Whether you're a developer, systems administrator, network specialist, or QA analyst, you have probably found yourself parsing some kind of log file looking for patterned information. Regular expressions can be a very powerful method for getting to the exact information you are looking for in those logs. And applications such as Windows PowerShell are very handy tools to rely on. But, with their sometimes seemingly esoteric and perhaps lengthy structures, these tools can make it extremely difficult to construct the expressions as you need them. If this sounds familiar, consider giving Expresso from Ultrapico a try. This tool makes it much easier to develop, test, and reuse regular expression.

Expresso's main UI provides three basic views for development: Test mode, Design mode, and the Expression Library view. In Test mode, there are four panes of functionality. The Regular Expression pane is where you actually edit the expression to find and/or replace the data you are looking for. The Sample Text pane shows the text that the regular expression will run on and to which you can paste in an appropriate sample. The Regex Analyzer pane gives you a very cool hierarchical tree view of your regular expression components, helping you see how each component of the expression will operate. And the Results pane, as you might expect, shows the results of the operations you perform.

Within Test mode, there are six operations you can perform with your expression to get those results: full match, partial match, match exclusion, replacement, validation, and split. Full match takes your regular expression and runs it against the sample text, while partial and exclusion matches take the part of the expression you highlight and match it with or exclude it from to ensure the inner parts of your expressions are working properly. And you can use the tree view to navigate and highlight a particular section automatically. Replacement and split do just as the names imply. And validation uses icons to indicate which lines in your sample text will match.

Design mode provides the Regex Analyzer and Regular Expression panes as well as a place for your replacement text (you will likely be flipping back and forth between the Test and Design modes as you work). Also, you get a great designer toolbox, which helps you build up complex expressions with simple GUI actions. You can insert blocks that work with characters, groups, position, repetitions, and substitutions; and find helpers for ASCII and Unicode character and control codes.

The Expression Library gives you a history of your project's expressions. The application is project based, so you can save your works in progress or frequently used workspaces and come back to them when you need to. A number of sample projects also come with the application to help you get started with regular expressions, such as a built-in overall Regular Expression Library function. The default library comes loaded with expressions you can tailor to your own needs. You can add (and delete) expressions or create your own libraries.

If you find yourself using the same few expressions repeatedly, just move them to the top of the order. Double-clicking an expression in the library dumps it back into the main application window so you can immediately apply it in your workspace.

Expresso also has built-in code generation functionality. This will create a C#, C++, or Visual Basic code wrapper for your designed expression set. And, if you want, it will even compile this into a ready-to-go DLL for use in your applications or Windows PowerShell scripts.

Whether you are just starting out with regular expressions, have been learning over time, or are a certified guru looking for a way to test and save your creations, check out Expresso. This free utility could become one of your most valuable tools.

Price: Free.