LibreX-fork/locale/localization.php

<?php

function printtext($key) {
    echo TEXTS[$key];
}

function printftext() {
    $argv = func_get_args();
    $key = array_shift($argv);
    return vprintf(TEXTS[$key], $argv);
}

// default to language "en"
$locale = "en";

if (array_key_exists("HTTP_ACCEPT_LANGUAGE", $_SERVER)) {
    $accept_language_header = $_SERVER['HTTP_ACCEPT_LANGUAGE'];

    foreach(explode(",", explode(";", $accept_language_header)[0]) as $header_language) {
        if (file_exists("locale/$header_language.php")) {
            $locale = $header_language;
            break;
        }
    }
}

define("TEXTS", require_once "locale/$locale.php");
?>