#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 <string.h>

char getVal(int argc, char * argv[])
{
    int val = 0xFF;
    if (argc >= 2)
    {
        if (strlen(argv[1]) >= 2 && strncmp(argv[1], "0x", 2) == 0)
        {
            sscanf(argv[1] + 2, "%x", &val);
        }
        else
        {
            sscanf(argv[1], "%d", &val);
        }
    }
    else
    {
        printf("Value not specified, using 0x%x\n", val);
    }
    return val;
}

int main(int argc, char * argv[])
{
    int fd;
    int result;
    char val = getVal(argc, argv);

    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;
    }

    ioctl(fd, PPWDATA, &val);

    printf("Releasing parallel port\n");
    ioctl(fd, PPRELEASE);
    close(fd);
    return 0;
}