Git hook that adds "Refs #[issue number]" to commit messages

install.sh

cd project/
cp -i prepare-commit-msg .git/hooks/
chmod +x .git/hooks/prepare-commit-msg

prepare-commit-msg

#!/usr/bin/env perl -w
#
# prepare-commit-msg
#
# Git commit hook that modifies the message of a new commit to write in the
# current issue number if present in the branch name.

use strict;


my $filename = $ARGV[0];
my $commit_mode = $ARGV[1];

# For new regular commits
if (!defined $commit_mode) {
	my $branch_name = `git rev-parse --abbrev-ref HEAD`;
	my @match = $branch_name =~ /^(\d+)-/;
	my $issue_number = $match[0];

	# If the current branch has an initial issue number
	# Write "Refs #<$issue_number>" to the first line of the commit message
	if ($issue_number) {
		open my $f_in, '<:encoding(UTF-8)', $filename;
		open my $f_out, '>:encoding(UTF-8)', "$filename.new";

		print $f_out "\n\nRefs #" . $issue_number;

		while (<$f_in>) {
			print $f_out $_;
		}

		close $f_out;
		close $f_in;

		unlink $filename;
		rename "$filename.new", $filename;
	}
}