Does anybody know a PHP function for IMEI validation?
You can use this (witchcraft!) solution, and simply check the string length:
function is_luhn($n) {
$str = '';
foreach (str_split(strrev((string) $n)) as $i => $d) {
$str .= $i %2 !== 0 ? $d * 2 : $d;
}
return array_sum(str_split($str)) % 10 === 0;
}
function is_imei($n){
return is_luhn($n) && strlen($n) == 15;
}
Here's my original function that explains each step:
function is_imei($imei){
// Should be 15 digits
if(strlen($imei) != 15 || !ctype_digit($imei))
return false;
// Get digits
$digits = str_split($imei);
// Remove last digit, and store it
$imei_last = array_pop($digits);
// Create log
$log = array();
// Loop through digits
foreach($digits as $key => $n){
// If key is odd, then count is even
if($key & 1){
// Get double digits
$double = str_split($n * 2);
// Sum double digits
$n = array_sum($double);
}
// Append log
$log[] = $n;
}
// Sum log & multiply by 9
$sum = array_sum($log) * 9;
// Compare the last digit with $imei_last
return substr($sum, -1) == $imei_last;
}