[WordPress] Handle PHP Version in WordPress

00-php-version-support.php

<?php

register_activation_hook(__FILE__, __NAMESPACE__ . '\\acme_activate');
/**
 * Verifies that the user is running the proper version of WordPress for the
 * plugin to execute; otherwise, displays an error message and prevents the
 * plugin from being activated.
 */
function acme_activate()
{
    if (version_compare(PHP_VERSION, '5.6.20', '<')) {
        wp_die(
            sprintf(
                'Acme requires PHP 5.6.20 or higher.
                Your WordPress site is using PHP %s. Please contact your hosting
                provider and ask that they upgrade the version of PHP on which
                your installation of WordPress is running. Click back in your
                browser to your WordPress dashboard.',
                PHP_VERSION
            )
        );
    }
}