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 ...

Check if a file is really a file, whether a string contains anything, and whether you can run a program with these vital patterns.

Here are some basic skills to get started with bash, one of the best shells for preparing and using scripts on Linux. Scripting in Linux–putting commands into a file so you can run them as a group—is ...

We often read (including in the book Advanced Bash-Scripting Guide by Mendel Cooper) that if we pass variable names as parameters to functions, they will be treated as string literals and cannot be ...

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 ...

A software vendor has given us a script that sets some environmental variables. It needs to be run manually by cd-ing into the directory and executing '. ./.script.sh'. This seems a bit weird to me - ...

Finally, I'm going to finish the mail merge script, just in time for Replicant Day. Oh, sorry, back to topic here. I was developing a shell script that would let you specify a text document with ...