If you consider yourself a good cook, you may or may not know how to make a souffle or baklava. But there are certain things you probably do know how to do that form the basis of many recipes. For ...

These are the formal rules for forming basic UNIX regular expressions. For some simple examples, skip to Simple Examples. The rules come from the Solaris 7 regexp(5) manual page. The I2A2 reflector ...

Imagine you are looking for a name in a telephone directory, but you can't remember its exact spelling. You can spend ages searching through all the possible combinations, unless you have a tool that ...

Regular expressions — the things you feed to programs like grep — are a bit like riding a bike. It seems impossible until you learn to do it, and then it’s easy. Part of their bad reputation is ...

When working with regular expressions in a shell script the norm is to use grep or sed or some other external command/program. Since version 3 of bash (released in 2004) there is another option: ...

Regular expressions are a way to describe patterns of text that can be useful for processing text documents or wherever one might want to look for a pattern and possibly replace another. Imagine you ...