Problem with getuid() -- same as geteuid()?!

[Steven Winikoff]

I've encountered a problem using getuid(), on both a Sun 4/280 under
SunOS 4.0 and a MIPS M-120/5 under MIPS RISC/os 4.0.1 (SVR3 plus BSD
compatibility).  The following short program produces the same results 
on both systems, and replicates the behaviour I've experienced in the 
middle of a much larger application:

#include <stdio.h>
main()
{
   int getuid();
   printf("uid = %d\n", getuid());
}

When I log in as user "smw" (user index = 1000), the program does indeed
return "uid = 1000".

However, when I then execute the su command, I receive "uid = 0" instead
of the expected "uid = 1000".  

Am I missing something?  I thought that this was the expected behaviour
for geteuid() instead of getuid(), and that's why I used getuid() in the
first place!

Can anyone tell me if I'm just confused, or if I'm simply not doing it
right, or if there's actually a bug in the Sun and MIPS implementation 
of these calls?

Thanks very much in advance!

	Regards,

	   - Steven

------------------------------------------------------------------------
Steven Winikoff                                 smw at maxwell.concordia.ca
Software Analyst
Dept. of Computing services
Concordia University                            voice: (514) 848-7619
Montreal, Quebec, Canada                               (10:00-18:00 EST)