function faviconCheck($ico)
{
if (substr($ico, 0, 3) == 'GIF' || substr($ico, 6, 4) == 'JFIF' || substr($ico, 1, 3) == 'PNG') {
return true;
}
/* It could be a BMP. It would then start with 'BM',
* followed by a magic 0 after 6 bytes and a magic 40 after
* 14 bytes (see http://www.daubnet.com/formats/BMP.html)
*/
if (strlen($ico) >= 40 && substr($ico, 0, 2) == 'BM' && SB_PageParser::bigEndianBin2long(substr($ico, 6, 4)) == 0 && SB_PageParser::bigEndianBin2long(substr($ico, 14, 4)) == 40) {
// Highly probable that this is really a BMP
return true;
}
/* It could also be ICO-format. It would then start with
* a leading zero, followed by a magic 1.
* (see http://www.daubnet.com/formats/ICO.html)
*/
if (strlen($ico) >= 4 && SB_PageParser::bigEndianBin2short(substr($ico, 0, 2)) == 0 && SB_PageParser::bigEndianBin2short(substr($ico, 2, 2)) == 1) {
// Check for the magic 40 after some header bytes
$offset = SB_PageParser::bigEndianBin2short(substr($ico, 4, 2)) * 16;
if (SB_PageParser::bigEndianBin2long(substr($ico, 6 + $offset, 4)) == 40) {
// Highly probable that this is really an ICO
return true;
}
}
return false;
}
