The most comprehensive documentation on FreeBSD is in the form of manual pages. Nearly every program on the system comes with a short reference manual explaining the basic operation and available arguments. These manuals can be viewed using man:
% man command
where command is the name of the command you wish to learn about. For example, to learn more about ls, type:
% man ls
The online manual is divided into numbered sections:
User commands.
System calls and error numbers.
Functions in the C libraries.
Device drivers.
File formats.
Games and other diversions.
Miscellaneous information.
System maintenance and operation commands.
Kernel developers.
In some cases, the same topic may appear in more than one section of the online
manual. For example, there is a chmod user command and a
chmod() system call. To tell man which section to display, specify the section number:
% man 1 chmod
This will display the manual page for the user command chmod. References to a particular section of the online 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.
If you do not know the command name, use man -k to search for keywords in the command descriptions:
% man -k mail
This command displays a list of commands that have the keyword “mail” in their descriptions. This is equivalent to using apropos(1).
To determine what the commands in /usr/bin do, type:
% cd /usr/bin % man -f *
or
% cd /usr/bin % whatis *
FreeBSD includes many applications and utilities produced by the Free Software Foundation (FSF). In addition to manual pages, these programs may include hypertext documents called info files. These can be viewed using info or, if editors/emacs is installed, the info mode of emacs.
To use info(1), type:
% info
For a brief introduction, type h. For a quick command reference, type ?.