在php中验证url

I have the following seems simple code in php; but the ptoblem is that it shows all valid links as "not valid"; any help appreciated:

<?php
   $m = "urllist.txt";
   $n = fopen($m, "r");
   while (!feof($n)) {
      $l = fgets($n);
      if (filter_var($l, FILTER_VALIDATE_URL) === FALSE) {
          echo "NOT VALID - $l<br>";
      } else {
          echo "VALID - $l<br>";
      }
   }
   fclose($n);
?>

The string returned by fgets() contains a trailing newline character that needs to be trimmed before you can validate it. Try out following code, I hope this will help you:

<?php
  $m = "urllist.txt";
  $n = fopen($m, "r");
  while (!feof($n)) {
    $l = fgets($n);
    if(filter_var(trim($l), FILTER_VALIDATE_URL)) {
      echo "VALID - $l<br>";
    } else {
      echo "NOT VALID - $l<br>";
    }      
  }
  fclose($n);
?>

I have tried with following urls:

http://stackoverflow.com/
https://www.google.co.in/
https://www.google.co.in/?gfe_rd=cr&ei=bf4HVLOmF8XFoAOg_4HoCg&gws_rd=ssl
www.google.com
http://www.example.com
example.php?name=Peter&age=37

and get following result:

VALID - http://stackoverflow.com/ 
VALID - https://www.google.co.in/ 
VALID - https://www.google.co.in/?gfe_rd=cr&ei=bf4HVLOmF8XFoAOg_4HoCg&gws_rd=ssl 
NOT VALID - www.google.com 
VALID - http://www.example.com 
NOT VALID - example.php?name=Peter&age=37 

maybe you have some symbols at end of each line ' '

I think you can just use trim function before validate the $l like this:

filter_var(trim($l), FILTER_VALIDATE_URL) === TRUE

maybe this will help you.

Try this code. It must be helpful. I have tested it and its working.

<?php
    $m = "urllist.txt";
    $n = fopen($m, "r");
    while (!feof($n)) {
        $l = fgets($n);
        if(filter_var(trim($l), FILTER_VALIDATE_URL)) {
            echo "URL is not valid";
        }
        else{
            echo "URL is valid";
        }
    }
    fclose($n);
?>

Here is the DEMO

Please try with the different filters available to see where it fails:

• FILTER_FLAG_SCHEME_REQUIRED - Requires URL to be an RFC compliant URL (like http:// example)
• FILTER_FLAG_HOST_REQUIRED - Requires URL to include host name (like http:// www.example.com)
• FILTER_FLAG_PATH_REQUIRED - Requires URL to have a path after the domain name (like www. example.com/example1/test2/)
• FILTER_FLAG_QUERY_REQUIRED - Requires URL to have a query string (like "example.php?name=Peter&age=37")

(cc of http://www.w3schools.com/php/filter_validate_url.asp)

You can try the good old regex too:

if (!preg_match("/\b(?:(?:https?|ftp):\/\/|www\.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]/i",$url))