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@iSaadSalman
Last active September 9, 2017 02:44
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<?php
function alphaID($in, $to_num = false, $pad_up = false, $pass_key = null)
{
$out = '';
$index = 'abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';
$base = strlen($index);
if ($pass_key !== null) {
for ($n = 0; $n < strlen($index); $n++) {
$i[] = substr($index, $n, 1);
}
$pass_hash = hash('sha256',$pass_key);
$pass_hash = (strlen($pass_hash) < strlen($index) ? hash('sha512', $pass_key) : $pass_hash);
for ($n = 0; $n < strlen($index); $n++) {
$p[] = substr($pass_hash, $n, 1);
}
array_multisort($p, SORT_DESC, $i);
$index = implode($i);
}
if ($to_num) {
// Digital number <<-- alphabet letter code
$len = strlen($in) - 1;
for ($t = $len; $t >= 0; $t--) {
$bcp = bcpow($base, $len - $t);
$out = $out + strpos($index, substr($in, $t, 1)) * $bcp;
}
if (is_numeric($pad_up)) {
$pad_up--;
if ($pad_up > 0) {
$out -= pow($base, $pad_up);
}
}
} else {
// Digital number -->> alphabet letter code
if (is_numeric($pad_up)) {
$pad_up--;
if ($pad_up > 0) {
$in += pow($base, $pad_up);
}
}
for ($t = ($in != 0 ? floor(log($in, $base)) : 0); $t >= 0; $t--) {
$bcp = bcpow($base, $t);
$a = floor($in / $bcp) % $base;
$out = $out . substr($index, $a, 1);
$in = $in - ($a * $bcp);
}
}
return $out;
}
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