implement Exception; include "sys.m";	sys: Sys;include "exception.m"; getexc(pid: int): (int, string, string){	loadsys();	if(pid < 0)		pid = sys->pctl(0, nil);	f := "/prog/"+string pid+"/exception";	if((fd := sys->open(f, Sys->OREAD)) == nil)		return (0, nil, nil);	b := array[8192] of byte;	if((n := sys->read(fd, b, len b)) < 0)		return (0, nil, nil);	s := string b[0: n];	if(s == nil)		return (0, nil, nil);	(m, l) := sys->tokenize(s, " ");	if(m < 3)		return (0, nil, nil);	pc := int hd l;	l = tl l;	mod := hd l;	l = tl l;	exc := hd l;	l = tl l;	for( ; l != nil; l = tl l)		exc += " " + hd l;	return (pc, mod, exc);} setexcmode(mode: int): int{	loadsys();	pid := sys->pctl(0, nil);	f := "/prog/" + string pid + "/ctl";	if(mode == NOTIFYLEADER)		return write(f, "exceptions notifyleader");	else if(mode == PROPAGATE)		return write(f, "exceptions propagate");	else		return -1;} loadsys(){	if(sys == nil)		sys = load Sys Sys->PATH;} write(f: string, s: string): int{	if((fd := sys->open(f, Sys->OWRITE)) == nil)		return -1;	b := array of byte s;	if((n := sys->write(fd, b, len b)) != len b)		return -1;	return 0;}