add more tests

add network capability to example app

cmd/zplgfa/network.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"fmt"
+	"net"
+)
+
+func sendDataToZebra(ip, port, str string) error {
+	tcpAddr, err := net.ResolveTCPAddr("tcp", ip+":"+port)
+	conn, err := net.DialTCP("tcp4", nil, tcpAddr)
+	if err == nil {
+		defer conn.Close()
+
+		payloadBytes := []byte(fmt.Sprintf("%s\r\n\r\n", str))
+		_, err = conn.Write(payloadBytes)
+		return err
+	}
+	return err
+}
+
+func sendFeedCmdToZebra(ip, port string) error {
+	return sendDataToZebra(ip, port, "^xa^aa^fd ^fs^xz")
+}
+
+func sendCalibCmdToZebra(ip, port string) error {
+	return sendDataToZebra(ip, port, "~jc^xa^jus^xz")
+}