man page

topics: Linux

source: What do the numbers in a man page mean? - Unix & Linux Stack Exchange
context: I was watching lecture from http://pwn.college for Linux Process and noticed the lecturer using man with numbers. I have seen it for a few times, but didn't really look into the difference.

Man page seem to have different sections.

MANUAL SECTIONS
    The standard sections of the manual include:

    1      User Commands
    2      System Calls
    3      C Library Functions
    4      Devices and Special Files
    5      File Formats and Conventions
    6      Games et. al.
    7      Miscellanea
    8      System Administration tools and Daemons

    Distributions customize the manual section to their specifics,
    which often include additional sections.

$ man 1 printf
$ man 3 printf
$ man -a printf

man 1 printf shows the printf command usage, while man 3 printf shows the printf C function signature.
man -a will show everything about the command.