only creates new log file when loging new data

groundStation/src/backend/backend.c

@@ -114,6 +114,7 @@ fd_set rfds_master;
 int max_fd = 0;
 
 static FILE * quadlog_file;
+static int quadlog_file_open;
 static char user_specified_log_name[256] = "";
 
 pthread_mutex_t quadResponseMutex, cliInputMutex ;
@@ -211,6 +212,7 @@ int main(int argc, char **argv)
 
 	printf("Creating log file '%s'...\n",log_file);
 	quadlog_file = fopen(log_file, "a");
+	quadlog_file_open = 1;
 
 	// Tell the quad we are ready to send it vrpn data
 	sendStartPacket();
@@ -795,6 +797,12 @@ static void quad_recv() {
 
 		switch (m.msg_type) {
 			case LOG_ID:
+				if (!quadlog_file_open) {
+					char log_file[256];
+					create_log_name(log_file, 256);
+					printf("New log file created: '%s'\n", log_file);
+					quadlog_file = fopen(log_file, "a");
+				}
 				/* something like this */
 				printf("(Quad) : Log found\n");
 				fwrite((char *) data, sizeof(char), m.data_len, quadlog_file);
@@ -808,11 +816,10 @@ static void quad_recv() {
 				handleResponse(&m, data);
 				break;
 			case LOG_END_ID:
-				fclose(quadlog_file);
-				char log_file[256];
-				create_log_name(log_file, 256);
-				printf("New log file created: '%s'\n", log_file);
-				quadlog_file = fopen(log_file, "a");
+				if (quadlog_file_open) {
+					fclose(quadlog_file);
+					quadlog_file_open = 0;	
+				}
 				break;
 			default:
 				printf("(Backend): message type %d ignored from quad\n", m.msg_type);