framework/i18n/GettextMoFile.php
protected function readString($fileHandle, $length, $offset = null)
    {
        if ($offset !== null) {
            fseek($fileHandle, $offset);
        }

        return $this->readBytes($fileHandle, $length);
    }
protected function readString($fileHandle, $length, $offset = null)
    {
        if ($offset !== null) {
            fseek($fileHandle, $offset);
        }

        return $this->readBytes($fileHandle, $length);
    }
Reads a string.
@param resource $fileHandle file handle
@param int $length of the string
@param int $offset of the string in the file. If null, it reads from the current position.
@return string the result