The Unix shell reads a number of configuration files when it starts up. These configuration files are really shell programs, so they are extraordinarily powerful. Shell programming is beyond the scope of this book.
But let's look at what you can customize without having to become a full-fledged Unix geek, shall we?
The default login shell for Tiger is the ever-popular bash shell, but many Unix fans prefer to use the Korn shell (ksh) instead. As mentioned earlier, Mac OS X offers a host of different shells, including /bin/bash, /bin/csh, /bin/ksh, /bin/tcsh, /bin/zsh, and /bin/sh.
To change your login shell, you can either use the Unix chsh command (enter chsh on the command line and you'll be asked which shell you'd like starting the next time you log in), or just change it within the Terminal Inspector's Shell pop-up screen, as shown earlier, in Figure 2-3.