set42sig(3)                                           set42sig(3)



NAME
     set42sig - sets the Berkeley Software Distribution (BSD) 4.2
     signal interface

SYNOPSIS
     int set42sig()

DESCRIPTION
     set42sig changes the signal interface to one closely
     resembling BSD 4.2 systems.  This call is similar to the
     setcompat system call. Unlike setcompat(2), set42sig
     arranges for the current compatibility flags to be logically
     OR'ed with the new flags.  set42sig is functionally
     equivalent to the following C code fragment:

        #include <compat.h>

        return (setcompat(getcompat() | COMPAT_BSDSIGNALS |
                COMPAT_BSDTTY | COMPAT_SYSCALLS));

     For the process calling it, set42sig enables reliable signal
     delivery, the job-control tty signals, and restarting of
     system calls when an interrupt is received.

     If you set the COMPAT_SVID flag before calling set42sig,
     both BSD 4.2 and System V modes are set and BSD 4.2 mode
     will have precedence.  You can set COMPAT_SVID in two ways:
     by calling setcompat(2) and by compiling the program with
     the -ZS option (see cc(1)).

     All aspects of BSD 4.2 signals are inherited across fork
     system calls. BSD 4.2 job-control group membership is
     inherited across exec system calls.  When exec is invoked,
     the inherited BSD 4.2 signals are lost and the signal-
     handling mechanism returns to System V style.  See
     setcompat(2) for more information.

STATUS MESSAGES AND VALUES
     EINVAL
          The process has already arranged to catch signals.
          Normally set42sig is called prior to any other signal
          activity.

SEE ALSO
     setcompat(2), sigvec(2), signal(3), termio(7)

     cc(1) in A/UX Command Reference








January 1992                                                    1