Given an alphabetic string via stdin, will return columnar index

az.php

<?php

define('ALPHA', 'abcdefghijklmnopqrstuvwxyz');

$pow = $sum = 0;

foreach (array_reverse(str_split(trim(file_get_contents('php://stdin', 'r')))) as $char) {
  $sum += pow(strlen(ALPHA), $pow++) * (strpos(ALPHA, strtolower($char)) + 1);
}

print $sum . PHP_EOL;