Description

   If sv is not NULL, it specifies the address of a structure
   containing a pointer to a handler routine and mask to be used
   when delivering the specified signal, and a flag indicating
   whether the signal is to be processed on an alternative stack.
   If sv->onstack has a value of 1, the system delivers the signal
   to the process on a signal stack specified with sigstack.

   The sigvec function establishes a handler that remains
   established until explicitly removed or until the image
   terminates.

   The sigvec structure is defined in the <signal.h> header file:

   struct sigvec
      {
         int   (*handler)();
         int   mask;
         int   onstack;
      };

   See the "Error and Signal Handling" chapter of the VSI C RTL
   Reference Manual for more information on signal handling.