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
where command is the name of the command
you wish to learn about. For example, to learn more about
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
which will display the manual page for the user command
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
With this command you will be presented with a list of
commands that have the keyword `mail' in their
descriptions. This is actually functionally equivalent to
using the 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 *
or
% cd /usr/bin; whatis *
which does the same thing.