Using inotify-tools to watch a directory and take action

The inotify-tools can be used to watch a directory or file for activity and take an action when a file is changed, added, edited or simply read. You can find a workaround (or call it solution) for the absence of the inotify-tools in the repositories here.
Sometimes, for various reasons, a directory needs to be watched for new files, file changes, etc. When a change occurs, a certain action should be taken, like copying the files elsewhere or send an email with to notify someone of the changes. There are a lot of such imaginable scenarios to think of. Read More