Pastey filesize error

--
 --- build a file over 2^32 bytes as a test 
 -- 
 -- in this case, readfile is 2.6 gigabytes, so read once,  
 --   write twice should give a 5.2Gbyte file...... 
  
include std/filesys.e -- for dir()  
include std/console.e -- any_key 
  
puts(1,"running\n") 
object readfile = open("D:\\ngrams\\Co-5grams.txt","rb") 
object writefile = open("D:\\ngrams\\bigfile.txt","ab") 
object readline = "" 
 
  
readline = gets(readfile) 
while not equal(readline,-1) do 
  puts(writefile,readline) -- it should still have the \n on it as read 
  puts(writefile,readline) -- it should still have the \n on it as read 
  readline = gets(readfile) 
end while 
  
close(readfile) 
  
readline = dir("D:\\ngrams\\bigfile.txt") 
readline = sprintf("%d",readline[1][3]) 
puts(1,"Before closing: "&readline&"\n") 
 
close(writefile) 
  
readline = dir("D:\\ngrams\\bigfile.txt") 
readline = sprintf("%d",readline[1][3])  
puts(1,"After closing: "&readline&"\n") 
 
any_key("Press Any Key to quit"