prepis suboru

<?php
$filename = "1.txt";
$rewriteLine = 3;

if(!empty($_POST['retazec'])) {
   if(file_exists($filename)) {
      $content = @file($filename);
   
      $content[$rewriteLine-1] = $_POST['retazec']."\r\n";
      
      $fp = @fopen($filename,"w");
      foreach($content as $line) {
         @fwrite($fp, $line);
      }
      fclose($fp);
   }   
}
?>
<form method="post">
<input type="text" name="retazec" value=""><input type="submit" value="Rewrite">
</form>