增加curl_setopt($curl, CURLOPT_HTTPHEADER, $http_headers) 设置，即可解决

function httpRead($url)
{

    $http_headers = array( 
        'User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:40.0)' . 'Gecko/20100101 Firefox/40.0', 
        'Accept: */*', 
        'X-Requested-With: XMLHttpRequest', 
        'Referer: http://www.barneys.com', # IMPORTANT 
        'Accept-Language: pt-BR,en-US;q=0.7,en;q=0.3', 
        );
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_HTTPHEADER, $http_headers);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($curl, CURLOPT_TIMEOUT, 500);
    curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
    curl_setopt($curl, CURLOPT_URL, $url);

    $res = curl_exec($curl);
    curl_close($curl); 
    return $res;
}