Woah... hold your horses, we need to cover some basics about commands. A command is a process run by a POSIX (Portable Operating System Interface) compliant OS (Operating System). OpenGroup maintains the standard in addition to it being ratified as an IEEE standard (http://pubs.opengroup.org/onlinepubs/9699919799/). In a POSIX environment, the process being run will have an environment, a current working directory, the command line (the path name that invoked the command and any arguments), and a series of file descriptors with stdin, stdout, and stderr (referred to by integer numbers 0, 1, and 2, respectively) being connected prior to handoff to your command.
Now with a little background and an installed command line, ...
