Oh happy day! I got an e-mail from a reader with a shell script question that didn't appear to be homework from a programming class or anything to do with hacking passwords. The reader wrote: I am ...

Jack Wallen shows how you can create a Linux shell script that requires a password without having to save a password within the script. Linux is the most flexible ...

You normally think of a critical section — that is, a piece of a program that excludes other programs from using a resource — as a pretty advanced technique. You certainly don’t often think of them as ...