Merge branch 'maint'

[git.git] / Documentation / git-check-ref-format.txt

diff --git a/Documentation/git-check-ref-format.txt b/Documentation/git-check-ref-format.txt
index 171b68377d6604167fde4f5e4266432fa9048345..0aeef24780f07e5d5fa021f6ebdaa7090a3dcdb7 100644 (file)
--- a/Documentation/git-check-ref-format.txt
+++ b/Documentation/git-check-ref-format.txt
@@ -7,7 +7,10 @@ git-check-ref-format - Ensures that a reference name is well formed
 
 SYNOPSIS
 --------
+[verse]
 'git check-ref-format' <refname>
+'git check-ref-format' --print <refname>
+'git check-ref-format' --branch <branchname-shorthand>
 
 DESCRIPTION
 -----------
@@ -23,6 +26,10 @@ imposes the following rules on how references are named:
   grouping, but no slash-separated component can begin with a
   dot `.`.
 
+. They must contain at least one `/`. This enforces the presence of a
+  category like `heads/`, `tags/` etc. but the actual names are not
+  restricted.
+
 . They cannot have two consecutive dots `..` anywhere.
 
 . They cannot have ASCII control characters (i.e. bytes whose
@@ -30,7 +37,13 @@ imposes the following rules on how references are named:
   caret `{caret}`, colon `:`, question-mark `?`, asterisk `*`,
   or open bracket `[` anywhere.
 
-. They cannot end with a slash `/`.
+. They cannot end with a slash `/` nor a dot `.`.
+
+. They cannot end with the sequence `.lock`.
+
+. They cannot contain a sequence `@{`.
+
+- They cannot contain a `\\`.
 
 These rules make it easy for shell script based tools to parse
 reference names, pathname expansion by the shell when a reference name is used
@@ -49,6 +62,33 @@ reference name expressions (see linkgit:git-rev-parse[1]):
   It may also be used to select a specific object such as with
   'git-cat-file': "git cat-file blob v1.3.3:refs.c".
 
+. at-open-brace `@{` is used as a notation to access a reflog entry.
+
+With the `--print` option, if 'refname' is acceptable, it prints the
+canonicalized name of a hypothetical reference with that name.  That is,
+it prints 'refname' with any extra `/` characters removed.
+
+With the `--branch` option, it expands the ``previous branch syntax''
+`@{-n}`.  For example, `@{-1}` is a way to refer the last branch you
+were on.  This option should be used by porcelains to accept this
+syntax anywhere a branch name is expected, so they can act as if you
+typed the branch name.
+
+EXAMPLES
+--------
+
+* Print the name of the previous branch:
++
+------------
+$ git check-ref-format --branch @{-1}
+------------
+
+* Determine the reference name to use for a new branch:
++
+------------
+$ ref=$(git check-ref-format --print "refs/heads/$newbranch") ||
+die "we do not like '$newbranch' as a branch name."
+------------
 
 GIT
 ---