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 ...

One of the common tasks you'll encounter when scripting in Bash is performing arithmetic operations on variables, particularly division. This process might seem straightforward, but it requires ...

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 ...

Are you currently learning Bash? Have you seen things like $0 and $EUID and wondered what they mean? Or what the difference is between $UID and $EUID? I'll cover ...

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 ...

In our first tutorial on command line wizardry, we covered simple redirection and the basics of sed, awk, and grep. Today, we’re going to introduce the concepts of simple variable substitution and ...

Simply put, environment variables are variables that are set up in your shell when you log in. They are called “environment variables” because most of them affect the way your Unix shell works for you ...

Bash vs. Fish? I've tried both Linux shells, and one makes using the command line much easier ...