Linux: How to find man page or different versions of Linux commands? [closed]

Question

I'm not sure what it's called exactly. But offen in a Linux 'man' page it refers to the same command but a different "version" number. For example:

$ man signal

Is SIGNAL(2), but there refers to a SIGNAL(5), for example. I tried this but it doesn't work on Linux CentOS 6:

$ man 5 signal
No entry for signal in section 5 of the manual

How do I find/access the man page for SIGNAL(5)? Thanks!

Answer 1

You are using it correctly in Linux. To get in what section a command exists, use whatis.

$ whatis printf
printf               (1)  - format and print data
printf               (3)  - formatted output conversion

The syntax for accessing the non-default manual section varies between different man implementations. On Solaris, for example, the syntax for reading printf(3) is:

man -s 3c printf

On Linux and BSD derivatives the same invocation would be:

man 3 printf

which searches for printf in section 3 of the man pages.

Answer 2

If you don't care about the numbers you can just run man -a signal and it will show you all signal manpages it knows about.