How can I allow only 2 dots after @ in email validation php using ereg

Question

I am trying to validate email in php using ereg, where I am not allowed to enter more than two dots after @ and it can't begin with any special character, how can I do it.

function chk($a)
{

$pattern = "^([A-Za-z0-9\.|-|_]{1,60})([@])";
$pattern .="([A-Za-z0-9\.|-|_]{1,60})(\.)([A-Za-z]{2,3})$";

  if (!@ereg($pattern, $a))
     return false;
  else
       return true;
}

can you try this `$pattern .="([A-Za-z0-9\.|-|_]{1,60})([\.{2}])([A-Za-z]{2,3})$";` — Pratik Soni, Jul 15 '15 at 19:12
Can you provide a sample input and why are you using ereg? `Warning This function has been DEPRECATED as of PHP 5.3.0. Relying on this feature is highly discouraged.` I think `preg_match` should work for you. — chris85, Jul 15 '15 at 19:17
[email protected] is valid [email protected] too is valid but, [email protected] is invalid. I am aware of it, but I need it for my understanding. — Hunterr, Jul 15 '15 at 19:21
It is perfectly valid to have email addresses at a subdomain, i.e. [email protected]. Therefore, your “only two dots after the @ sign” validation will flag false positives. If this is a lesson in using regular expressions, it’s a poor one. — Martin Bean, Jul 15 '15 at 19:23
Btw, any amount of dots are valid in email addresses. For training purpose ok, but don't exclude legit users from any service you plan to offer. Like `[email protected]` is super valid. — Daniel W., Jul 15 '15 at 19:23
That's not true in general. Employees at many UK schools have addresses of the form `[email protected]`, for instance. — , Jul 15 '15 at 19:25
Thanks to all for the suggestions, probably informations. It may be valid to have any number of dots after the @ sign, but for self understanding, what shall be the proper regex to accept only two dots that was the basic question. — Hunterr, Jul 15 '15 at 19:30

score 3 · Answer 1 · answered Jul 15 '15 at 19:15

3

Please don't roll your own email validation.

if(filter_var($email, FILTER_VALIDATE_EMAIL) === true){
    return true;
} else {
    return false;
}

answered Jul 15 '15 at 19:15

cmorrissey

8,493
2
23
27

I am supposed to use ereg and explode no any inbuilt functions. – Hunterr Jul 15 '15 at 19:17
not exactly, need to do without inbuilt functions for understanding ergs better way. – Hunterr Jul 15 '15 at 19:19
@hunter You can use inbuilt as well. – Pratik Soni Jul 15 '15 at 19:22
Added an up-vote after this was down-voted (presumably by the OP as they took exception to it). This is a perfectly valid answer and the solution I would have recommended myself. – Martin Bean Jul 15 '15 at 19:24
@Martin, agree its valid, but I need to do it using ereg. – Hunterr Jul 15 '15 at 19:26

score 2 · Answer 2 · answered Jul 15 '15 at 19:21

2

preg_match("/^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/",'[email protected].');

answered Jul 15 '15 at 19:21

Pratik Soni

2,498
16
26

This will possibly match every valid email. – Pratik Soni Jul 15 '15 at 19:21
Thanks @Pratik, I need to try it using ereg. :) – Hunterr Jul 15 '15 at 19:24
use `preg_match` instead. ereg is `DEPRECATED`. – Pratik Soni Jul 15 '15 at 19:25

score 0 · Answer 3 · answered Apr 30 '21 at 17:13

function custom_email_confirmation_validation_filter( $your_email ) {
   if(!preg_match("/^([a-z0-9\+_\-]+)(\.[a-z0-9\+_\-]+)*@([a-z0-9\-]+\.)+[a-z]{2,6}$/ix", $your_email )){ 
        return 'invalid';
    }
    
  if( substr_count($your_email, '.') > 3){
    return 'invalid 1';
  }
  
  return 'valid';
}

echo custom_email_confirmation_validation_filter('[email protected]');

How can I allow only 2 dots after @ in email validation php using ereg

3 Answers3