The man pages (short for manual pages) GNU Info The help command and –help option Other documentation sources, e.g. Gentoo Handbook or Ubuntu Documentation.
man pages
- The
man
program is in charge of searching and showing documentation. - A given topic may have multiple pages associated with it and there is a default order determining which one is displayed when no options or section number is specified (in
/etc/man_db.conf
) - The man pages are divided into chapters numbered 1 through 9
man command #Shows the manual entry for the command
man -f command #Lists all entries (can be more than one) for the command
whatis command #Same as above
man -k command #List all entries where the command is mentioned (can be from other commands)
apropos command #Same as above
man -a command #display all "command" pages in all chapters, one after the other
GNU Info
- Similar to
man
but works with subsections and links - Accessible through
info
tool.
To navigate: Action | Key —|— Move | Arrows Next Page | Page Up
Previous Page | Page Down
Select menu item | Enter
Quit | q
Help | h
Go to next | n
Go to previous | p
Move one node up in the index | u
--help
and help
--help
:Most commands provide a short way to get some reference passing the--help
flag.help
Is a program that can be used inside bash shells to get help about commands that run especially built-in bash versions. A list of these commands is shown usinghelp
Other sources
Include:
- Desktop help system: All Linux desktop systems have a graphical help application. This contains desktop specific help as well as some rendered
man
andinfo
pages. Can be runned from GUI or CLI (For example, for GNOMEgnome-help
oryelp
) - Package documentation: Linux documentation is also available as part of the package management system. Usually, this documentation is directly pulled from the upstream source code, but it can also contain information about how the distribution packaged and set up the software. Normally available in
/usr/share/doc
- Online resources: Include forums, and doc pages. Also ebooks, like this one