The Command Interpreter





                  The "shell" is the command interpreter
                  It is the most external layer of a Unix system

                           % \ls -1 /bin/*sh
                           /bin/bash
                           /bin/csh
                           /bin/dash
                           /bin/fdflush
                           /bin/ksh
                           /bin/pdksh
                           /bin/rbash
                           /bin/sash
                           /bin/sh
                           /bin/tcsh
                           /bin/zsh