/**
  * Read a multiline sql command from a file.
  *
  * Supports the formatting created by mysqldump, but won't handle multiline comments.
  * @param \BackupMigrate\Core\File\BackupFileReadableInterface $file
  * @return string
  */
 protected function _readSQLCommand(BackupFileReadableInterface $file)
 {
     $out = '';
     while ($line = $file->readLine()) {
         $first2 = substr($line, 0, 2);
         $first3 = substr($line, 0, 2);
         // Ignore single line comments. This function doesn't support multiline comments or inline comments.
         if ($first2 != '--' && ($first2 != '/*' || $first3 == '/*!')) {
             $out .= ' ' . trim($line);
             // If a line ends in ; or */ it is a sql command.
             if (substr($out, strlen($out) - 1, 1) == ';') {
                 return trim($out);
             }
         }
     }
     return trim($out);
 }