fix csv output with newline instead of endl to avoid forced flush

srsue/hdr/metrics_csv.h

@@ -47,6 +47,7 @@ class metrics_csv : public srslte::metrics_listener<ue_metrics_t>
 {
 public:
   metrics_csv(std::string filename);
+  ~metrics_csv();
 
   void set_periodicity(float metrics_report_period_sec);
   void set_metrics(ue_metrics_t &m);

srsue/src/main.cc

@@ -404,7 +404,7 @@ void *input_loop(void *m) {
   while (running) {
     cin >> key;
     if (cin.eof() || cin.bad()) {
-      cout << "Closing stdin thread\n" << endl;
+      cout << "Closing stdin thread." << endl;
       break;
     } else {
       if ('t' == key) {

srsue/src/metrics_csv.cc

@@ -46,7 +46,16 @@ metrics_csv::metrics_csv(std::string filename)
   ,metrics_report_period(1.0)
   ,ue(NULL)
 {
-  file.open(filename.c_str());
+  file.open(filename.c_str(), std::ios_base::out);
+}
+
+metrics_csv::~metrics_csv()
+{
+  if (file.is_open()) {
+    file << "#eof\n";
+    file.flush();
+    file.close();
+  }
 }
 
 void metrics_csv::set_ue_handle(ue_metrics_interface *ue_)
@@ -62,7 +71,7 @@ void metrics_csv::set_metrics(ue_metrics_t &metrics)
 {
   if (file.is_open() && ue != NULL) {
     if(n_reports == 0) {
-      file << "time;rsrp;pl;cfo;dl_mcs;dl_snr;dl_turbo;dl_brate;dl_bler;ul_mcs;ul_buff;ul_brate;ul_bler;rf_o;rf_u;rf_l;is_attached" << endl;
+      file << "time;rsrp;pl;cfo;dl_mcs;dl_snr;dl_turbo;dl_brate;dl_bler;ul_mcs;ul_buff;ul_brate;ul_bler;rf_o;rf_u;rf_l;is_attached\n";
     }
     file << (metrics_report_period*n_reports) << ";";
     file << float_to_string(metrics.phy.dl.rsrp, 2);
@@ -89,7 +98,7 @@ void metrics_csv::set_metrics(ue_metrics_t &metrics)
     file << float_to_string(metrics.rf.rf_u, 2);
     file << float_to_string(metrics.rf.rf_l, 2);
     file << (ue->is_attached() ? "1.0" : "0.0");
-    file << endl;
+    file << "\n";
 
     n_reports++;
   } else {