## stream data from files## Copyright © 2000 Vita Nuova Limited.  All rights reserved.# implement Stream; include "sys.m";	sys: Sys;include "draw.m"; Stream: module{	init:	fn(nil: ref Draw->Context, argv: list of string);}; stderr: ref Sys->FD; usage(){	sys->fprint(stderr, "Usage: stream [-a] [-b bufsize] file1 [file2]\n");	fail("usage");} init(nil: ref Draw->Context, argv: list of string){	sys = load Sys Sys->PATH;	stderr = sys->fildes(2); 	bsize := 0;	sync := chan of int;	if(argv != nil)		argv = tl argv;	for(; argv != nil && len hd argv && (s := hd argv)[0] == '-' && len s > 1; argv = tl argv)		case s[1] {		'b' =>			if(len s > 2)				bsize = int s[2:];			else if((argv = tl argv) != nil)				bsize = int hd argv;			else				usage();		'a' =>			sync = nil;		* =>			usage();		}	if(bsize <= 0 || bsize > 2*1024*1024)		bsize = Sys->ATOMICIO;	argc := len argv;	if(argc < 1)		usage(); 	if(argc > 1){		f1 := eopen(hd argv, Sys->ORDWR);		f2 := eopen(hd tl argv, Sys->ORDWR);		spawn stream(f1, f2, bsize, sync);		spawn stream(f2, f1, bsize, sync);	}else{		f2 := sys->fildes(1);		if(f2 == nil) {			sys->fprint(stderr, "stream: can't access standard output: %r\n");			fail("stdout");		}		f1 := eopen(hd argv, Sys->OREAD);		spawn stream(f1, f2, bsize, sync);	}	if(sync != nil){	# count them back in		<-sync;		if(argc > 1)			<-sync;	}} stream(source: ref Sys->FD, sink: ref Sys->FD, bufsize: int, sync: chan of int){	if(sys->stream(source, sink, bufsize) < 0)		sys->fprint(stderr, "stream: error streaming data: %r\n");	if(sync != nil)		sync <-= 1;} eopen(name: string, mode: int): ref Sys->FD{	fd := sys->open(name, mode);	if(fd == nil){		sys->fprint(stderr, "stream: can't open %s: %r\n", name);		fail("open");	}	return fd;} fail(s: string){	raise s;	exit;}