title: Proper way to chain signal handlers in linux?
body: <p>I've got a couple signal handlers I'm using to exit my program cleanly, and I'd like to play nicely with whatever else has hooked them by chaining the signal handlers calls.  I'm using sigaction per the man page for signal saying it's not preferred anymore. </p>
  
  <p>Looking at the sigaction struct, there's signal masks and such that are specified, along with several flags.  What's the "right" way to call the currently installed handler so that all those options are taken into account?</p>