Ok, I answered my own question.

There are two possible interfaces that allow Unix binaries 
to run on Linux. The iBCS for Linux 2.2 kernels and the Linux ABI
for 2.4 kernels. There does seem to be some limitation and some
Unices require certain shared (proprietary) libraries to be available.
It looks as though UnixWare may be ok though.

Thanks for the pointers.

Brian

> -----Original Message-----
> From: Brian Densmore 
> Sent: Wednesday, December 17, 2003 2:26 PM
> To: KCLUG (E-mail)
> Subject: RE: Unix program on Linux question
> 
> 
> > -----Original Message-----
> > From: Duane Attaway
> > 
> > If I remember right, when the file is handed to the kernel, 
> > it looks for a
> > few magic bytes at the beginning of the file to determine if 
> > its a script,
> > who handles it, or what kind of binary it is.  Usually a 
> > strings command
> > on the file for the first line will tell the tale.  Also, 
> > this is a crude
> > way to find out what libraries and functions are called.
> Ok. That makes sense, but, does that mean Linux can run Unix
> compiled code or not? 
> 
> 
> 
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