add chapter 15.11 (#688)

eBook/examples/chapter_15/websocket_client.go

@@ -0,0 +1,29 @@
+// websocket_client.go
+package main
+
+import (
+	"fmt"
+	"time"
+	"code.google.com/p/go.net/websocket"
+)
+
+func main() {
+	ws, err := websocket.Dial("ws://localhost:12345/websocket", "",
+		"http://localhost/")
+	if err != nil {
+		panic("Dial: " + err.Error())
+	}
+	go readFromServer(ws)
+	time.Sleep(5e9)
+    ws.Close()
+}
+
+func readFromServer(ws *websocket.Conn) {
+	buf := make([]byte, 1000)
+	for {
+		if _, err := ws.Read(buf); err != nil {
+			fmt.Printf("%s\n", err.Error())
+			break
+		}
+	}
+}