allow add_input_event_hook to accept function handles * input.cc (base_hook_function, hook_function, named_hook_function, fcn_handle_hook_function): New classes. (input_event_hook, Fadd_input_event_hook, Fremove_input_event_hook): Use hook_function object. (Fadd_input_event_hook): Return hook_function ID. (Fremove_input_event_hook): Use ID to search for hook_function. * input.h, input.cc (remove_input_event_hook_functions): New function. * toplev.cc (do_octave_atexit): Call it.

--- a/libinterp/interpfcn/input.h
+++ b/libinterp/interpfcn/input.h
@@ -59,6 +59,8 @@
 
 extern octave_value do_keyboard (const octave_value_list& args = octave_value_list ());
 
+extern void remove_input_event_hook_functions (void);
+
 extern std::string VPS4;
 
 extern char Vfilemarker;