Inotify provides a nifty C API to monitor files and directories. The API
hooks into your kernel and responding to events on your filesystem is much more
efficient than doing something like writing a cron job to check for changes in a
directory every minute. Fortunately, if you’re not a C developer, there is a
package called inotify-tools that comes with two programs,
inotifywatch. The difference is
inotifywait waits for changes and
inotifywatch gathers filesystem access statistics.