Code to control LPT port with C (based on https://www.howtoforge.com/tutorial/accessing-parallel-ports-on-linux/)

lpt_controller.c

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

#define base 0x378           /* parallel port base address */

int main(){
	int y;
	if (ioperm(base,1,1)){
		fprintf(stderr, "Access denied to %x\n", base); 
		exit(1);
	}
	/* Send 00000000 to parallel port to clear all bits */
	outb(0x00, base);
	/* Send 00001111 to parallel port */
	outb(0xF0, base);
	scanf("%d", &y);
	return 0;
}