Availability:C-language interface function
void PL_on_halt(int 
(*f)(int, void *), void *closure)Register the function f to be called if SWI-Prolog is halted. 
The function is called with two arguments: the exit code of the process 
(0 if this cannot be determined) and the closure argument 
passed to the PL_on_halt() 
call. Handlers must return 0. Other return values are reserved 
for future use. See also at_halt/1.bugAlthough 
both PL_on_halt() 
and at_halt/1 
are called in FIFO order, all at_halt/1 
handlers are called before all PL_on_halt() 
handlers. These handlers are called before system 
cleanup and can therefore access all normal Prolog resources. See also PL_exit_hook().