Across USB with UART

			int fd0 = serial_setup();
			if(fd0==0)
			{
				fd = open(DEVICE, O_RDWR | O_NOCTTY | O_NDELAY);
				cfsetispeed(&toptions, BAUDRATE); // sets the input baud rate
				cfsetospeed(&toptions, BAUDRATE); // sets the output baud rate
				tcflush(fd, TCIOFLUSH); // flush data received but not read, and data written but not transmitted
			}

int serial_setup()
{
	static char* USER;
	static char CONFIG_FILE[100];
	USER = getenv("USERNAME");;
	if(USER == NULL)  
	{
		return -1;
	}

	strcpy(CONFIG_FILE, "/home/");
	strcat(CONFIG_FILE, USER);
	strcat(CONFIG_FILE, "/linuxcnc/nc_files/programme+/halcomps/arduinocontroller_device");

	FILE* fdConfig = fopen(CONFIG_FILE, "r");
	if(fdConfig == NULL)  
	{
		return -1;
	}
	fgets(DEVICE, sizeof(DEVICE), fdConfig);
	DEVICE[strlen(DEVICE)-1] = '\0';
	fscanf(fdConfig, "%i", &BAUDRATE);
	fclose(fdConfig);
	return 0;
}