Using the Linux man pages

You must have noticed the convention followed in most Linux/Unix literature:

• The suffixing of user commands with (1) – for example, gcc(1) or gcc.1
• System calls with (2) – for example, fork(2) or fork().2
• Library APIs with (3) – for example, pthread_create(3) or pthread_create().3

As you are no doubt aware, the number in parentheses (or after the period) denotes the section of the manual (the man pages) that the command/API in question belongs to. A quick check with man(1), via the man man command (that's why we love Unix/Linux!) reveals the sections of the Unix/Linux manual:

$ man man
[...]
A section, if provided, will direct man to look only in that section of
the manual. [...]

       The table below shows the section numbers of the manual followed by the types of pages they contain.

       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), e.g. 
           man(7), groff(7)
       8   System administration commands (usually only for root)
       9   Kernel routines [Non standard]
[...]

So, for example, to look up the man page on the stat(2) system call, you would use the following:

man 2 stat # (or: man stat.2)

At times (quite often, in fact), the man pages are simply too detailed to warrant reading through when a quick answer is all that's required. Enter the tldr project – read on!