Dr. Drang had a nice little post on getting started with regular expressions. If you’re anything like me and have been a little leery of these when looking at Shortcuts this is worth a read.
If you’re writing a regex for any platform having a debugging tool
is very helpful. I use a commercial tool that runs on Windows only, so I won’t post that here. However, there are several online tools that work just fine. This is just one of hundreds, so look for one that suits you best.
This older topic may be worth a look too if people are interested in tooling options.