更现代的方法是使用
http_negotiate_language()：
$map = array("en" => "english", "es" => "spanish");
$conf_language= $map[ http_negotiate_language(array_keys($map)) ];
/*
determine which language out of an available set the user prefers most
$available_languages array with language-tag-strings (must be lowercase) that are available
$http_accept_language a HTTP_ACCEPT_LANGUAGE string (read from $_SERVER['HTTP_ACCEPT_LANGUAGE'] if left out)
*/
function prefered_language ($available_languages,$http_accept_language="auto") {
// if $http_accept_language was left out, read it from the HTTP-Header
if ($http_accept_language == "auto") $http_accept_language = isset($_SERVER['HTTP_ACCEPT_LANGUAGE']) ? $_SERVER['HTTP_ACCEPT_LANGUAGE'] : '';
// standard for HTTP_ACCEPT_LANGUAGE is defined under
// http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.4
// pattern to find is therefore something like this:
// 1#( language-range [ ";" "q" "=" qvalue ] )
// where:
// language-range = ( ( 1*8ALPHA *( "-" 1*8ALPHA ) ) | "*" )
// qvalue = ( "0" [ "." 0*3DIGIT ] )
// | ( "1" [ "." 0*3("0") ] )
preg_match_all("/([[:alpha:]]{1,8})(-([[:alpha:]|-]{1,8}))?" .
"(\s*;\s*q\s*=\s*(1\.0{0,3}|0\.\d{0,3}))?\s*(,|$)/i",
$http_accept_language, $hits, PREG_SET_ORDER);
// default language (in case of no hits) is the first in the array
$bestlang = $available_languages[0];
$bestqval = 0;
foreach ($hits as $arr) {
// read data from the array of this hit
$langprefix = strtolower ($arr[1]);
if (!empty($arr[3])) {
$langrange = strtolower ($arr[3]);
$language = $langprefix . "-" . $langrange;
}
else $language = $langprefix;
$qvalue = 1.0;
if (!empty($arr[5])) $qvalue = floatval($arr[5]);
// find q-maximal language
if (in_array($language,$available_languages) && ($qvalue > $bestqval)) {
$bestlang = $language;
$bestqval = $qvalue;
}
// if no direct hit, try the prefix only but decrease q-value by 10% (as http_negotiate_language does)
else if (in_array($langprefix,$available_languages) && (($qvalue*0.9) > $bestqval)) {
$bestlang = $langprefix;
$bestqval = $qvalue*0.9;
}
}
return $bestlang;
}
?>