The most comprehensive documentation on FreeBSD is in
the form of man pages. Nearly every program
on the system comes with a short reference manual
explaining the basic operation and various arguments.
These manuals can be view with the
man command. Use of the
man command is simple:
man command
ls command type:
% man ls
The online manual is divided up into numbered sections:
chmod user command and a
chmod() system call. In this case,
you can tell the man command which
one you want by specifying the section:
% man 1 chmod
chmod. References to a particular
section of the on-line manual are traditionally placed
in parenthesis in written documentation, so
chmod(1) refers to the chmod user command and chmod(2)
refers to the system call.
This is fine if you know the name of the command and
simply wish to know how to use it, but what if you cannot recall the
command name? You can use man to
search for keywords in the command descriptions by
using the -k switch:
% man -k mail
apropos command.
So, you are looking at all those fancy commands in /usr/bin but do not even have the faintest idea
what most of them actually do? Simply do a
% cd /usr/bin; man -f *
% cd /usr/bin; whatis *