RE: Call to execvp in Rational Ada

["Steven Deller" <a101.deller@smsail.com>]

Peter,
The results you are seeing are consistent with the UNIX execvp
interface.

You seem to have a mistaken expectation of the call to the UNIX execvp
operation.  Both exec and execvp are UNIX functions that will never
return from a correct call -- in UNIX "exec" replaces your running
process with the new process specified.  The status is ONLY there in
case the arguments are bogus.  

You may have meant to do a "fork and exec", but that has its own control
issues and is not for the uninitiated.

I suggest you look at the POSIX Ada (1003.5) calls for executing another
process -- the descriptions are quite clear and the interface from Ada
allows for safe operations.

The Rational "execvp" is a direct interface to the UNIX system.  It is
intended for use ONLY by people that fully understand OS issues such as
threads, exception handling, etc, and, in my opinion, has no business
being in application code.  The POSIX interface IS intended for
application code, and is reasonably portable among the various Ada
compiler vendors.

Regards,
Steven Deller

> Peter Richtmyer wrote:
> > I want to use Rational's "execvp". The following
> > is my test code. test results are listed at the end. Anybody know 
> > what I am doing wrong? Or have an example of doing it right that I