linux command for def. gateway

pipe_test_with_routing.cpp

@@ -16,6 +16,8 @@ int main(int argc, char *argv[])
 		"route print -4 | findstr /r \"[^0-9]0\\.0\\.0\\.0\" ", "r"
 	);
 #elif defined ( Q_OS_LINUX )
+	// a guess: netstat -rn | grep "^0\.0\.0\.0" | awk '{print $2}' 
+	// w/o awk: netstat -rn | sed -rn 's/^0\.0\.0\.0\s+([^ ]+).*/\1/p'
 #else
 #error "We do not support this version."
 #endif