Nagios
 

I am installing Nagios in RHEL 6.5. While going through the steps, I found following command

./configure --with-command-group=nagcmd

What whole command does?

What is ./ And what it basically does?

Thank you in advance.

./ is your current directory.

The configure script is a shell script that checks out if you have the necessary prerequisites to compile the software and configures it correctly for your system. It is part of the GNU autoconf/automake suite; refer to the documentation of autoconf and automake for further details.

In general, you probably should be installing software from your distro's package manager, if possible.