ssignal(3C)            UNIX System V(C Development Set)             ssignal(3C)


NAME
      ssignal, gsignal - software signals

SYNOPSIS
      #include <signal.h>

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

      int gsignal (int sig);

DESCRIPTION
      ssignal and gsignal implement a software facility similar to signal(2).
      This facility is made available to users for their own purposes.

      Software signals made available to users are associated with integers in
      the inclusive range 1 through 17. 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 SIGDFL (default) or SIGIGN (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 SIGDFL.

      gsignal raises the signal identified by its argument, sig:

           If an action function has been established for sig, then that action
           is reset to SIGDFL 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 SIGIGN, gsignal returns the value 1 and
           takes no other action.

           If the action for sig is SIGDFL, 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.

SEE ALSO
      signal(2), sigset(2), raise(3C).








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