Up to this point, we have seen a series of mysterious commands, each with its own mysterious options and arguments. In this chapter, we will attempt to remove some of that mystery and even create some of our own commands. The commands introduced in this chapter are these:
type—Indicate how a command name is interpreted.
which—Display which executable program will be executed.
man—Display a command’s manual page.
apropos—Display a list of appropriate commands.
info—Display a command’s info entry.
whatis—Display a very brief description of a command.
alias—Create an alias for a command.
A command can be one of four things:
An executable program like all those files we saw in /usr/bin. Within this ...