PHP/String/Email Format

A regular expression for e-mail string checking

 
<?php 
$email = "l@b.ca"; 
echo preg_match("/^([a-zA-Z0-9])+([.a-zA-Z0-9_-])*@([a-zA-Z0-9_-])+.(.[a-zA-Z0-9_-]+)+[a-zA-Z0-9_-]$/",$email); //Would return 1 (true). 
echo "<br />"; 
$bademail = "l.ca"; 
echo preg_match("/^([a-zA-Z0-9])+([.a-zA-Z0-9_-])*@([a-zA-Z0-9_-])+.(.[a-zA-Z0-9_-]+)+[a-zA-Z0-9_-]$/",$bademail); //Would return 0 (false). 
?>

Use regular to check email address

 
<?php
  $regex = "/^[\w\d!#$%&"*+-\/=?^"{|}~]+(\.[\w\d!#$%&"*+-\/=?^"{|}~]+)*@([a-z\d][-a-z\d]*[a-z\d]\.)+[a-z][-a-z\d]*[a-z]$/";
  $values = array(
    "user@example.ru",       // Valid
    "u2@example.ru",     // Valid
    );
  foreach ($values as $value) {
    if (preg_match($regex, $value)) {
      printf("Found valid address:   %s\n", $value);
    } else {
      printf("INVALID address:   %s\n", $value);
    }
  }
?>

Validate email

 
<?php
   function validate_email($email) { 
      $regexp = "^([_a-z0-9-]+)(\.[_a-z0-9-]+)*@([a-z0-9-]+)(\.[a-z0-9-]+)*(\.[a-z]{2,6})$";
      if (eregi($regexp, $email)) return 1;
         else return 0;
   }
   if (isset($_POST["submit"])){
      echo "Hi ".$_POST["name"]."!<br />";
      if (validate_email($_POST["email"]))
         echo "The address ".$_POST["email"]." is valid!";
      else
         echo "The address <strong>".$_POST["email"]."</strong> is invalid!";
   }
?>
<form action="index.php" method="post">
   Name:<input type="text" name="name" value="" />
   Email Address:<input type="text" name="email" value="" />
   <input type="submit" name = "submit" value="Go!" />
</form>