PHP Alphanumeric Regular Expression

Question

I am new to PHP, and very new to Regular Expressions. I am currently trying to write a Regular Expression that makes sure the characters are all Alpha Numeric, and that accepts other characters a well. I would like to accept áéíñóúüÁÉÍÑÓÚÜ and @.+-. To accept all alphanumeric characters, and the symbols @.+-. I use the expression:

if (!preg_match("!^[\[email protected]]*$!")

Also, before I continue I would like to add. These are values being grabbed from a form input, and they should all be one word phrases (as in no spaces). Ok now lets continue! :D Now I want to grab the characters áéíñóúüÁÉÍÑÓÚÜ as well. When I use the expression:

if (!preg_match("/[\wáéíñóúüÁÉÍÑÓÚÜ@.\+-].*/")

It does not seem to work, could anyone please help? If you are confused, or it is worded bad just ask and I will rewrite it :)

UPDATE

My expression:

if (!preg_match("!^[\[email protected]]*$!")

does work, it is the other one that is not working. Thank You! :)

UPDATE 2

Now when I try the expression:

if (!preg_match("~^[\p{L}\p{N}@+._-]+$~", $email)) {

with the input of michael.jonesáéí@gmail.com it raises a error. There error it raises is "Email contains restricted characters." because I made it say that. Here is the specific code I am using:

<?php
if (!preg_match("~^[\p{L}\p{N}@+._-]+$~", $email)) {
?>
<div id="allinputboxerror" class="col-xs-12"> Email contains restricted characters.</div>
<?php } ?>  
                                                }

and here is all of the code I am using:

<?php
                                if ($_POST) {
                                    $emailtest1 = False;
                                    $emailtest2 = False;
                                    $emailtest3 = False;
                                    $emailtest4 = False;
                                    $emailtest5 = False;

                                    // Test #1 - Makes sure there is a input

                                    if(empty($_POST['email'])) {
?>
                                        <div id="allinputboxerror" class="col-xs-12"> Please enter your email. </div>
<?php
                                    }

                                    else {
                                        $emailtest1 = True;

                                        // Test #2 - Makes sure it does not already exist

                                        $usernamequery = "SELECT 1 FROM users WHERE email = :email";

                                        $usernameparams = array(':email' => $_POST['email']);

                                        try{
                                            $emailstmt = $connection->prepare($usernamequery);
                                            $emailresult = $emailstmt->execute($usernameparams);
                                        }

                                        catch(PDOException $ex){
                                            echo ("Failed to run query: " . $ex->getMessage());
                                        }

                                        $emailcolumns = $emailstmt->fetch();

                                        if($emailcolumns){
?>
                                            <div id="allinputboxerror" class="col-xs-12"> This email already exists. </div>
<?php
                                        }

                                        else {
                                            $emailtest2 = True;

                                            // Test #3 - Makes sure it fits the length requirements

                                            if(strlen($email) < 5 ) {
?>
                                                <div id="allinputboxerror" class="col-xs-12"> Email is to short. </div>
<?php
                                            }

                                            elseif(strlen($email) > 75 ) {
?>
                                                <div id="allinputboxerror" class="col-xs-12"> Email is to long. </div>
<?php
                                            }

                                            else {
                                                $emailtest3 = True;

                                                // Test #4 - Makes sure it does not have any restricted characters

                                                if (!preg_match("~^[\p{L}\p{N}@+._-]+$~", $email)) {
?>
                                                    <div id="allinputboxerror" class="col-xs-12"> Email contains restricted characters. </div>
<?php       
                                                }

                                                else {
                                                    $emailtest4 = True;

                                                    // Test #5 - Makes sure the email is valid

                                                    if (!filter_var($_POST['email'], FILTER_VALIDATE_EMAIL)) {
?>
                                                        <div id="allinputboxerror" class="col-xs-12"> Not a valid email. </div>
<?php       
                                                    }

                                                    else {
                                                        $emailtest5 = True;

                                                        // Final Check

                                                        if (($emailtest1 = True) and ($emailtest2 = True) and ($emailtest3 = True) and ($emailtest4 = True) and ($emailtest5 = True)) {
                                                            // Email is valid! :D
                                                        }

                                                        else {
?>
                                                            <div id="allinputboxerror" class="col-xs-12"> There is a error. </div>
<?php
                                                        }
                                                    }
                                                }
                                            }
                                        }
                                    }
                                }   
?>

Avinash Raj · Accepted Answer · 2014-12-30 19:11:17Z

2

Regex to accept all alphanumeric characters, and the symbols @.+-.

^[\p{L}\p{N}@+.-]+$

Your regex ^[\[email protected]]*$ won't match the accented characters. That is \w would match only the English alphabets, digits 0-9 plus the underscore symbol.

\p{L} matches any kind of letter from any language
\p{N} matches any kind of numeric character in any script.
+ after the char class would repeat the previous token one or more times. I suggest you to use + instead of * because * repeats the previous token zero or more times. So it matches empty strings also.

DEMO

Update:

You ust need to include the unicode modifier u, so that it would make \p{L} to match accented characters.

if (!preg_match("~^[\p{L}\p{N}@+._-]+$~u", $email)) {

edited Dec 30, 2014 at 19:11

answered Dec 30, 2014 at 18:19

Avinash Raj

175k32 gold badges247 silver badges289 bronze badges

Sign up to request clarification or add additional context in comments.

13 Comments

ruakh Over a year ago

I think this answer would be better if you also explained where the OP went wrong.

Avinash Raj Over a year ago

@ruakh i think i explained.

ruakh Over a year ago

@Tom: I think you've misparsed the sentence you quote. Avinash Raj means "\w will only match certain kinds of letters from certain languages".

Tom Over a year ago

@ruakh He didn't wrote that it matches some/certain letter. He wrote that it won't match any letter.

Avinash Raj Over a year ago

@ruakh you're correct. I need to improve my writting skills.

|

Collectives™ on Stack Overflow

PHP Alphanumeric Regular Expression

1 Answer 1

13 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

13 Comments

Your Answer

Sign up or log in

Post as a guest

Related