It makes it much easier than typing environment variables everytime.

This is a simple question that will probably be easy for you to answer. I know I could Google a code snippet to do what I need to do. I hope that, more than giving me the right code, you can explain ...

Have you ever wanted to force a script to act differently when it is invoked by cron? If the script is run interactively, for example, you might want the script to prompt the user for some information ...