Good but I needed some enhancements

It works but I needed to make some enhancements.
Not sure how updates on NagiosExchange works so I’ll mention them here.

Removed dependacy on /usr/bin/basename

PROGNAME=$0
PROGPATH=${PROGNAME%/*}
PROGNAME=${PROGNAME##*/}

Replaced -ge by -gt to allow warning/error for 0 files on directories that should be empty.