man

man is the system’s manual pager.

Section Numbers Of The Manual
1
2
3
4
5
6
7
8
9
1 Executable programs or shell commands
2 System calls (functions provided by the kernel)
3 Library calls (functions within program libraries)
4 Special files (usually found in /dev)
5 File formats and conventions eg /etc/passwd
6 Games
7 Miscellaneous (including macro packages and conventions)
8 System administration commands (usually only for root)
9 Kernel routines [Non standard]
man
man
man
man ls
Displays the manual page for ls.
man man.7
Displays the manual page for macro page man from section 7.
man -a intro
Displays in succession, all of the available intro man pages.
man -k printf
Search the short descriptions and manual page names for the keyword printf and print any matches.
man -f smail
Lookup the manual pages references by smail and print out the short descriptions of any found.