#include <stdio.h>
#include <sys/ioctl.h>
#include <linux/parport.h>
#include <linux/ppdev.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>

#define WAIT 100000

int running = 1;

void	signalHandler(int sig)
{
	running = 0;
}

int	main(void)
{
	int fd;
	int result;
	
	signal(SIGINT, signalHandler);
	
	fd = open("/dev/parport0", O_RDWR);
	
	if (fd == -1)
	{
		perror("Could not open parallel port");
		return 1;
	}
	
	printf("Claiming parallel port\n");
	if (ioctl(fd, PPCLAIM, NULL))
	{
		perror("Could not claim the parallel port!");
		close(fd);
		return 2;
	}
	
	int mode = IEEE1284_MODE_BYTE;
	if (ioctl(fd, PPSETMODE, &mode))
	{
		perror("Could not set mode");
		ioctl(fd, PPRELEASE);
		close(fd);
		return 3;
	}
	
	int dir = 0x00;
	if (ioctl(fd, PPDATADIR, &dir))
	{
		perror("Could not set parallel port direction");
		ioctl(fd, PPRELEASE);
		close(fd);
		return 4;
	}
	
	char dataH = 0xFF;
	char dataL = 0x00;
	
	for(;;)
	{
		ioctl(fd, PPWDATA, &dataH);
		usleep(WAIT);
		if (!running)
			break;
		ioctl(fd, PPWDATA, &dataL);
		usleep(WAIT);
		if (!running)
			break;
	}
	
	printf("Releasing parallel port\n");
	ioctl(fd, PPRELEASE);
	close(fd);
	return 0;
}