Zend_Validate_Regex - allow only letters, numbers, and characters -_

So, I have a text field that can contain only letters, numbers, hyphens, dots and underscores. I would like to validate it using Zend_Validate_Regex but this pattern does not work. Why?

/[a-z][A-Z][0-9]-_./

Here is my text element:

$titleSlug = new Zend_Form_Element_Text('title_slug', array(
    'label' => 'Title Slug开发者_开发技巧',
    'required' => FALSE,
    'filters' => array(
        'StringTrim',
        'Null'
    ),
    'validators' => array(
        array('StringLength', FALSE, array(3, 255)),
        array('Regex', FALSE, array('pattern' => '/[a-z][A-Z][0-9]-_./'))
    )
));

Your regex matches a string that contains a lowercase letter, an uppercase letter, a digit, a dash, an underscore and any other character, in that order. You need this:

/^[\w.-]*$/

^ and $ anchor the match at the start and end of the string.

\w matches letters, digits and underscore; together with the dot and dash they form a character class ([...]) which is repeated zero or more times (*).

how about this:

 /[a-zA-Z]*|\d*|-*|\.*|_*/