PHP URL shortening functions

Integer konvertavimas.

Jigu tinka - ir _ simboliai

function encode($number) {
    return strtr(rtrim(base64_encode(pack('i', $number)), '='), '+/', '-_');
}
function decode($base64) {
    $number = unpack('i', base64_decode(str_pad(strtr($base64, '-_', '+/'), strlen($base64) % 4, '=')));
    return $number[1];
}

jeigu norima tik raidyno ir skaiciu

1. function encode($val, $base=62, $chars='0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ') {
2. // can't handle numbers larger than 2^31-1 = 2147483647
3. $str = '';
4. do {
5. $i = $val % $base;
6. $str = $chars[$i] . $str;
7. $val = ($val - $i) / $base;
8. } while($val > 0);
9. return $str;
10. } 
12. function decode($str, $base=62, $chars='0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ') {
13. $len = strlen($str);
14. $val = 0;
15. $arr = array_flip(str_split($chars));
16. for($i = 0; $i < $len; ++$i) {
17. $val += $arr[$str[$i]] * pow($base, $len-$i-1);
18. }
19. return $val;
20. }

paprastam url konvertavimui

function base64url_encode($data) {
  return rtrim(strtr(base64_encode($data), '+/', '-_'), '=');
}

function base64url_decode($data) {
  return base64_decode(str_pad(strtr($data, '-_', '+/'), strlen($data) % 4, '=', STR_PAD_RIGHT));
}