sms_example.php

<?php
/**
 *
 * Inbound SMS
 */
function getSms($request)
{
    $h = fopen('sms.txt', 'w');
    if (isset($request['from_number'])) {
        foreach ($request as $k => $v) {
            fwrite($h, "$k: $v" . PHP_EOL);
        }
    }
    fclose($h);
}
getSms($_REQUEST);