SSIGNAL(3C)              DOMAIN/IX SYS5               SSIGNAL(3C)



NAME
     ssignal, gsignal, - software signals

USAGE
     #include <signal.h>

     int(*ssignal(sig, action))( )
     int sig, (*action)();

     int gsignal(sig)
     int sig;


DESCRIPTION
     Ssignal and gsignal implement a software facility similar to
     that provided by signal(2).  This facility, used by the
     Standard C Library, allows you to specify how to dispose of
     error conditions.

     Software signals available to you are associated with
     integers in the inclusive range 1 through 15. A call to
     ssignal associates a procedure, action, with the software
     signal sig.  The software signal, sig, is raised by a call
     to gsignal.  Raising a software signal causes the action
     established for that signal to be taken.

     The first argument to ssignal is a number identifying the
     type of signal for which an action is to be established.
     The second argument defines the action; it is either the
     name of a (user-defined) "action function" or one of the
     manifest constants SIG_DFL (default) or SIG_IGN (ignore).
     Ssignal returns the action previously established for that
     signal type; if no action has been established or the signal
     number is illegal, ssignal returns SIG_DFL.

     Gsignal raises the signal identified by its argument, sig,
     in the following cases.

     ⊕  If an action function has been established for sig, then
        that action is reset to SIG_DFL and the action function
        is entered with argument sig.  Gsignal returns the value
        returned to it by the action function.

     ⊕  If the action for sig is SIG_IGN, gsignal returns the
        value 1 and takes no other action.

        If the action for sig is SIG_DFL, gsignal returns the
        value zero and takes no other action.

     ⊕  If sig has an illegal value or no action was ever



Printed 12/4/86                                         SSIGNAL-1

SSIGNAL(3C)              DOMAIN/IX SYS5               SSIGNAL(3C)



        specified for sig, gsignal returns the value zero and
        takes no other action.

NOTES
     There are additional signals, with numbers outside the range
     1 through 15, that are used by the other library functions
     to indicate error conditions; these are defined in
     <signal.h>.  If you specify one of them as sig, your program
     may interfere with the normal operation of these functions.

RELATED INFORMATION
     signal(2)









































SSIGNAL-2                                         Printed 12/4/86