Regular Expressions

Looking for a definitive email regular expression?

Here you have a regular expression to validate an email with no delimiters warnings

For this array test there are only three valid email adresses

$data=array(
"NotAnEmail",
"@NotAnEmail",
"test\blah@example.com",
"\"test\\\rblah\"@example.com",
"\"test\rblah\"@example.com",
"customer/department@example.com",
"&A12345@example.com",
"!def!xyz%abc@example.com",
"_Yosemite.Sam@example.com",
"~@example.com",
".wooly@example.com",
"wo..oly@example.com",
"pootietang.@example.com",
".@example.com",
"Austin@Powers\"@example.com",
"p.c.i.@example.fr",
"p.c.i@example.fr",
"ImaFool.@example.com",
"Ima.Fool@example.com",
"ima.fool@example.com",
"Ima Fool@example.com"
);


// Regular expression pattern with no warnings

$pattern='/^[a-z0-9]+([_\\.-][a-z0-9]+)*@([a-z0-9]+([\.-][a-z0-9]+)*)+\\.[a-z]{2,}$/i';


foreach($data as $email)
{
    if(!preg_match($pattern,$email))
    {
        echo "\n ".$email." => is NOT valid";
    }
}

This will print out 18 non valid email addresses. The validation is only for the format, chacking that the email format is valid only and not if the address exists