Search code examples
csystem-callsmanpage

what is the meaning of 3 in strftime(3),malloc(3) etc

This might be a silly question. but I was wandering a long time searching for this .but couldn't solve. For some functions I've seen (8) also. They are mostly seen on documentations. Could anyone please help.

Solution

  • The man pages are divided into sections with different topics:

    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

    man 2 open will look for open in system calls and tell you details about the Linux system call, while man 3 open will look for open in C Library Functions and tell you about the ANSI or POSIX specification of open.

    See the difference here for example:
    http://linux.die.net/man/2/open
    http://linux.die.net/man/3/open