I am implementing an algorithm to generate a key access to a certain system, however the need to convert a numeric value to 16-digit hexadecimal.
Consider the number of milliseconds since January 1, 1970:
$milliseconds = (time()*1000);
//1530747443000
Is it possible to convert the value in milliseconds to a 16-digit hexadecimal value?
According to the documentation , dechex() only supports integers with values up to 4294967295 .
In this case, you need to write a function that can convert large integers to hexadecimal, see:
<?php
function bcdechex($dec) {
$hex = '';
do {
$last = bcmod($dec, 16);
$hex = dechex($last).$hex;
$dec = bcdiv(bcsub($dec, $last), 16);
} while($dec>0);
return str_pad($hex, 16, "0", STR_PAD_LEFT);
}
$hexstr = bcdechex( time() * 1000 );
echo $hexstr;
?>
Output:
0000016467d83520
You can use Math/BigInteger to solve your problem and easily create a hexadecimal converter:
<?php
include('Math/BigInteger.php');
function toHex($n) {
$zero = new Math_BigInteger(0);
if ($n->compare($zero) == 0) return "0";
$base = "0123456789ABCDEF";
$dezesseis = new Math_BigInteger(16);
$result = "";
while ($n->compare($zero) > 0) {
list($n, $r) = $n->divide($dezesseis);
$result = $base[intval($r->toString())] . $result;
}
return $result;
}
function milliToHex() {
$temp = new Math_BigInteger(time());
$mil = new Math_BigInteger(1000);
$ret = toHex($temp->multiply($mil));
return str_pad($ret, 16, "0", STR_PAD_LEFT);
}
echo milliToHex();
?>
For me, it produced this output:
0000016468976E40
See here working on ideone (but do not be alarmed at the size of the code, as I had to copy and paste the whole Math/BigInteger class there in the ideone).
I've already done this answer three and a half years ago using some similar concepts.