implement Fsmodule;include "sys.m";	sys: Sys;include "draw.m";include "sh.m";include "fslib.m";	fslib: Fslib;	Report, Value, type2s, quit: import fslib;	Fschan, Fsdata, Entrychan, Entry,	Gatechan, Gatequery, Nilentry, Option,	Next, Down, Skip, Quit: import Fslib; # XXX implement octal modes. User:	con 8r700;Group:	con 8r070;Other:	con 8r007;All:	con User | Group | Other; Read:	con 8r444;Write:	con 8r222;Exec:	con 8r111; types(): string{	return "ps";} badmod(p: string){	sys->fprint(sys->fildes(2), "fs: size: cannot load %s: %r\n", p);	raise "fail:bad module";} init(){	sys = load Sys Sys->PATH;	fslib = load Fslib Fslib->PATH;	if(fslib == nil)		badmod(Fslib->PATH);} run(nil: ref Draw->Context, nil: ref Report,			nil: list of Option, args: list of ref Value): ref Value{	spec := (hd args).s().i;	(ok, mask, mode) := parsemode(spec);	if(ok == 0){		sys->fprint(sys->fildes(2), "fs: mode: bad mode %#q\n", spec);		return nil;	}	c := chan of Gatequery;	spawn modegate(c, mask, mode);	return ref Value.P(c);} modegate(c: Gatechan, mask, mode: int){	m := mode & mask;	while((((d, nil, nil), reply) := <-c).t0.t0 != nil)		reply <-= ((d.mode & mask) ^ m) == 0;} # stolen from /appl/cmd/chmod.bparsemode(spec: string): (int, int, int){	mask := Sys->DMAPPEND | Sys->DMEXCL | Sys->DMDIR | Sys->DMAUTH;loop:	for(i := 0; i < len spec; i++){		case spec[i] {		'u' =>			mask |= User;		'g' =>			mask |= Group;		'o' =>			mask |= Other;		'a' =>			mask |= All;		* =>			break loop;		}	}	if(i == len spec)		return (0, 0, 0);	if(i == 0)		mask |= All; 	op := spec[i++];	if(op != '+' && op != '-' && op != '=')		return (0, 0, 0); 	mode := 0;	for(; i < len spec; i++){		case spec[i]{		'r' =>			mode |= Read;		'w' =>			mode |= Write;		'x' =>			mode |= Exec;		'a' =>			mode |= Sys->DMAPPEND;		'l' =>			mode |= Sys->DMEXCL;		'd' =>			mode |= Sys->DMDIR;		'A' =>			mode |= Sys->DMAUTH;		* =>			return (0, 0, 0);		}	}	if(op == '+' || op == '-')		mask &= mode;	if(op == '-')		mode = ~mode;	return (1, mask, mode);}