'\" t
.\"     Title: git-check-ref-format
.\"    Author: [FIXME: author] [see http://www.docbook.org/tdg5/en/html/author]
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 2024-04-29
.\"    Manual: Git Manual
.\"    Source: Git 2.45.0
.\"  Language: English
.\"
.TH "GIT\-CHECK\-REF\-FORMAT" "1" "2024\-04\-29" "Git 2\&.45\&.0" "Git Manual"
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.SH "NAME"
git-check-ref-format \- Ensures that a reference name is well formed
.SH "SYNOPSIS"
.sp
.nf
\fIgit check\-ref\-format\fR [\-\-normalize]
       [\-\-[no\-]allow\-onelevel] [\-\-refspec\-pattern]
       <refname>
\fIgit check\-ref\-format\fR \-\-branch <branchname\-shorthand>
.fi
.sp
.SH "DESCRIPTION"
.sp
Checks if a given \fIrefname\fR is acceptable, and exits with a non\-zero status if it is not\&.
.sp
A reference is used in Git to specify branches and tags\&. A branch head is stored in the \fBrefs/heads\fR hierarchy, while a tag is stored in the \fBrefs/tags\fR hierarchy of the ref namespace (typically in \fB$GIT_DIR/refs/heads\fR and \fB$GIT_DIR/refs/tags\fR directories or, as entries in file \fB$GIT_DIR/packed\-refs\fR if refs are packed by \fBgit gc\fR)\&.
.sp
Git imposes the following rules on how references are named:
.sp
.RS 4
.ie n \{\
\h'-04' 1.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  1." 4.2
.\}
They can include slash
\fB/\fR
for hierarchical (directory) grouping, but no slash\-separated component can begin with a dot
\fB\&.\fR
or end with the sequence
\fB\&.lock\fR\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04' 2.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  2." 4.2
.\}
They must contain at least one
\fB/\fR\&. This enforces the presence of a category like
\fBheads/\fR,
\fBtags/\fR
etc\&. but the actual names are not restricted\&. If the
\fB\-\-allow\-onelevel\fR
option is used, this rule is waived\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04' 3.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  3." 4.2
.\}
They cannot have two consecutive dots
\fB\&.\&.\fR
anywhere\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04' 4.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  4." 4.2
.\}
They cannot have ASCII control characters (i\&.e\&. bytes whose values are lower than \e040, or \e177
\fBDEL\fR), space, tilde
\fB~\fR, caret
\fB^\fR, or colon
\fB:\fR
anywhere\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04' 5.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  5." 4.2
.\}
They cannot have question\-mark
\fB?\fR, asterisk
\fB*\fR, or open bracket
\fB[\fR
anywhere\&. See the
\fB\-\-refspec\-pattern\fR
option below for an exception to this rule\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04' 6.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  6." 4.2
.\}
They cannot begin or end with a slash
\fB/\fR
or contain multiple consecutive slashes (see the
\fB\-\-normalize\fR
option below for an exception to this rule)\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04' 7.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  7." 4.2
.\}
They cannot end with a dot
\fB\&.\fR\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04' 8.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  8." 4.2
.\}
They cannot contain a sequence
\fB@{\fR\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04' 9.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  9." 4.2
.\}
They cannot be the single character
\fB@\fR\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04'10.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "10." 4.2
.\}
They cannot contain a
\fB\e\fR\&.
.RE
.sp
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 unquoted (by mistake), and also avoid ambiguities in certain reference name expressions (see \fBgitrevisions\fR(7)):
.sp
.RS 4
.ie n \{\
\h'-04' 1.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  1." 4.2
.\}
A double\-dot
\fB\&.\&.\fR
is often used as in
\fBref1\&.\&.ref2\fR, and in some contexts this notation means
\fB^ref1 ref2\fR
(i\&.e\&. not in
\fBref1\fR
and in
\fBref2\fR)\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04' 2.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  2." 4.2
.\}
A tilde
\fB~\fR
and caret
\fB^\fR
are used to introduce the postfix
\fInth parent\fR
and
\fIpeel onion\fR
operation\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04' 3.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  3." 4.2
.\}
A colon
\fB:\fR
is used as in
\fBsrcref:dstref\fR
to mean "use srcref\(cqs value and store it in dstref" in fetch and push operations\&. It may also be used to select a specific object such as with
\fIgit cat\-file\fR: "git cat\-file blob v1\&.3\&.3:refs\&.c"\&.
.RE
.sp
.RS 4
.ie n \{\
\h'-04' 4.\h'+01'\c
.\}
.el \{\
.sp -1
.IP "  4." 4.2
.\}
at\-open\-brace
\fB@{\fR
is used as a notation to access a reflog entry\&.
.RE
.sp
With the \fB\-\-branch\fR option, the command takes a name and checks if it can be used as a valid branch name (e\&.g\&. when creating a new branch)\&. But be cautious when using the previous checkout syntax that may refer to a detached HEAD state\&. The rule \fBgit check\-ref\-format \-\-branch $name\fR implements may be stricter than what \fBgit check\-ref\-format refs/heads/$name\fR says (e\&.g\&. a dash may appear at the beginning of a ref component, but it is explicitly forbidden at the beginning of a branch name)\&. When run with the \fB\-\-branch\fR option in a repository, the input is first expanded for the \(lqprevious checkout syntax\(rq \fB@{\-n}\fR\&. For example, \fB@{\-1}\fR is a way to refer the last thing that was checked out using "git switch" or "git checkout" operation\&. 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\&. As an exception note that, the \(lqprevious checkout operation\(rq might result in a commit object name when the N\-th last thing checked out was not a branch\&.
.SH "OPTIONS"
.PP
\-\-[no\-]allow\-onelevel
.RS 4
Controls whether one\-level refnames are accepted (i\&.e\&., refnames that do not contain multiple
\fB/\fR\-separated components)\&. The default is
\fB\-\-no\-allow\-onelevel\fR\&.
.RE
.PP
\-\-refspec\-pattern
.RS 4
Interpret <refname> as a reference name pattern for a refspec (as used with remote repositories)\&. If this option is enabled, <refname> is allowed to contain a single
\fB*\fR
in the refspec (e\&.g\&.,
\fBfoo/bar*/baz\fR
or
\fBfoo/bar*baz/\fR
but not
\fBfoo/bar*/baz*\fR)\&.
.RE
.PP
\-\-normalize
.RS 4
Normalize
\fIrefname\fR
by removing any leading slash (\fB/\fR) characters and collapsing runs of adjacent slashes between name components into a single slash\&. If the normalized refname is valid then print it to standard output and exit with a status of 0, otherwise exit with a non\-zero status\&. (\fB\-\-print\fR
is a deprecated way to spell
\fB\-\-normalize\fR\&.)
.RE
.SH "EXAMPLES"
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Print the name of the previous thing checked out:
.sp
.if n \{\
.RS 4
.\}
.nf
$ git check\-ref\-format \-\-branch @{\-1}
.fi
.if n \{\
.RE
.\}
.sp
.RE
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
Determine the reference name to use for a new branch:
.sp
.if n \{\
.RS 4
.\}
.nf
$ ref=$(git check\-ref\-format \-\-normalize "refs/heads/$newbranch")||
{ echo "we do not like \*(Aq$newbranch\*(Aq as a branch name\&." >&2 ; exit 1 ; }
.fi
.if n \{\
.RE
.\}
.sp
.RE
.SH "GIT"
.sp
Part of the \fBgit\fR(1) suite