This module associates a PID file with your script for the purpose
of keeping more than one copy from running (concurrency prevention).
It creates the PID file, checks for its existence when the script
is run, terminates the script if there is already an instance running,
and removes the PID file when the script finishes.

This module's objective is to provide a completely simplified
interface that makes adding PID-file-based concurrency prevention
to your script as quick and simple as possible; hence File::Pid::Quick.
For a more nuanced implementation of PID files, please see File::Pid.

WWW: http://search.cpan.org/dist/File-Pid-Quick/