Monitor Directory for Changes

Here’s a simple script that I setup for my development WSGI server to reload itself once changes in source code are detected:

#!/bin/bash

while true; do
    A=`find $1 -printf '%t' | md5sum`;
    sleep 1
    B=`find $1 -printf '%t' | md5sum`;
    if [ "$A" != "$B" ]; then
        echo "Detected change, doing: $2"
        eval $2
    fi
done

It’s very simple (a poor-man’s replacement for inotify) and doesn’t do anything complicated. Usage ./monitor.sh application "my-reload-services.sh". You can filter out unwanted stuff like maybe *.swp files by referring to the man find pages.

What do you use to monitor for changes? How can the above script be improved?