implement Styxmon; include "sys.m";	sys: Sys;include "draw.m";include "styx.m";	styx: Styx;	Tmsg, Rmsg: import styx;include "sh.m";include "arg.m"; Styxmon: module {	init: fn(nil: ref Draw->Context, argv: list of string);}; badmod(p: string){	sys->fprint(sys->fildes(2), "styxmon: cannot load %s: %r\n", p);	raise "fail:bad module";} showdata := 0;init(ctxt: ref Draw->Context, argv: list of string){	sys = load Sys Sys->PATH;	styx = load Styx Styx->PATH;	if(styx == nil)		badmod(Styx->PATH);	styx->init();	arg := load Arg Arg->PATH;	if(arg == nil)		badmod(Arg->PATH);	arg->init(argv);	arg->setusage("usage: styxmon [-d] cmd [arg...]");	while((opt := arg->opt()) != 0){		case opt{		'd' =>			showdata = 1;		* =>			arg->usage();		}	}	argv = arg->argv();	if(argv == nil)		arg->usage();	fd0 := sys->fildes(0);	fd1 := popen(ctxt, argv);	sync := chan of int;	spawn msgtx(fd0, fd1, sync, "tmsg");	<-sync;	spawn msgtx(fd1, fd0, sync, "rmsg");	<-sync;} msgtx(f0, f1: ref Sys->FD, sync: chan of int, what: string){	sys->pctl(Sys->NEWFD|Sys->NEWNS, 2 :: f0.fd :: f1.fd :: nil);	sync <-= 1;	f0 = sys->fildes(f0.fd);	f1 = sys->fildes(f1.fd);	stderr := sys->fildes(2);	for (;;) {		(d, err) := styx->readmsg(f0, 0);		if(d == nil){			if(err != nil)				sys->fprint(stderr, "styxmon: error from %s: %s\n", what, err);			else				sys->fprint(stderr, "styxmon: eof from %s\n", what);			exit;		}		if(styx->istmsg(d)){			(n, m) := Tmsg.unpack(d);			if(n != len d){				sys->fprint(stderr, "styxmon: %s message error (%d/%d)\n", what, n, len d);			}else{				sys->fprint(stderr, "%s\n", m.text());			}		}else{			(n, m) := Rmsg.unpack(d);			if(n != len d){				sys->fprint(stderr, "styxmon: %s message error (%d/%d)\n", what, n, len d);				if(m != nil)					sys->fprint(stderr, "err: %s\n", m.text());			}else{				sys->fprint(stderr, "%s\n", m.text());			}		}		sys->write(f1, d, len d);	}} popen(ctxt: ref Draw->Context, argv: list of string): ref Sys->FD{	sync := chan of int;	fds := array[2] of ref Sys->FD;	sys->pipe(fds);	spawn runcmd(ctxt, argv, fds[0], sync);	<-sync;	return fds[1];} runcmd(ctxt: ref Draw->Context, argv: list of string, stdin: ref Sys->FD, sync: chan of int){	sys->pctl(Sys->FORKFD, nil);	sys->dup(stdin.fd, 0);	stdin = nil;	sync <-= 0;	sh := load Sh Sh->PATH;	sh->run(ctxt, argv);}