php gets http headers

getallheaders() can get all http headers, but it can only be used on the apache server.
Use $_SERVER to encapsulate a general function.

function emu_getallheaders() { 
    foreach ($_SERVER as $name => $value) 
    { 
        if (strncmp($name, 'HTTP_', 5) === 0) 
        { 
            $name = str_replace(' ', '-', ucwords(strtolower(str_replace('_', ' ', substr($name, 5))))); 
            $headers[$name] = $value; 
        } else if ($name == "CONTENT_TYPE") { 
            $headers["Content-Type"] = $value; 
        } else if ($name == "CONTENT_LENGTH") { 
            $headers["Content-Length"] = $value; 
        } 
    } 
    return $headers; 
 }

can be used on any WEB server.