<?php 
$handle = fopen("res.txt", "r"); 
$handle2 = fopen("result.txt", "a+"); 
$buffer = fgets($handle, 4096);
fwrite($handle2, $buffer);
while (!feof($handle)) { 
    $buf= fgets($handle, 4096);
    if($buf == $buffer)
      {
      } else
      {
        $buffer=$buf;
        fwrite($handle2, $buffer);
      }
    
} 
fclose($handle); 
fclose($handle2); 
?>