Git hooks - to go in .git/hooks/

commit-msg

#!/bin/sh

if diff "$1" "$1.tmp" > /dev/null; then
    echo >&2 Aborting commit due to unchanged commit message.
    rm "$1.tmp"
    exit 1
else
    rm "$1.tmp"
fi

prepare-commit-msg

#!/usr/bin/perl
#
# Pre-commit hook to look at the current branch, see if it starts with a
#  number followed by - or _, and if so use that number to start the first
#  line of the commit message with "Bug (number) : ".

use warnings;
use strict;

my ($filename, $source, $SHA1) = @ARGV;
# $source theoretically gives info on whether this is a merge commit, etc. 
# I haven't done anything with this, but probably should. See "git help hooks" for 
# full info.

unless ($filename) {
    print "No filename";
    exit 0;
}

my $branchname = `git symbolic-ref --short -q HEAD`;
exit 0 unless $branchname;

my $bugnumber = undef;

if ( $branchname =~ /^([0-9]+)[-|_]/ ) {
    $bugnumber = $1;
}

exit 0 unless $bugnumber;

exit 0 unless open( FILE, "< $filename" );
my @lines = <FILE>;
close( FILE );

exit 0 unless open( FILE, "> $filename" );
print FILE "(Bug $bugnumber) : ";
print FILE @lines;
close( FILE );

#copy the original file to a temporary one so that we can compare the two
# in the commit-msg hook to see if unchanged - if unchanged, should
# abort commit.
my $tmpfilename = $filename . ".tmp";
system( "cp $filename $tmpfilename\n" );