Using man command to get Linux online help, manual and documentation.

   Every Linux distributions usually include the help files or online documentation on their distribution.

Usually all the programs, commands, file format and library function installed on your hard drive have their own documentations.

   This documentations called man page or manual pages. Manual pages usually located under the /usr/man directory. These manual pages usually separated in several sections organized by task or type.

Need help using Linux command?

This article is provides information on how you can access this documentation or same say the online help by using the man command on the shell command line.

Getting Linux online help with man command

   The man command is used to access and print online help and documentation that you have on your Linux hard drive.  To read the manual page for program or command, use the man command and specify the name of command or program that you want to read the manual.

man command syntax:

[root@fedora ~]# man program_name

Example on using man command to read the manual entry:

The example below use the man command to read the manual entry for the command man itself

[root@fedora ~]# man man

   To read the manual on the other manual pages section, use the man command with the section option.

man command syntax to look on the documentation on different section:

man section_number program_name

For example:

[root@fedora ~]# man 7 man

To exit the manual page viewer press q on your keyboard key.

These on line help or manual usually have the information on:

1. the description on what the the command does.

2. The list of options or syntax that the command can accept.

3. Other information related for the command and usually at the end of the manual page, you can find the name of the author.

To find out which section number that you want to find the documentation that you looking for use the apropos command.

apropos command syntax:

[root@fedora ~]# apropos string

or you can use man command with the -k option:

[root@fedora ~]# man -k string

To search for keyword string on all manual pages, use the quotes if there is any spaces between the keyword:

[root@fedora ~]# man -K string_example

[root@fedora ~]# man -K "this is string example"

This method is searching the keyword on all the documentation that available on your system, this procedure can take some time to finish.  Not recommended if you are on hurry.

To list the details associated with the command, use man command with  [ -f  ] option:

command syntax:

[root@fedora ~]# man -f command_name

Command execution example:

[root@fedora ~]# man -f mount

To display a one line description on what command does, you can use the whatis command:

command syntax:

[root@fedora ~]# whatis command_name

Command execution example:

[root@fedora ~]# whatis mount

Note:  The man -f, whatis and apropos command relies on whatis database; as an root user, you need to run the makewhatis command to rebuild or update whatis database.

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