PHP 判断 Email 在 Gravatar 有没有自定义头像

<?php
function check_have_avatar($email){
    $md5 = md5(strtolower(trim($email)));
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, "http://www.gravatar.com/avatar/{$md5}");
    curl_setopt($ch, CURLOPT_HTTPHEADER, [
        'User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36'
    ]);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    $result = curl_exec($ch);
    curl_close($ch);

    if(md5($result) === 'd5fe5cbcc31cff5f8ac010db72eb000c'){
        return false;
    }

    return $result;
}

if(!check_have_avatar('ne@nowtime.cc')){
    echo '没有自定义头像';
}else{
    echo '有自定义头像';
}