first commit

internal/check.go

@@ -0,0 +1,24 @@
+package internal
+
+import (
+	"fmt"
+	"net"
+	"time"
+)
+
+func Check(destination, port string) string {
+	address := destination + ":" + port
+	timeout := 5 * time.Second
+	var status string
+	conn, err := net.DialTimeout("tcp", address, timeout)
+	if err != nil {
+		status = fmt.Sprintf("[下线] %s 无法访问 %v", destination, err)
+		return status
+	}
+	defer func(conn net.Conn) {
+		_ = conn.Close()
+	}(conn)
+
+	status = fmt.Sprintf("[上线] %s 访问正常\n从: %s\n到: %s", destination, conn.LocalAddr(), conn.RemoteAddr())
+	return status
+}