#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/parport.h>
#include <linux/ppdev.h>

#include <stdio.h>
#include <unistd.h>

#define PORT "/dev/parport0"

int pp_open(char *port);
int pp_close(int pp);
int pp_setdir(int pp, int direction);
int pp_setdata(int pp, char byte);


int main(int argc, char *argv[])
{
        int pp, chr;

        pp = pp_open(PORT);

        for (;;)
        {
                chr = getc(stdin);
                if (chr == 'T')
                {
                        pp_setdata(pp, 0xFF);
                        usleep(1000);
                        pp_setdata(pp, 0x00);
                }
                else if (chr == 'C')
                {
                        return 0;
                }
        }       

        pp_close(pp);
}

int pp_open(char *port)
{
        int pp; /* Parallel port file descriptor */
        int mode = IEEE1284_MODE_COMPAT; /* Set transfer mode; COMPAT, BYTE, NIBBLE, EPP or ECP */

        /* Open port */
        pp = open(port, O_RDWR);
        if (pp == -1)
                return pp;

        /* Claims access to the port, this fails if any other program have used PPEXCL. */
        if (ioctl(pp, PPCLAIM))
        {
                close(pp);
                return -1;
        }
        
        /* Set transfer mode, and do negotiation */
        if (ioctl(pp, PPNEGOT, &mode))
        {
                close(pp);
                return -1;
        }
        
        /* Return file descriptor, should be used when calling these functions later */
        return pp;
}

int pp_close(int pp)
{
        /* Release port and close file descriptor */
        ioctl(pp, PPRELEASE);
        return close(pp);
}

int pp_setdir(int pp, int direction)
{
        /* Set data direction forward/reverse */
        return ioctl(pp, PPDATADIR, direction);
}

int pp_setdata(int pp, char byte)
{
        /* Set data bits to byte */
        return ioctl(pp, PPWDATA, &byte);
}