分类目录归档：PHP

PHP安全的获取ip 

    public static function getIpX(): ?string {
        [$ip] = self::getIp();
        return $ip;
    }

    public static function getIp(): array {
        $ip0 = $ip = $_SERVER['REMOTE_ADDR'] ?? null;
        if (in_array($ip, [
            '10.29.185.7', '127.0.0.1', '172.17.0.1', '172.31.242.237', # 可信IP列表
        ])) {
            $ip1 = $_SERVER['HTTP_X_FORWARDED_FOR'] ?? null;
            if ($ip1) {
                $ip0 = $ip1;
                $ip = explode(',', $ip1)[0];
            }
        }
        if (!$ip) {
            $ip = $_SERVER['REMOTE_ADDR'] ?? null;
        }
        return [$ip, $ip0];
    }

PHP简易排队限流实现 

$fp = fopen(sprintf("tmp/wk_exam_examination.%d.lock", $userid % 10), "w");
if (!flock($fp, LOCK_EX | LOCK_NB)) {
    ?>
  <style>
    #info {
      text-align: center;
      margin: 50px 0;
    }

    #info td {
      font-size: 36px;
      color: seagreen;
    }
  </style>
  <div id='info'></div>
  <script>
    let sec = 5000
    setTimeout(function () {
      window.location.reload()
    }, sec)
    setInterval(function () {
      sec -= 100
      if (sec >= 0) {
        let ok = sec / 1000
        document.getElementById('info').innerHTML = `<table style="margin: 0 auto;">
        <tr><td style='width: 50%; text-align: right;'>页面排队中...</td>
        <td style="width: 2em; text-align: center;">${ok}</td><td>秒后将重试！</td></tr></table>`;
      }
    }, 100)
  </script><?php
    die;
}