PHP function to verify that the URL is legitimate

There are two kinds of authentication URL is the use of regular expressions to verify that the URL is not the appropriate URL rules, the other is to use the function to access the specified URL to see whether the normal access, if the normal access to natural is the legitimate URL address.

Example 1

The code is as follows

<?php function Isvalidurl ($url) { $patern = '/^http[s]?:\/\/'. ' ([0-9]{1,3}\.] {3} [0-9] {1,3} '. URL-199.194.52.184 in IP form '|'. IP and domain (domain name) allowed ' ([0-9a-z_!~*\ ' ()-]+\.) *'. Level three domain validation-www. ' ([0-9a-z][0-9a-z-]{0,61}]? [0-9a-z]\.] Second-level domain validation ' [a-z]{2,6}] '. Top-level domain authentication. com or. Museum ' (: [0-9]{1,4}]? '. Port-: 80 ' ((\/\?) | '. If you have a file that verifies the file part ' (\/[0-9a-za-z_!~\*\ ' (\) \.; \?:@&=\+\$,%#-\/]*)? $/'; if (!preg_match ($patern, $url)) { Die (' The URL format you entered has a problem, please check! '); } }

Example 2

The above example just verifies that the URL is not normal and does not mean that it can be accessed, and we can use the method such as the Curl function

The code is as follows
$url = "Http://www.45it.net"; $curl = Curl_init ($url); curl_setopt ($curl, Curlopt_nobody, true); $result = curl_exec ($curl); if ($result!== false) { $statusCode = Curl_getinfo ($curl, Curlinfo_http_code); if ($statusCode = = 404) { echo "URL not Exists" } Else { echo "URL Exists"; } } Else { echo "URL not Exists"; }

In addition to this function can also use PHP's many functions such as file, file_get_contents (), fopen function to detect.