Newbie question - testing for OS. . .

[bC]

Hello,

  I'm a new subscriber, but not at all new to computers, but VERY new to
make file writing, but not at all new to programming.

  I've built a couple simplistic make files to install my program, needed
data files and libraries.... one aimed at being used on Fedora Core 3, the
other on Fedora Core 5.  Those are currently the two favorites of my target
audience; and I've found them to vary in what libraries are present by
default.

  I'd like to maintain just the one make file... so, I need a test and
decision based upon which version of the OS the make utility finds itself
running under.  I would appreciate a kick-start in the right direction.
Thanks in advance!

  In the long run, I'd like to evolve things to take care of the
possibility of the make utility running under other Fedora variants and
ultimately other Linux variants, so any hints there would be appreciated as
well.

Thank you again.

-bC