Creating more readable regular expressions with Simple Regex Language

Clear-Sighted

Article from Issue 199/2017
Author(s):

Regular expressions are a powerful tool, but they can also be very hard to digest. The Simple Regex Language lets you write regular expressions in natural language.

Regular expressions are a fundamental feature of Linux – and many other modern operating systems. A regular expression is a search term with special placeholders representing several possible characters at the same time. The concept of a regular expression is an extension of the idea behind the "wildcard" character used in many GUI search tools, but the power and subtlety of regular expressions far exceeds what you can do with a simple wildcard.

For example, suppose you want to search the system.log file for errors, but you don't know whether the term Error will appear with initial cap or all lowercase (Error or error). You could use a regular expression as part of the Grep command:

grep -e '[eE]rror' system.log

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