Linux Shell Scripting Cookbook - Third Edition

How it works...

The script checks whether the script is running for the first time using [ ! -e "last.html" ];. If last.html doesn't exist, it means that it is the first time, and the web page must be downloaded and saved as last.html.

If it is not the first time, it downloads the new copy (recent.html) and checks the difference with the diff utility. Any changes will be displayed as diff output. Finally, recent.html is copied to last.html.

Note that changing the website you are checking will generate a huge diff file the first time you examine it. If you need to track multiple pages, you can create a folder for each website you intend to watch.