sigvec(3)                                                     sigvec(3)

  sigvec()

  NAME

    sigvec() - BSD software signal facility

  SYNOPSIS

    #include 
    struct sigvec {
        void   (*sa_handler)();
         int sa_mask;
         int   sa_flags;
    };

    int sigvec (int signum, struct sigvec *vec, struct sigvec *ovec)

  DESCRIPTION

    This interface is made obsolete by sigaction(2). See the sigaction(2)
    reference page for a description of signals and signal handling and a list
    of signals.

    The sigvec(3) function assigns a handler for a specific signal. If vec is
    non-zero, it specifies a handler routine and mask to be used when
    delivering the specified signal. If ovec is non-zero, the routine returns
    the previous handling information for the signal.

    Once a signal handler is installed, it remains installed until another
    sigvec(3) call is made, or until an exec(2) is performed. A signal-
    specific default action may be reset by setting sa_handler to SIG_DFL. The
    defaults are process termination; no action; stopping the process; or
    continuing the process. See the list in sigaction(2) for each signal's
    default action. If sa_handler is SIG_IGN, current and pending instances of
    the signal are ignored and discarded.

    After a fork(2) all signals, the signal mask, the signal stack, and the
    restart/interrupt flags are inherited by the child.

    The exec(2) family of routines reinstates the default action for all
    isgnals which were caught, and resets all signals to be caught on the user
    stack. Ignored signals remain ignored; the signal mask remains the same;
    signals that interrupt system calls continue to do so.

  RETURN VALUES

    A 0 value indicated that the call succeeded. A -1 return value indicates
    an error occurred and errno is set to indicated the reason.

  ERRORS

    The sigvec(3) function will fail and no new signal handler will be
    installed if one of the following occurs:

    [EFAULT]
        Either vec or ovec points to memory that is not a valid part of the
        process address space.

    [EINVAL]
        Signum is not a valid signal number.

    [EINVAL]
        An attempt is made to ignore or supply a handler for SIGKILL or
        SIGSTOP.

  NOTES

    The mask cannot block SIGKILL or SIGSTOP. This is enforced silently by the
    system.

    This implementation does not suport such flags as SV_INTERRUPT or
    SV_ONSTACK. The only flag available to sa_flags is SA_NOCLDSTOP. See
    sigaction(2).

  SEE ALSO

    kill(1)

    kill(2)

    setjmp(3)

    sigaction(2)

    sigblock(3)

    signal(2)

    sigprocmask(2)

    sigsetmask(3)

    sigsuspend(2)

  USAGE NOTES

    The sigvec function is thread safe.

    The sigvec function is not async-signal safe.