Zend - Validation

To validate an input, use Zend_Validate class and an implementation of the class that use it:

require_once "Zend/Validate.php";

require_once "Zend/Validate/StringLength.php";

$validator = new Zend_Validate_StringLength(5);

$input = "Coming Here";

if($validator->isValid($input)){

     // success code

}else{

     // error code

     echo current($validator->getMessages());

}

Zend - Validation