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

int main (int argc, char **argv) {

 int rf = open ("random.txt",O_RDWR | O_CREAT | O_APPEND ,0644);
/* write (rf,"You suck\n",9);
 lseek (rf,4,SEEK_SET);  //4 bytes from the beginning of the file
 write (rf,"d",1);*/
/*
 write (rf,"Ima",3); //Since I didn't erase anything, it just overwrote from the begining*/
/* for (char c = 'A'; c <= 'Z'; c++) {
  lseek (rf,0,SEEK_SET);
  write (rf,&c,1);
 }
 lseek (rf,4,SEEK_SET);
 char buf[5]; buf[4] = '\0';
 read (rf,buf,4);
 printf ("%s\n",buf);*/
 ftruncate (rf,9000);
 close (rf);
 return 0;
}