[NTLUG:Discuss] OT C system call question

[Chris Cox]

Fred James wrote:
> All
> In C there is "system"
> (SYNOPSIS
>     #include <stdlib.h>
> 
>     int system (const char *string);
> )
> 
> What I think I have found is that if the command inside the ( ... ) is a
> shell script and it returns a numeric value (as in: exit $i), the C
> program will see it as that number multiplied by 256 (i.e., 0 is 0, 1
> becomes 256, 2 becomes 512, etc.).  [these test were run on an SGI IRIX
> 6.4 machine]
> 
> Can anyone confirm or deny that, or offer any enlightenment, please? 
> Thank you in advance for any help you may be able to offer.

The return code is shifted 8 bits (so shift >>8).  ... but that's the same as
divide by 256.