validate

[mrneilrobinson]

hello ive been asked  what regex will validate an email address?

 

im not sure what this means

 

kind regards

 

neil

[abazoskib]

I use this:

 

function checkEmail($email) {
                // checks proper syntax
                $regexp = "^([_a-z0-9-]+)(\.[_a-z0-9-]+)*@([a-z0-9-]+)(\.[a-z0-9-]+)*(\.[a-z]{2,4})$";
                if(eregi($regexp, $email)){
                        if(checkdnsrr(array_pop(explode("@",$email)),"MX")){
                                return true; //EMAIL IS WELL FORMED AND EXISTS
                        }else{
                                return false; //EMAIL SERVER DOES NOT EXIST
                        }
                } else
                        return false; //EMAIL IS NOT WELL FORMED 
        }

[cags]

The actual specification for email addresses is quite complex. To be 100% accurate you would probably need a validation class rather than a simple regex pattern. Having said that some of the 'valid' e-mail addresses are that uncommon most people just don't care about them. The pattern I've been using is...

 

'/^[a-zA-Z0-9._-]+@[a-zA-Z0-9-]+\.[a-zA-Z.]{2,5}$/'

 

... I didn't write it I just found it on an online resource somewhere, I can't honestly remember where now. Just bare in mind there are many ways to skin a cat.

[premiso]

ive been asked

 

hmmm I think most teachers expect you to find the answer yourself and not have it spoon fed to you. =\

[salathe]

im not sure what this means

 

What exactly are you having trouble with? Do you understand what a "regex" is; what "validation" is; what an "email address" is?

 

 

[newbtophp]

You might find this useful:

 

http://www.regular-expressions.info/email.html