There are six different shells available, each with it's own program used to run it.

The earliest UNIX shell that is still in use is the Bourne shell. The Korn and Bash shells are similar to the Bourne shell, but have several important features which the Bourne shell lacks. These include a history function, job control and aliasing.

The final member of the Bourne Shell Family is Zsh. It is similar to the Bourne, Korn and Bash shells, but it also has more advanced options and has therefore become popular among programmers and advanced UNIX users.

The C-Shell Family includes the C-Shell itself, which was designed to be an alternative to the Bourne shell. The two shells are very similar, but the C-Shell offers many advantages which the Bourne shell doesn't. The C-Shell is the most popular shell in use at universities and in research and is the default shell on ROHAN.

The other member of the C-Shell family is Tcsh. It is similar to the C-Shell, but it offers enhanced features and is often the preferred shell among advanced users.

By default, accounts on ROHAN are setup using the C-Shell. However, it is very easy to change shells at any time by simply typing in the name of the shell you wish to use at the rohan% prompt. This change will only last during your current login session. Once you exit, the shell changes back to it's default setting. If you want to change your default shell, use the chsh command. The syntax is:

rohan% chsh  userid  name of new shell

When you use chsh to change your shell, the change will not take place until the next time you log in.