Moving code from theme header to functions.php

I’d recommend moving this to a plugin, rather than doing it in the theme, and then activating it on the main site. The rule that I follow is that if it’s going to affect the look, it goes in the theme; if it’s affecting functionality, then it goes in a plugin. This, to my mind, is a functional thing.

wp-content/plugins/my-ms-redirector/my-ms-redirector.php:

<?php

/*
Plugin Name: My MS Redirector
Description: Redirects to /ie, /uk, etc based on geoip
*/

add_action( 'init', 'wpse206906_redirector' );

function wpse206906_redirector() {
    $url = $_SERVER['REQUEST_URI'];
    require_once("geoip.inc");
    $gi = geoip_open(dirname(__FILE__) . "/GeoIP.dat", GEOIP_STANDARD);
    $country_code = geoip_country_code_by_addr($gi, $_SERVER['REMOTE_ADDR']);
    geoip_close($gi);
    if ($url === "https://wordpress.stackexchange.com/") {
        //If IE go to /ie
        if ($country_code === "IE") {
            wp_redirect( 'http://www.wpmultisite.com/ie' ) ;
            exit();
        }//If GB go to /uk
        if ($country_code === "GB") {
            wp_redirect( 'http://www.wpmultisite.com/uk' );
            exit();
        }
    }
}

References

(I know that die() and exit() are functionally identical, but I tend to use exit() when I just want to end PHP execution, and die() when I want to throw an error. It’s a personal preference.)

References

Related Posts: