PHP获取客户端真实IP

//获取用户真实IP
function getIp() {
if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown"))
$ip = getenv("HTTP_CLIENT_IP");
else
if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown"))
$ip = getenv("HTTP_X_FORWARDED_FOR");
else
if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown"))
$ip = getenv("REMOTE_ADDR");
else
if (isset ($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown"))
$ip = $_SERVER['REMOTE_ADDR'];
else
$ip = "unknown";
return ($ip);
}

echo getIp();

/**
* 获取在线IP
* @return String
*/
function getOnlineIp($format=0) {
global $S_GLOBAL;
if(empty($S_GLOBAL['onlineip'])) {
if(getenv('HTTP_CLIENT_IP') && strcasecmp(getenv('HTTP_CLIENT_IP'), 'unknown')) {
$onlineip = getenv('HTTP_CLIENT_IP');
} elseif(getenv('HTTP_X_FORWARDED_FOR') && strcasecmp(getenv('HTTP_X_FORWARDED_FOR'), 'unknown')) {
$onlineip = getenv('HTTP_X_FORWARDED_FOR');
} elseif(getenv('REMOTE_ADDR') && strcasecmp(getenv('REMOTE_ADDR'), 'unknown')) {
$onlineip = getenv('REMOTE_ADDR');
} elseif(isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], 'unknown')) {
$onlineip = $_SERVER['REMOTE_ADDR'];
}
preg_match("/[\d\.]{7,15}/", $onlineip, $onlineipmatches);
$S_GLOBAL['onlineip'] = $onlineipmatches[0] ? $onlineipmatches[0] : 'unknown';
}

if($format) {
$ips = explode('.', $S_GLOBAL['onlineip']);
for($i=0;$i<3;$i++) {
$ips[$i] = intval($ips[$i]);
}
return sprintf('%03d%03d%03d', $ips[0], $ips[1], $ips[2]);
} else {
return $S_GLOBAL['onlineip'];
}
}

/**
* 获取客户端IP
* @return [string] [description]
*/
function getClientIp() {
$ip = NULL;
if (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
$arr = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
$pos = array_search('unknown',$arr);
if(false !== $pos) unset($arr[$pos]);
$ip = trim($arr[0]);
}elseif (isset($_SERVER['HTTP_CLIENT_IP'])) {
$ip = $_SERVER['HTTP_CLIENT_IP'];
}elseif (isset($_SERVER['REMOTE_ADDR'])) {
$ip = $_SERVER['REMOTE_ADDR'];
}
// IP地址合法验证
$ip = (false !== ip2long($ip)) ? $ip : '0.0.0.0';
return $ip;
}