1 files changed, 61 insertions, 0 deletions
diff --git a/appl/alphabet/main/w2fd.b b/appl/alphabet/main/w2fd.b
new file mode 100644
index 00000000..ab7e3a70
--- /dev/null
+++ b/appl/alphabet/main/w2fd.b
@@ -0,0 +1,61 @@
+implement ToFD,Mainmodule;
+include "sys.m";
+	sys: Sys;
+include "draw.m";
+include "sh.m";
+include "alphabet/reports.m";
+	reports: Reports;
+	Report: import reports;
+include "alphabet.m";
+	alphabet: Alphabet;
+		Value: import alphabet;
+
+ToFD: module {};
+
+typesig(): string
+{
+	return "fw";
+}
+
+init()
+{
+	alphabet = load Alphabet Alphabet->PATH;
+	reports = load Reports Reports->PATH;
+}
+
+quit()
+{
+}
+
+run(nil: ref Draw->Context, r: ref Reports->Report, nil: chan of string,
+		nil: list of (int, list of ref Alphabet->Value),
+		args: list of ref Alphabet->Value): ref Alphabet->Value
+{
+	sys = load Sys Sys->PATH;
+	f := chan of ref Sys->FD;
+	spawn tofdproc(f, (hd args).w().i, r.start("2fd"));
+	return ref Value.Vf(f);
+}
+
+tofdproc(f, w: chan of ref Sys->FD, errorc: chan of string)
+{
+	fd0 := <-w;
+	f <-= fd0;
+	fd1 := <-f;
+	if(fd1 == nil)		# asked to quit? tell w to quit too.
+		w <-= nil;
+	else
+	if(fd0 == nil)		# no proposed fd? give 'em the one we've just got.
+		w <-= fd1;
+	else{				# otherwise one-way stream from w to f.
+		w <-= nil;
+		buf := array[Sys->ATOMICIO] of byte;
+		while((n := sys->read(fd0, buf, len buf)) > 0){
+			if(sys->write(fd1, buf, n) == -1){
+				reports->report(errorc, sys->sprint("write error: %r"));
+				break;
+			}
+		}
+	}
+	reports->quit(errorc);
+}