Calling the raise function has one of the following results:

    o  If raise specifies a sig argument that is outside the range
       defined in the <signal.h> header file, then the raise function
       returns 0, and the errno variable is set to EINVAL.

    o  If signal, ssignal, or sigvec establishes SIG_DFL (default
       action) for the signal, then the functions do not return. The
       image is exited with the OpenVMS error code corresponding to
       the signal.

    o  If signal, ssignal, or sigvec establishes SIG_IGN (ignore
       signal) as the action for the signal, then raise returns its
       argument, sig.

    o  signal, ssignal, or sigvec must establish an action function
       for the signal. That function is called and its return value
       is returned by raise.

    See also gsignal, signal, ssignal, and sigvec.