Autotools install directory

[Bernard]

Hello,

Using autotools to build projects I would like to specify installation
directory in a more custom way.

For instance I'm working on both linux and SUN system and I would like
programs to be installed in /home/bernard/bin/linux and
/home/bernard/bin/sun depending of the platforms on which I'm compiling.

I thought of defining an environment variable like $system which would
contain 'linux' or 'sun' that I would somewhat use in configure.in or
makefile.am but I don't see how...

Could someone point me to the right direction ?

Thanks in advance,