Arch : module{	PATH : con "/dis/install/arch.dis"; 	Ahdr : adt {		name : string;		modestr : string;		d : ref Sys->Dir;	}; 	Archive : adt {		b : ref Bufio->Iobuf;		nexthdr : int;		canseek : int;		pid : int;		hdr : ref Ahdr;		err : string;	}; 	init: fn(bio: Bufio); 	openarch: fn(name : string) : ref Archive;	openarchfs: fn(name : string) : ref Archive;	openarchgz: fn(name : string) : (string, ref Sys->FD);	gethdr: fn(ar : ref Archive) : ref Ahdr;	getfile: fn(ar : ref Archive, bout : ref Bufio->Iobuf, n : int) : string;	drain: fn(ar : ref Archive, n : int) : int;	closearch: fn(ar : ref Archive); 	puthdr: fn(b : ref Bufio->Iobuf, name : string, d : ref Sys->Dir);	putstring: fn(b : ref Bufio->Iobuf, s : string);	putfile: fn(b : ref Bufio->Iobuf, f : string, n : int) : string;	putend: fn(b : ref Bufio->Iobuf); 	addperms: fn(p: int);};