check_pid.pl is a small check plugin for Nagios (www.nagios.org). It checks the existence of a file. In this case, it is used for PID files. It can be used in two ways: check if a PID file exists or check if a PID file does NOT exist.

Usage
check, if the SSH pid file exists and returns OK.
$ check_pid -f /var/run/sshd.pid

checks, if the rsnapshot (backup process) is still running and returns CRITICAL.
$ check_pid -e -f /var/run/rsnapshot.pid

Download
2008-06-24: Version 0.2

License
GNU public license (http://www.gnu.org/licenses/gpl.html)