illegal characters

[acctman]

hi i'm using this code to check for illegal characters in a username, i'd like to add a hypen and underscore as allowed characters.

 

//illegal characters in username?
        if (!ctype_alnum($en['user']))
            $err .= _reg_illegal.'<br>';

[EXiT]

This works for me...

if(!preg_match('/^[a-zA-Z0-9_-]+$/', $en['user']))
{
     ...Error Msg
}

[acctman]

This works for me...

if(!preg_match('/^[a-zA-Z0-9_-]+$/', $en['user']))
{
     ...Error Msg
}

 

so the above code would do a-Z  0-9 plus - and _ 

everything else would be rejected right? what's the +$ for?

[discomatt]

That's wrong. You must escape the hyphen or have it FIRST

 

/^[a-zA-Z0-9_\-]+$/

 

or

 

/^[-a-zA-Z0-9_]+$/

 

+ is a quantifier. It says match the class between 1 and infinite times, as many times as possible, giving back as needed.

$ matches the end of the string.

[acctman]

That's wrong. You must escape the hyphen or have it FIRST

 

/^[a-zA-Z0-9_\-]+$/

 

or

 

/^[-a-zA-Z0-9_]+$/

 

+ is a quantifier. It says match the class between 1 and infinite times, as many times as possible, giving back as needed.

$ matches the end of the string.

 

so the correct code would be

 

if(!preg_match('/^[a-zA-Z0-9_\-]+$/', $en['user']))
$err .= _reg_illegal.'<br>';

[discomatt]

Give it a shot. Looks good from here