[Info-vax] Looking into C-include files on VMS

[glen herrmannsfeldt]

Bob Koehler <koehler at eisner.nospam.encompasserve.org> wrote:
> In article <7krs6vF3af5v3U10 at mid.individual.net>, Bob Eager <rde42 at spamcop.net> writes:
 
>> You miss the point. They are talking about VMS SPAWN, which is unlike 
>> vfork()+exec(). It is nearer to creating a new (empty) process and 
>> loading a program into it.
 
>   Doesn't that end up with the same thing?  I would expect vfork() to
>   start a new process and exec() to load a new program into it.

Note that vfork() and fork() are different.  On my system:

  "Vfork() can be used to create new processes without fully copying the
   address space of the old process, which is horrendously inefficient in a
   paged environment.  It is useful when the purpose of fork(2) would have
   been to create a new system context for an execve(2).  Vfork() differs
   from fork(2) in that the child borrows the parent's memory and thread of
   control until a call to execve(2) or an exit (either by a call to _ex-
   it(2) or abnormally).  The parent process is suspended while the child
   is using its resources."

-- glen