PHP实现获取ip地址的5种方法，以及插入用户登录日志操作示例

<?php  //方法1：
$ip = $_SERVER["REMOTE_ADDR"];
echo $ip;
//方法2：
$ip = ($_SERVER["HTTP_VIA"]) ? $_SERVER["HTTP_X_FORWARDED_FOR"] : $_SERVER["REMOTE_ADDR"];
$ip = ($ip) ? $ip : $_SERVER["REMOTE_ADDR"];
echo $ip;
//方法3：
function getRealIp()
{
  $ip=false;
  if(!empty($_SERVER["HTTP_CLIENT_IP"])){
    $ip = $_SERVER["HTTP_CLIENT_IP"];
  }
  if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
    $ips = explode (", ", $_SERVER['HTTP_X_FORWARDED_FOR']);
    if ($ip) { array_unshift($ips, $ip); $ip = FALSE; }
    for ($i = 0; $i < count($ips); $i++) {
      if (!eregi ("^(10│172.16│192.168).", $ips[$i])) {
        $ip = $ips[$i];
        break;
      }
    }
  }
  return ($ip ? $ip : $_SERVER['REMOTE_ADDR']);
}
echo getRealIp();
//方法4：
if ($HTTP_SERVER_VARS["HTTP_X_FORWARDED_FOR"])
{
  $ip = $HTTP_SERVER_VARS["HTTP_X_FORWARDED_FOR"];
}
elseif ($HTTP_SERVER_VARS["HTTP_CLIENT_IP"])
{
  $ip = $HTTP_SERVER_VARS["HTTP_CLIENT_IP"];
}
elseif ($HTTP_SERVER_VARS["REMOTE_ADDR"])
{
  $ip = $HTTP_SERVER_VARS["REMOTE_ADDR"];
}
elseif (getenv("HTTP_X_FORWARDED_FOR"))
{
  $ip = getenv("HTTP_X_FORWARDED_FOR");
}
elseif (getenv("HTTP_CLIENT_IP"))
{
  $ip = getenv("HTTP_CLIENT_IP");
}
elseif (getenv("REMOTE_ADDR"))
{
  $ip = getenv("REMOTE_ADDR");
}
else
{
  $ip = "Unknown";
}
echo $ip ;
//方法5：
if(getenv('HTTP_CLIENT_IP')) {
  $onlineip = getenv('HTTP_CLIENT_IP');
} elseif(getenv('HTTP_X_FORWARDED_FOR')) {
  $onlineip = getenv('HTTP_X_FORWARDED_FOR');
} elseif(getenv('REMOTE_ADDR')) {
  $onlineip = getenv('REMOTE_ADDR');
} else {
  $onlineip = $HTTP_SERVER_VARS['REMOTE_ADDR'];
}
echo $onlineip;

//增加用户登录日志
$ip = ($_SERVER["HTTP_VIA"]) ? $_SERVER["HTTP_X_FORWARDED_FOR"] : $_SERVER["REMOTE_ADDR"];
$ip = ($ip) ? $ip : $_SERVER["REMOTE_ADDR"];
$this->usermodel->addUserlog($userid,$nickname,$ip);
function addUserlog($userid,$nickname,$ip) {
    try {
      $now = date("Y-m-d H-i-s",time());
      $data=array(
        'userid'=>$userid,
        'nickname'=>$nickname,
        'ip'=>$ip,
        'logintime'=>$now
      );
      $insert_query = $this->db->insert_string('user_log', $data);
      $this->db->query($insert_query);
      return 0;
    } catch ( Exception $e ) {
      return -1;
    }
}

CREATE TABLE `user_log` (
 `id` bigint(20) NOT NULL AUTO_INCREMENT,
 `userid` bigint(20) NOT NULL,
 `nickname` varchar(50) NOT NULL,
 `ip` varchar(50) NOT NULL,
 `logintime` datetime NOT NULL,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8