Arguments: number function
function is made the signal handler for signal
number. It replaces the previous handler for the signal
instead of pushing a new handler on
*signals*.
The handling of operating system dependent signals generated during program execution is not part of Common Lisp. A signal is a small integer. The list of valid signals is given in a system dependent file, usually on UNIX something like /usr/include/signals.h. Signals are either synchronous or asynchronous, but there is no distinction made in this interface--the handling of both types of signals is the same. A handler for a signal is a function of two arguments, signal number and t. If there is no handler for a particular signal, then some default action is invoked, which is usually to signal an error. Signals handlers should return a true value if they handle the signal, so that other, nested handlers are not invoked to handle the signal. A signal that is posted during a gc is processed immediately after the gc finishes.
See add-signal-handler
(which has an example),
remove-signal-handler,
*signals*, and
with-signal-handler.
The documentation is described in introduction.htm and the index is in index.htm.
Copyright (c) 1998-2000, Franz Inc. Berkeley, CA., USA. All rights reserved.
Created 2000.10.5.