Explication détaillée de l'exemple de code de programme de liste noire IP de jugement PHP

/*
* ip地址黑名单、白名单
* 判断访客地址的ip是否在ip.txt中，支持c类ip
* By xhat
*/
$ip = $_SERVER['REMOTE_ADDR'];
$ipArray = preg_replace("#rn?|n#","",file('ip.txt'));
foreach ($ipArray as $ipTest) {
if (substr_count($ip, $ipTest) != "0") {
echo "ok"; //执行相关命令
die();
}
}
?>

<?php 
class block_ip { 
var $Block_ip = array("192.168.1.1","210.10.2.1-20","222.34.4.*"); 
function construct(){ 
} 
function destruct(){ 
} 
private function makePregIP($str){ 
if (strstr($str,"-")) { 
$aIP = explode(".",$str); 
foreach ($aIP as $k=>$v) { 
if (!strstr($v,"-")) { 
$preg_limit .= makePregIP($v); 
} else{ 
$aipNum = explode("-",$v); 
for($i=$aipNum[0];$i<=$aipNum[1];$i++){ 
$preg .=$preg?"|".$i:"[".$i; 
} 
$preg_limit .=strrpos($preg_limit,".",1)==(strlen($preg_limit)-1)?$preg."]":".".$preg."]"; 
} 
} 
}else{ 
$preg_limit .= $str."."; 
} 
return $preg_limit; 
} 
private function getAllBlockIP(){ 
if ($this->Block_ip) { 
foreach ($this->Block_ip as $k=>$v) { 
$ipaddres = $this->makePregIP($v->start_ip); 
$ip = str_ireplace(".",".",$ipaddres); 
$ip = str_replace("*","[0-9]{1,3}",$ip); 
$ipaddres = "/".$ip."/"; 
$ip_list[] = $ipaddres; 
} 
} 
return $ip_list; 
} 
public function checkIP() { 
$iptable = $this->getAllBlockIP(); 
$IsJoined = true; 
//取得用户ip 
$Ip = $this->get_client_ip(); 
$Ip = trim($Ip); 
//剔除黑名单中的IP区段 
if ($iptable) { 
foreach($iptable as $value) { 
if (preg_match("{$value}",$Ip)) { 
$IsJoined = false; 
break; 
} 
} 
} 
// 如果在ip黑名单中就执行如下操作 
if( !$IsJoined ){ 
echo "IP Error"; 
exit; 
} 
} 
private function get_client_ip(){ 
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[&#39;REMOTE_ADDR&#39;]) && $_SERVER[&#39;REMOTE_ADDR&#39;] && strcasecmp($_SERVER[&#39;REMOTE_ADDR&#39;], "unknown")) 
$ip = $_SERVER[&#39;REMOTE_ADDR&#39;]; 
else 
$ip = "unknown"; 
return($ip); 
} 
} 
?>

$oBlock_ip = new block_ip(); 
$oBlock_ip->checkIP();