git/Documentation/git-symbolic-ref.txt

git-symbolic-ref(1)
===================

NAME
----
git-symbolic-ref - read and modify symbolic refs

SYNOPSIS
--------
'git-symbolic-ref' <name> [<ref>]

DESCRIPTION
-----------
Given one argument, reads which branch head the given symbolic
ref refers to and outputs its path, relative to the `.git/`
directory.  Typically you would give `HEAD` as the <name>
argument to see on which branch your working tree is on.

Give two arguments, create or update a symbolic ref <name> to
point at the given branch <ref>.

Traditionally, `.git/HEAD` is a symlink pointing at
`refs/heads/master`.  When we want to switch to another branch,
we did `ln -sf refs/heads/newbranch .git/HEAD`, and when we want
to find out which branch we are on, we did `readlink .git/HEAD`.
This was fine, and internally that is what still happens by
default, but on platforms that do not have working symlinks,
or that do not have the `readlink(1)` command, this was a bit
cumbersome.  On some platforms, `ln -sf` does not even work as
advertised (horrors).

A symbolic ref can be a regular file that stores a string that
begins with `ref: refs/`.  For example, your `.git/HEAD` *can*
be a regular file whose contents is `ref: refs/heads/master`.
This can be used on a filesystem that does not support symbolic
links.  Instead of doing `readlink .git/HEAD`, `git-symbolic-ref
HEAD` can be used to find out which branch we are on.  To point
the HEAD to `newbranch`, instead of `ln -sf refs/heads/newbranch
.git/HEAD`, `git-symbolic-ref HEAD refs/heads/newbranch` can be
used.

Currently, .git/HEAD uses a regular file symbolic ref on Cygwin,
and everywhere else it is implemented as a symlink.  This can be
changed at compilation time.

Author
------
Written by Junio C Hamano <junkio@cox.net>

GIT
---
Part of the gitlink:git[7] suite