Scieneer Common Lisp 1.3.9 online documentation

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.