PHP erigi : Depreciated (e-mail validation)

Question

Since erigi() is deprecated in PHP 5 and I am in a need to validate an e-mail id , so which function should be used...? further please give the format for e-mail validation such as:

<?php
function checkEmail($email) 
{
   if(eregi("^[a-zA-Z0-9_]+@[a-zA-Z0-9\-]+\.[a-zA-Z0-9\-\.]+$]", $email)) 
   {
      return FALSE;
   }

   list($Username, $Domain) = split("@",$email);

   if(getmxrr($Domain, $MXHost)) 
   {
      return TRUE;
   }
   else 
   {
      if(fsockopen($Domain, 25, $errno, $errstr, 30)) 
      {
         return TRUE; 
      }
      else 
      {
         return FALSE; 
      }
   }
}
?>

Answer 1

For php 5.2: http://php.net/manual/en/function.filter-var.php

$result = filter_var($email , FILTER_VALIDATE_EMAIL);

Or http://pl.php.net/manual/en/function.preg-match.php for any regular expression.

Answer 2

Use the filter_var PHP function instead:

if (filter_var($email, FILTER_VALIDATE_EMAIL)) {

}

Or, even better yet, use a RFC-compliant email address validator. As no amount of regex will encompass all the valid emails that are possible.

Answer 3

En example with with filter extension.

<?php
function is_valid_email($email)
{
    return filter_var($email, FILTER_VALIDATE_EMAIL) !== false;
}

var_dump(is_valid_email('[email protected]'));
var_dump(is_valid_email('foobar'));
var_dump(is_valid_email('[email protected]'));

[~]> php x.php 
bool(true)
bool(false)
bool(true)

This you can then combine with further validation that you already have.