fix: 修复upf5002 telnet消息返回延迟导致命令行为不一致

src/modules/trace/service/tcpdump.go

@@ -230,6 +230,7 @@ func (s *TCPdump) UPFTrace(neType, neId, cmdStr string) (string, error) {
 		return "", err
 	}
 	defer telnetClient.Close()
+	telnetClient.RunCMD("") // 再次排空信息
 
 	// 命令拼装
 	fileName := fmt.Sprintf("%s_%s_part_%s.pcap ", neInfo.NeType, neInfo.NeId, time.Now().Format("20060102150405"))
@@ -250,11 +251,11 @@ func (s *TCPdump) UPFTrace(neType, neId, cmdStr string) (string, error) {
 
 	// 结果截取
 	arr := strings.Split(output, "\r\n")
-	if len(arr) == 2 {
+	if len(arr) < 2 {
 		return "", fmt.Errorf("trace pacp run failed")
 	}
-	if len(arr) > 3 {
-		resMsg := arr[2]
+	if len(arr) == 3 {
+		resMsg := arr[1]
 		// pcap trace: unknown input `f file UPF_001_part_2024-08-19...'
 		// pcap trace: dispatch trace already enabled...
 		// pcap trace: dispatch trace already disabled...