Foxbrush

The following code will parse $_SERVER['HTTP_ACCEPT_LANGUAGE'], 
en-ca,en;q=0.8,en-us;q=0.6,de-de;q=0.4,de;q=0.2,
into an array.

/* == Code == */ $langs = array();
if (isset($_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);
}
}

// look through sorted list and use first one that matches our languages
foreach ($langs as $lang => $val) {
if (strpos($lang, 'de') === 0) {
// show German site
} else if (strpos($lang, 'en') === 0) {
// show English site
}
}
// show default site or prompt for language

/* == Output == */
// Key = Accept-lang; Value = The fitting degree
Array
(
[en-ca] => 1
[en] => 0.8
[en-us] => 0.6
[de-de] => 0.4
[de] => 0.2
)