function getPreferredLanguage() {
$langs = array();
if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
// break up string into pieces (languages and q factors)
preg_match_all('/([a-z]{1,8}(-[a-z]{1,8})?)\s*(;\s*q\s*=\s*(1|0\.[0-9]+))?/i',
$_SERVER['HTTP_ACCEPT_LANGUAGE'], $lang_parse);
if (count($lang_parse[1])) {
// create a list like "en" => 0.8
$langs = array_combine($lang_parse[1], $lang_parse[4]);
// set default to 1 for any without q factor
foreach ($langs as $lang => $val) {
if ($val === '') $langs[$lang] = 1;
}
// sort list based on value
arsort($langs, SORT_NUMERIC);
}
}
//extract most important (first)
foreach ($langs as $lang => $val) { break; }
//if complex language simplify it
if (stristr($lang,"-")) {$tmp = explode("-",$lang); $lang = $tmp[0]; }
return $lang;
}