Where could I find a script that validates an email address when users register?

[Smudly]

I'm trying to create a professional script that validates that an email typed in a text field by the user when they are registering, is an actual email address. So, if the email address is missing the @ sign or doesn't meet the typical parameters that an email should have, it will not pass and the user will have to type in a valid email address. This is pretty advanced for me. Any scripts you guys use that you would like to share? Or, where could I find a script that does something like this?

[harristweed]

	if ($email <> "" and !ereg("^[^@ ]+@[^@ ]+\.[^@ \.]+$", "$email"))
{
echo"Not ok";
}else{
echo"Yippee";
}

[Smudly]

Hey thanks for the reply. I'm having some troubles with my email validator however. When I hit submit, I keep getting the error "Enter a Valid Email", even if the email address is valid. There is something wrong with my structure but I can't figure it out. Here is the code I'm working with. The area that is having trouble is:

 

    //////////// Email Validation ////////////
function validEmail($email)
{
   $isValid = true;
   $atIndex = strrpos($email, "@");
   if (is_bool($atIndex) && !$atIndex)
   {
      $isValid = false;
   }
   else
   {
      $domain = substr($email, $atIndex+1);
      $local = substr($email, 0, $atIndex);
      $localLen = strlen($local);
      $domainLen = strlen($domain);
      if ($localLen < 1 || $localLen > 64)
      {
         // local part length exceeded
         $isValid = false;
      }
      else if ($domainLen < 1 || $domainLen > 255)
      {
         // domain part length exceeded
         $isValid = false;
      }
      else if ($local[0] == '.' || $local[$localLen-1] == '.')
      {
         // local part starts or ends with '.'
         $isValid = false;
      }
      else if (preg_match('/\\.\\./', $local))
      {
         // local part has two consecutive dots
         $isValid = false;
      }
      else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain))
      {
         // character not valid in domain part
         $isValid = false;
      }
      else if (preg_match('/\\.\\./', $domain))
      {
         // domain part has two consecutive dots
         $isValid = false;
      }
      else if
(!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/',
                 str_replace("\\\\","",$local)))
      {
         // character not valid in local part unless
         // local part is quoted
         if (!preg_match('/^"(\\\\"|[^"])+"$/',
             str_replace("\\\\","",$local)))
         {
            $isValid = false;
         }
      }
      if ($isValid && !(checkdnsrr($domain,"MX") || checkdnsrr($domain,"A")))
      {
         // domain not found in DNS
         $isValid = false;
      }
   }
   return $isValid;
}

        if (validEmail($email)==false){
        $proerror = "Enter a Valid Email";
    }
    else{
    //////////// End Email Validation /////////
   
    $update = "UPDATE `users` SET `fname`='$fnamenew', `lname`='$lnamenew', `email`='$emailnew' WHERE `username`='$username'";
    mysql_query($update);
    $success = "Success!";
    }

 

And here is my entire code:

 

<?php
session_start();
if (isset($_SESSION['username'])){

include('inc/connect.php');



$username = isset($_SESSION['username']) ? $_SESSION['username'] : '';

$edit = (isset($_POST['edit']));
$passchange = (isset($_POST['passchange']));

if (!empty($username))
{
    //if user is logged in

    $sql = mysql_query("SELECT * FROM `users` WHERE `username`='$username'");
    $row = mysql_fetch_assoc($sql);

    $dbfname = $row['fname'];
    $dblname = $row['lname'];
    $dbemail = $row['email'];
    $dbpassword = $row['password'];
    $passcapture = $_POST['password'];
    $password = md5($passcapture);
   
    $error = "";
    $proerror = "";
   
    if ($edit)
    {
   
        $fnamenew = mysql_real_escape_string(strtolower(strip_tags($_POST['fname'])));
        $lnamenew = mysql_real_escape_string(strtolower(strip_tags($_POST['lname'])));
        $emailnew = mysql_real_escape_string(strip_tags($_POST['email']));
       

       
   
    //////////// Email Validation ////////////
function validEmail($email)
{
   $isValid = true;
   $atIndex = strrpos($email, "@");
   if (is_bool($atIndex) && !$atIndex)
   {
      $isValid = false;
   }
   else
   {
      $domain = substr($email, $atIndex+1);
      $local = substr($email, 0, $atIndex);
      $localLen = strlen($local);
      $domainLen = strlen($domain);
      if ($localLen < 1 || $localLen > 64)
      {
         // local part length exceeded
         $isValid = false;
      }
      else if ($domainLen < 1 || $domainLen > 255)
      {
         // domain part length exceeded
         $isValid = false;
      }
      else if ($local[0] == '.' || $local[$localLen-1] == '.')
      {
         // local part starts or ends with '.'
         $isValid = false;
      }
      else if (preg_match('/\\.\\./', $local))
      {
         // local part has two consecutive dots
         $isValid = false;
      }
      else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain))
      {
         // character not valid in domain part
         $isValid = false;
      }
      else if (preg_match('/\\.\\./', $domain))
      {
         // domain part has two consecutive dots
         $isValid = false;
      }
      else if
(!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/',
                 str_replace("\\\\","",$local)))
      {
         // character not valid in local part unless
         // local part is quoted
         if (!preg_match('/^"(\\\\"|[^"])+"$/',
             str_replace("\\\\","",$local)))
         {
            $isValid = false;
         }
      }
      if ($isValid && !(checkdnsrr($domain,"MX") || checkdnsrr($domain,"A")))
      {
         // domain not found in DNS
         $isValid = false;
      }
   }
   return $isValid;
}

        if (validEmail($email)==false){
        $proerror = "Enter a Valid Email";
    }
    else{
    //////////// End Email Validation /////////
   
