#include <stdio.h>
#include <stdlib.h>
#include <sys/io.h>

#define IO_FREE 0
#define IO_KEEP 1

/* output I/O port */
void outp(unsigned short addr,unsigned char data)
{
    outb(data,addr);
}

/* Init I/O port */
int keepPort(unsigned short addr)
{
  if(ioperm(addr,1,IO_KEEP) != 0){
    printf("Error:Can not access I/O port. Must be root.\n");
    exit(1);
  }
}

/* Init I/O port */
int freePort(unsigned short addr)
{
  if(ioperm(addr,1,IO_FREE) != 0){
    printf("Error:Can not access I/O port. Must be root.\n");
    exit(1);
  }
}

int main(int argv, char **argc)
{
    unsigned short addr;	/* default addr 0x378 */
    unsigned char data;

    switch(argv){
    case 2:
	addr = 0x378;
	break;
    case 3:
	addr = (unsigned short)strtol(argc[2], (char**)NULL, 16);
	break;
    default:
	printf("Usage: paraport PORT_DATA [PORT_ADDR]\n");
	return 0;
    }

    data = (unsigned char)strtol(argc[1], (char**)NULL, 16);
    printf("PORT_ADDR:0x%04X PORT_DATA:0x%02X\n", addr, data);
    
    keepPort(addr);
    outp(addr, data);
    freePort(addr);

    return 0;
}