|sys:enable-interrupt signal handler||[Function]|
Enable a signal handler. The signal should be a valid signal number or a keyword of the standard UNIX signal name. Note that the signal :sigpwr is used by the lisp implementation and is not available. The handler may be either:
- Restore the default behaviour for the signal.
- Attempt to ignore the signal.
- A function
- The function to be called to handle the signal. For synchronous signals, the handler is called within the thread causing the signal, and is called with three arguments: the signal number, a SAP pointing to the siginfo structure, and a SAP pointing to the signal context. For asynchronous signals the handler is called from a new thread dedicated to handling the signal, and is passed just one argument, the signal number.