Regex builder

We’ve covered several regular expression tools here on the site that make generating and testing your regex code easy, and today we’ve got a Windows app that does a bit more hand-holding. Expresso is a free (requires free registration) tool that has a built-in library of various expressions ready to be used, but also includes an Expression Builder for making your own.

As you can see in the screenshot above the Expression Builder has various tabs that let you do the assembling piece-by-piece. Just select the options and click the insert button to have it add the regex block to your existing statement. If you’re trying to pickup how regex works this is a great utility to show you the ropes. Plus the built-in tester lets you know if it’s working the way you want before you go and deploy it in your code.

Here’s a list of features highlighted by the developer:

  • Build complex regular expressions by selecting components from a palette
  • Test expressions against real or sample input data
  • Display all matches in a tree structure, showing captured groups, and all captures within a group
  • Build replacement strings and test the match and replace functionality
  • Highlight matched text in the input data
  • Test automatically for syntax errors
  • Generate Visual Basic, C#, or C++ code
  • Save and restore data in a project file
  • Maintain and expand a library of frequently used regular expressions
  • Full Undo/Redo capability
  • Export match results to Excel, XML, etc.

I still believe this is a pretty nice app despite the fact that you have to register (for free) to use it beyond the 60-day trial. The good news is that you can just use a one-time email address because all you need is the activation code that it will send off to you.

Expresso Homepage (Windows only; Freeware – requires free registration)