Using Other Shells
Essentially, all the shells
on the system (sh, bash, ksh, tcsh, and zsh) do the same thing: they take input from you and translate it into commands that are run on the system. However, each shell differs in the specifics of how you interact with it and the special features that it offers. If you’ve never used the Unix shell, you’ll do just fine sticking with the default bash shell. But if you’ve become accustomed to the tcsh shell that was the default on earlier versions of Mac OS X, or if you are an old-hand Unix user who simply prefers another shell, you may want to change the default shell to suit your preferences.
Because a shell is a program like any other, all you have to do to use a different shell temporarily is type its name at the command line. For example, if you want to use the tcsh shell, execute the following:
$ tcshThe prompt changes to a percent sign (%), which is the default prompt for the tcsh shell, and will be in effect until you exit out of it.