname component (e.g.,
  98         `foo/*/bar` but not `foo/bar*`).
  99
 100 --normalize::
 101         Normalize 'refname' by removing any leading slash (`/`)
 102         characters and collapsing runs of adjacent slashes between
 103         name components into a single slash.  Iff the normalized
 104         refname is valid then print it to standard output and exit
 105         with a status of 0.  (`--print` is a deprecated way to spell
 106         `--normalize`.)
 107
 108
 109 EXAMPLES
 110 --------
 111
 112 * Print the name of the previous branch:
 113 +
 114 ------------
 115 $ git check-ref-format --branch @{-1}
 116 ------------
 117
 118 * Determine the reference name to use for a new branch:
 119 +
 120 ------------
 121 $ ref=$(git check-ref-format --normalize "refs/heads/$newbranch") ||
 122 die "we do not like '$newbranch' as a branch name."
 123 ------------
 124
 125 GIT
 126 ---
 127 Part of the linkgit:git[1] suite