PHP fopen write to single line

<?php
$text = "Here is my new line.";
$newline = "$text\n"
$filename = $_SERVER['DOCUMENT_ROOT'] . "/myfile.php";
if (!($fp = fopen($filename, 'a'))) {
  print 'Cannot open file';
} else {
  if(fwrite($fp, "$newline")){
    print "line written<br />\n";
  } else {
    print "problem writing line\n";
  }
  if(fclose($fp)){
    print 'file closed';
  } else {
    print 'problem closing file';
  }
}
?>