Writing to a Remote file using FTP functions

$file_name = "data.txt";
$fp = fopen ( $file_name, 'r' );
if ($fp) {
  $data = fread ( $fp, filesize ( $file_name ) );
  fclose ( $fp );
  $file_name = "ftp://user:pass@ftp.somedomain.com/home/user/$file_name";
  $fp = fopen ( $file_name, 'wt' );
  if ($fp) {
    echo 'writing data';
    fwrite ( $fp, $data );
    fclose ( $fp );

  }
}