PHPOffice / PhpSpreadsheet

     * @param string $subData

     * @return array

     */

    private function readByteStringShort($subData)

    {

        // offset: 0; size: 1; length of the string (character count)

        $ln = ord($subData[0]);

        // offset: 1: size: var; character array (8-bit characters)

        $value = $this->decodeCodepage(substr($subData, 1, $ln));

        return [

            'value' => $value,

            'size' => 1 + $ln, // size in bytes of data structure

        ];

    }

    /**

     * Read byte string (16-bit string length)

     * @param string $subData

     * @return array

     */

    private function readByteStringLong($subData)

    {

        // offset: 0; size: 2; length of the string (character count)

        $ln = self::getInt2d($subData, 0);

        // offset: 2: size: var; character array (8-bit characters)

        $value = $this->decodeCodepage(substr($subData, 2));

        //return $string;

        return [

            'value' => $value,

            'size' => 2 + $ln, // size in bytes of data structure

        ];

    }

    /**

     * Extracts an Excel Unicode short string (8-bit string length)