WWW to non-WWW Redirect with PHP

[BONLAVDON]

I want to redirect all www.domain.com requests to domain.com with PHP, basically:\[code\]if (substr($_SERVER['SERVER_NAME'], 0, 4) === 'www.'){ header('Location: http://' . substr($_SERVER['SERVER_NAME'], 4)); exit();}\[/code\]However I do want to maintain the requested URL like in SO, for e.g.:\[code\]http://www.stackoverflow.com/questions/tagged/php?foo=bar\[/code\]Should redirect to:\[code\]http://stackoverflow.com/questions/tagged/php?foo=bar\[/code\]I don't want to rely on \[code\].htaccess\[/code\] solutions, and I'm unsure which \[code\]$_SERVER\[/code\] vars I'd have to use to make this happen. Also, preserving the HTTPS protocol would be a plus.How should I do this?