Help Commands in Linux

any_command −−help |more
Display a brief help on a command (works with most commands). For example, try cp −−help |more. "−−help" works similar to
DOS "/h" switch. The "more" pipe is needed when the output is longer than one screen.

man topic
Display the contents of the system manual pages (help) on the topic. Press "q" to quit the viewer. Try man man if you need any
advanced options. The command info topic works similar to man topic, yet it may contain more up−to−date information.
Manual pages can be hard to read−−they were written for UNIX programmers. Try any_command −−help for a brief, easier todigest help on a command. Some programs also come with README or other info files−−have a look to the directory
/usr/share/doc. To display manual page from a specific section, I may use something like: man 3 exit (this displays an info
on the command exit from section 3 of the manual pages) or man −a exit (this displays man pages for exit from all sections).
The man sections are: Section 1−User Commands, Section 2−System Calls, Section 3−Subroutines, Section 4−Devices, Section
5−File Formats, Section 6−Games, Section 7−Miscellaneous, Section 8−System Administration, Section 9, Section n−New. To print a
manual page, I use: man topic | col −b | lpr (the option col −b removes any backspace or other characters that could
make the printed manpage difficult to read).

info topic
Display the contents of the info on a particular command. info is a replacement for man pages so it contains the most recent updates
to the system documentation. Use and to move around or you may get confused. Press "q" to quit. A
replacement for the somewhat confusing info browsing system might be pinfo − try if you like it any better.

apropos topic
Give me the list of the commands that have something to do with my topic.

whatis topic
Give me a short list of commands matching my topic. whatis is similar to apropos (see the command above)−−they both use the
same database. But whatis searches keywords, while apropos also searches the descriptions of the keywords.

help command
Display brief info on a bash (shell) built−in command. Using help with no command prints the list of all bash built−in commands.
The shortest list of bash built−in commands would probably include: alias, bg, cd, echo, exit, export, fg,
help, history, jobs, kill, logout, pwd, set, source, ulimit, umask, unalias, unset.

kdehelp
kdehelpcenter
(in X−terminal, two commands, use the one that works on your system). Browse the whole system help using the graphical KDE help
navigator. Normally, KDE help is invoked by pressing the appropriate icon on the KDE control panel. Use gnome−help−browser for the GNOME equivalent.