git-prompt-helper

#!/usr/bin/env perl
# 
# Git prompt helper
#
# Make your bash prompt with current branch and a dirty flag if
# you have uncommitted stuff.
#
# Author: Michael Zedeler <michael@zedeler.dk>
#
# How to use:
# 
# - Place this script in a bin folder somewhere (lets just call it <bin>).
# - Add this to your .bashrc:
#
#   PS1="\$(<bin>/git-prompt-helper)"$PS1 
# 
# Yes - this affects how fast bash responds.
# On my system it takes around 40ms.
#

use strict;
use warnings;

open my $IN, 'git status 2>/dev/null|';
my $branch;
my $clean;
while(<$IN>) {
	$branch = $1 if /On branch (\S+)/;
	$clean  = 1 if /nothing to commit/;
}
$clean = 0 if not $clean and $branch;
print $branch ? ('[', $branch, ($clean ? '' : '*'), ']') : '';

# Copyright (c) 2010, Michael Zedeler
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without 
# modification, are permitted provided that the following conditions are met:
# 
#     * Redistributions of source code must retain the above copyright 
#       notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above copyright 
#       notice, this list of conditions and the following disclaimer in the 
#       documentation and/or other materials provided with the distribution.
#     * Neither the name of the Michael Zedeler nor the names of its 
#       contributors may be used to endorse or promote products derived from 
#       this software without specific prior written permission.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
# POSSIBILITY OF SUCH DAMAGE.