How to implement PHP to allow only specified IP access

This article mainly explains "PHP how to achieve only specified IP access", the content of the article is simple and clear, easy to learn and understand, the following please follow the editor's ideas slowly in depth, together to study and learn "PHP how to achieve only specified IP access" bar!

The core function code is as follows:

/ * detect whether the accessed ip is the specified allowed ip * Enter description here. * / function check_ip () {$ALLOWED_IP=array ('192.168.2.', $IP); $IP=getIP (); $check_ip_arr= explode ('., $IP) / / the ip to be detected is split into an array # restrict IP if (! in_array ($IP,$ALLOWED_IP)) {foreach ($ALLOWED_IP as $val) {if (strpos ($val,'*')! = = false) {/ / find a * sign substitute $arr=array (); / / $arr=explode ('.', $val) $bl=true;// is used to record whether there is a matching for in the loop test.