<?php
//获取客户端ip
$onlineip = '';
$cip = getenv ( 'HTTP_CLIENT_IP' ); //getenv()从环境中取字符串,获取环境变量的值,用户IP
$xip = getenv ( 'HTTP_X_FORWARDED_FOR' ); //浏览当前页面的用户计算机的网关
$rip = getenv ( 'REMOTE_ADDR' ); //用户浏览器所在机器的网址
$srip = $_SERVER ['REMOTE_ADDR']; //正在浏览当前页面用的IP地址
//strcasecmp二进制安全比较字符串(不区分大小写)
if ($cip && strcasecmp ( $cip, 'unknown' )) {
$onlineip = $cip;
} elseif ($xip && strcasecmp ( $xip, 'unknown' )) {
$onlineip = $xip;
} elseif ($rip && strcasecmp ( $xip, 'unknown' )) {
$onlineip = $rip;
} elseif ($srip && strcasecmp ( $srip, 'unknown' )) {
$onlineip = $srip;
}
preg_match ( '/[\d\.]{7,15}/', $onlineip, $match );
$onlineip = $match [0] ? $match [0] : 'unknown';
echo $onlineip;
?>