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 ...

Bash, aka the Bourne-Again Shell, has a newly discovered security hole. And, for many Unix or Linux Web servers, it's a major problem. The flaw involves how Bash evaluates environment variables. With ...

It is easy to dismiss bash — the typical Linux shell program — as just a command prompt that allows scripting. Bash, however, is a full-blown programming language. I wouldn’t presume to tell you that ...

If you're working in a Linux environment, chances are you've encountered environment variables—even if you didn’t realize it at the time. They quietly power much of what goes on behind the scenes in ...

I'm working on some scripts that execute on various servers, and I'm trying to consolidate them into one. The problem is that I need to run remote commands but can't ...

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 ...

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 ...