    $update = "UPDATE `users` SET `fname`='$fnamenew', `lname`='$lnamenew', `email`='$emailnew' WHERE `username`='$username'";
    mysql_query($update);
    $success = "Success!";
    }

    $dbfname = $fnamenew;
    $dblname = $lnamenew;
    $dbemail = $emailnew;
   
   
   
   
    }
   
    // Change Password
    if ($passchange)
    {
            if($password){
           
                if($password==$dbpassword){
               
                    $passwordnew = $_POST['passwordnew'];
                    $passwordconf = $_POST['passwordconf'];
                   
                    if (isset($passwordnew) && !empty($passwordnew)){
                   
                        if (isset($passwordconf) && !empty($passwordconf)){
                            if (strlen($passwordnew)>=6 && strlen($passwordconf)>=6){
                           
                                if ($passwordnew==$passwordconf){
                                   
                                    $passwordnew = md5($passwordnew);
                                   
                                $passupdate = "UPDATE `users` SET `password`='$passwordnew' WHERE `username`='$username'";
                                mysql_query($passupdate);
                               
                                $passsuccess = "Success!";
                               
                            }
                            else{
                                $error = "Your new password does not match!";
                            }
                            }
                            else{
                                $error = "Your new password must contain at least 6 characters!";
                            }
                        }
                        else{
                            $error = "Please type in your Confirmed Password!";
                        }
                     
                    }
                    else{
                        $error = "Please type in your New Password!";
                    }
               
                }
                else{
                    $error = "Invalid Password";
                }
       
       
       
            }
            else{
                $error = "Please type in your Password!";
            }
   
   
   
    }
   
}
}
else{
    header("Location: index.php");
}
?>

<html>
<head>
<title>Profile</title>


<script type="text/javascript" language="javascript">
function inputLimiter(e,allow) {
var AllowableCharacters = '';

if (allow == 'UserNameChar'){AllowableCharacters='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';}
if (allow == 'UsernameChar'){AllowableCharacters='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890';}

var k;

k=document.all?parseInt(e.keyCode): parseInt(e.which);

if (k!=13 && k!=8 && k!=0){

if ((e.ctrlKey==false) && (e.altKey==false)) {

return (AllowableCharacters.indexOf(String.fromCharCode(k))!=-1);

} else {

return true;

}

} else {

return true;

}

}

</script>
<style>
#container{
    width: 275px;
    margin-left: auto;
    margin-right: auto;
}
#profile{
    width: 222px;
    text-align: right;
    margin-left: auto;
    margin-right: auto;
   
}
#changepassword{
    width: 268px;
    text-align: right;
    margin-left: auto;
    margin-right: auto;
   
}
#centerpro{
    width: 60px;
    margin-left: auto;
    margin-right: auto;
}
#centerpas{
    width: 120px;
    margin-left: auto;
    margin-right: auto;
}
#center{
    width: 150px;
    margin-left: auto;
    margin-right: auto;
    text-align: center;
}
</style>
</head>
<body>
<div id="container">
<div id="profile">
    <h3 align="center">Profile</h3>
<form action="profile.php" method="POST">
    Username: <input type="text" value="<?php echo ucfirst($username); ?>" readonly="readonly"><br />
    First Name: <input type="text" maxlength="25" id="UserNameChar" onkeypress="return inputLimiter(event,'UserNameChar')" name="fname" value="<?php echo ucfirst($dbfname); ?>"><br />
    Last Name: <input type="text" maxlength="25" id="UserNameChar" onkeypress="return inputLimiter(event,'UserNameChar')" name="lname" value="<?php echo ucfirst($dblname); ?>"><br />
    Email: <input type="text" maxlength="64" name="email" value="<?php echo ucfirst($dbemail); ?>"><br />
    <div id="centerpro"><input type="submit" name="edit" value="Submit"></div>
    <div id="center"><?php echo $success, $proerror; ?></div>
</div>   
    <br />
    <br />
<div id="changepassword">
    <h3 align="center">Change Password</h3>
    Password: <input type="password" maxlength="25" name="password"><br /><br />
    New Password: <input type="password" maxlength="25" name="passwordnew"><br />
    Confirm Password: <input type="password" maxlength="25" name="passwordconf"><br />
    <div id="centerpas"><input type="submit" name="passchange" value="Change Password"></div>
    <div id="center"><?php echo $passsuccess, $error; ?></div>
</form>
</div>
</div>
</body>
</html>

 

[AbraCadaver]

Wow, just saw this EXACT question and code on another forum:

 

filter_var($email, FILTER_VALIDATE_EMAIL);