Mutex locking with bash

gistfile1.sh

unset $LOCKED
LOCKFILE="/tmp/lockfile"
function waitlock
{
	while [ -d "$LOCKFILE" ]; do
		sleep 10
	done
}

function lock
{
	echo "Attemping to get a lock on $LOCKFILE"
	mkdir "$LOCKFILE" && LOCKED=1
}

# Mutex locking bash style
while [ ! $LOCKED ]; do
	waitlock()
	lock()
done