Jack Wallen introduces you to Linux environment variables. What are they and how are they set and unset? How many times have you installed something on Linux, only to find out that you need to set ...

Variables often look like $var, but they also look like $1, $*, $? and $$. Let's take a look at what all these $ values can tell you. A lot of important values are ...

Editor's Note: This article has been updated by its author. Thank you, Pat. Have you ever wanted to change the names of many files at once? Or, have you ever needed to use a default value for a ...

This post follows up on Part 1 by examining the many ways that you can test the value of variables – e.g., whether they equal particular strings like “yes” or “no”, if they have a numeric value, if ...