A Brief Introduction to the Use of Shell Variables (2001)

by Norman Matloff.

There are many different shells available for Unix systems. Here we focus on two of the most popular ones, tcsh and bash. Other shells tend to be very similar to one or both of these. Your Unix account has a preset login shell for you, typically tcsh in academic settings and bash in Linux. When you log in, a shell of the given type is automatically started for you. (This can be seen in the file /etc/passwd.) If you wish to temporarily run a different shell, just type its name. If you wish to change your login shell, run the chsh command. [via]

http://heather.cs.ucdavis.edu/~matloff/UnixAn...