ssignal(3C)                                           ssignal(3C)



NAME
     ssignal, gsignal - produce software signals

SYNOPSIS
     #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
     signal(3).  This facility is used by the Standard C Library
     to enable users to indicate the disposition of error
     conditions; it is also made available to users for their own
     purposes.

     Software signals made available to users 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
     (sig) is illegal, ssignal returns SIG_DFL.

     gsignal raises the signal identified by its argument, sig:

          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 0 and takes no other action.

          If sig has an illegal value or no action was ever
          specified for sig, gsignal returns the value 0 and
          takes no other action.




January 1992                                                    1

ssignal(3C)                                           ssignal(3C)



NOTES
     There are some additional signals with numbers outside the
     range 1 through 15 that are used by the Standard C Library
     to indicate error conditions.  Thus, some signal numbers
     outside the range 1 through 15 are legal, although their use
     may interfere with the operation of the Standard C Library.

SEE ALSO
     sigvec(2), signal(3)














































2                                                    January 1992