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

#define SZBUF 256

int main(int argc, char const *argv[]){
	int fd,n,l,x;
	long int i, offset;
	if (argc<3){
		fprintf(stderr,"Usage : %s <file_name> <offset> \r",argv[0]);
		exit (1);
	} fd=open (argv[1], O_RDONLY);
	if (fd==-1){
		perror("Opening destination file fails");
		exit (2);
	} i=strtol(argv[2],NULL,0);
	offset=i*(sizeof(int));
	l=lseek(fd,offset,SEEK_SET);
	if(l==1){
		perror("lsink failed");
		close(fd);
		exit (3);
	}
	n=read(fd,&x,sizeof(int));
	if(n==-1){
		perror("Read in file failed");
		close(fd);
		exit (4);
	} if(n==0){
		printf("Out of range\n");
	} else{
		printf("The number at offset %ld is 0x%08x --> %d \n",i,x,x);
	} close(fd);
	exit(0);
}