Below is the list of available man sections. Every section has a unique number and contains only a specific type of man pages.
- 1 – Executable programs or commands
- 2 – System calls ( functions provided by the kernel )
- 3 – Library calls ( functions provided by the library )
- 4 – Special files
- 5 – File formats and conventions ( configuration files )
- 6 – Games
- 7 – Miscellaneous
- 8 – System administration commands
$ man <topicname>
View the Man Page of a commandTo read the man page of an Linux command, pass the command name as the argument to the man. The following will display the man page for passwd command.
$ man passwd
PASSWD(1) User utilities PASSWD(1)
passwd - change user password
Some topics may even have man pages in more than one section. In such a case, man command will display the page which has lower section number.
In this example, the passwd command has manual pages in multiple sections. But, by default, it displays the man page from the section 1.
The “PASSWD(1)” shown in the 1st line of the man command output indicates that it is displaying the man page from section 1. The man page output displays the command name, syntax of the commands, description of what the command does, options provided by the command, etc…
View Man Page from a Specific SectionTo read the man page from a particular section, provide the section number as follows. The passwd command has man page in both section 1 and section 5. By default, if you don’t specify the section number, it will display man page from section 1.
To display man page from section 5, specify the section number as shown below.
$ man 5 passwd
Now it will display the manual page for /etc/passwd configuration file, since the section number 5 is for File Formats and Conversions.
List Available Man Sections for a CommandYou can also list all the available sections on a particular topic using -aw option.
$ man -aw printf
View All Man Pages for a Command – Display All SectionsTo view all the man pages for a particular topic, use the “-a” option. You’ll see the lowest-number man page first. When you exit that page, and press “Enter” the next man page will appear.
$ man -a printf
Change the Default Pager used by Man Command
By default man command will use the $PAGER environment variable to identify which pager to use for showing output. User can change the pager in which they prefer to see the man page using ‘-P’ option.
The following command will display the man page using more command pager.
$ man -P more printf
Search Man Page against NAME SectionTo search the man page against NAME section, use “-f” option as shown below.
$ man -f printf
printf (3) - formatted output conversion
This is equivalent to using whatis shell command.
The above command, searches the manual page names, and displays the description for the given topic if the manual page names, matches with the given topic. You can also pass multiple topics in the same command line.
Search Man Page against NAME and DESCRIPTION SectionTo search the man page against NAME & DESCRIPTION section, use “-k” option. It is equivalent to using “apropos” shell command.
$ man -k printf
printf (1) - format and print data
printf [builtins] (1) - bash built-in commands, see bash(1)
printftest (6) - tests the vgagl gl_printf function
set_matchpathcon_printf [set_matchpathcon_flags] (3) - set flags controlling the operation of matchpathcon or matchpathcon_index and configure the behaviour of validity checking and error displaying
The above command will search for the keyword “printf” as regular expression and display the man pages that match the keyword.