function parsePPT($filename) {     // This approach uses detection of the string "chr(0f).Hex_value.chr(0x00).chr(0x00).chr(0x00)" to find text strings, which are then terminated by another NUL chr(0x00). [1] Get text between delimiters [2]     $fileHandle = fopen($filename, "r");    $line = fread($fileHandle, filesize($filename));    $lines = explode(chr(0x0f),$line);    $outtext = '';    foreach($lines as $thisline) {        if (strpos($thisline, chr(0x00).chr(0x00).chr(0x00)) == 1) {            $text_line = substr($thisline, 4);            $end_pos   = strpos($text_line, chr(0x00));            $text_line = substr($text_line, 0, $end_pos);            $text_line = preg_replace("/[^a-zA-Z0-9\s\,\.\-\n\r\t@\/\_\(\)]/"," ",$text_line);            if (strlen($text_line) > 1) {                $outtext.= substr($text_line, 0, $end_pos)."\n";            }        }    }    return $outtext;}$filename = "test_pptk.ppt";$ppt_string = parsePPT($filename);