#include <iostream>     // so I don't have to do lo level io everywhere.
#include <unistd.h>     // close, and in general
#include <sys/types.h>  //read
#include <sys/stat.h>   //read
#include <fcntl.h>      //read
#include <stdio.h>      // perror

#include <climits>

using namespace std;

const char * filename = "fileHole";

int main() {

    int fd;
    int pos, bytes;
    char i;

    // more on this open soon.
    fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC,
                     S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH );
    if (-1 == fd) {
       perror("Open failed");
       return -1;
    }

    // write ten integers to the file.
    for(i='a';i<'j';i++) {
        bytes = write(fd, &i, sizeof(i));
	if (-1 == bytes) {
            perror("Write failed: ");
	}
    }

    pos = lseek(fd, 0, SEEK_CUR);
    if (-1 == pos) {
         perror("Seek failed with offset of 0:");
    } else {
         cout << "After writing we are at position " << pos << endl;
    }

    // now skip a block.
    pos = lseek(fd, 10*sizeof(i), SEEK_CUR);
    if (-1 == pos) {
        perror("Seek Failed: ");
    } else {
        cout << "Writing at position " << pos << endl;
        // put the 10.
        bytes = write(fd, &i, sizeof(i));
	if (-1 == bytes) {
	    perror("Writing at the end of a hole failed ");
	}
    }

    close(fd);

    return 0;
}