PHP结合Redis来限制用户或者IP某个时间段内访问的次数

$redis = new Redis();
$redis->connect('127.0.0.1', 6379);

//获取客户端真实ip地址
function get_real_ip(){
static $realip;
if(isset($_SERVER)){
if(isset($_SERVER['HTTP_X_FORWARDED_FOR'])){
$realip=$_SERVER['HTTP_X_FORWARDED_FOR'];
}else if(isset($_SERVER['HTTP_CLIENT_IP'])){
$realip=$_SERVER['HTTP_CLIENT_IP'];
}else{
$realip=$_SERVER['REMOTE_ADDR'];
}
}else{
if(getenv('HTTP_X_FORWARDED_FOR')){
$realip=getenv('HTTP_X_FORWARDED_FOR');
}else if(getenv('HTTP_CLIENT_IP')){
$realip=getenv('HTTP_CLIENT_IP');
}else{
$realip=getenv('REMOTE_ADDR');
}
}
return $realip;
}

//这个key记录该ip的访问次数 也可改成用户id
$key = get_client_ip(); //该Key记录访问的次数，目前是以IP为例，也可以把用户id作为key，如userid_123456

//限制次数为3次。
$limit = 3;

$check = $redis->exists($key);
if($check){
$redis->incr($key);
$count = $redis->get($key);
if($count > 3){
exit('已经超出了限制次数');
}

}else{
$redis->incr($key);
//限制时间为60秒
$redis->expire($key,60);
}

$count = $redis->get($key);
echo '第 '.$count.' 次请求';

获取ip方法

function get_real_ip() {
    static $realip = NULL;
    if ($realip !== NULL) {
        return $realip;
    }
    if (isset($_SERVER)) {
        if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
            $arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
            /* 取X-Forwarded-For中第一个非unknown的有效IP字符串 */
            foreach ($arr AS $ip) {
                $ip = trim($ip);
                if ($ip != 'unknown') {
                    $realip = $ip;
                    break;
                }
            }
        } elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {
            $realip = $_SERVER['HTTP_CLIENT_IP'];
        } else {
            if (isset($_SERVER['REMOTE_ADDR'])) {
                $realip = $_SERVER['REMOTE_ADDR'];
            } else {
                $realip = '0.0.0.0';
            }
        }
    } else {
        if (getenv('HTTP_X_FORWARDED_FOR')) {
            $realip = getenv('HTTP_X_FORWARDED_FOR');
        } elseif (getenv('HTTP_CLIENT_IP')) {
            $realip = getenv('HTTP_CLIENT_IP');
        } else {
            $realip = getenv('REMOTE_ADDR');
        }
    }
    // 使用正则验证IP地址的有效性，防止伪造IP地址进行SQL注入攻击
    preg_match("/[d.]{7,15}/", $realip, $onlineip);
    $realip = !empty($onlineip[0]) ? $onlineip[0] : '0.0.0.0';
    return $realip;
}