64 bit OS environment variable

[Nigel Wade]

Borg, Rodney wrote:
> Hi,
> 
> Does anyone know if there is an environment variable that would let a
> "make" script choose the correct 32 or 64 bit libraries to link?
> The particular application uses a Jam make.
> 


What are you trying to do?

If you have a 64bit platform the default compilation/linking will link 
to 64bit libraries. If you specify the -m32 compiler option (and use the 
compiler to generate the link commands) then a 32bit application will be 
built using 32bit libraries. A 32bit platform will use 32bit libraries, 
and can't build 64bit apps.

There is a variable (not environment) called MACHTYPE which you should 
be able to use to differentiate between a 32bit and 64bit environment, 
or the output of the command "arch".

-- 
Nigel Wade, System Administrator, Space Plasma Physics Group,
             University of Leicester, Leicester, LE1 7RH, UK
E-mail :    nmw at ion.le.ac.uk
Phone :     +44 (0)116 2523548, Fax : +44 (0)116 2523555