Well, regex is powerful enough to decide if a password fails:

Not less than 6 characters: /\S{6,}?/

More than one character class: (/[a-zA-Z]/ && /[0-9]/ && /[!@#]/) (that last one is only a subset of what you could include)

You can also do the standard 'flip' through the /usr/dict for common words. (eg while (<DICT>) { if ($password =~ /$_/) { $flag = 1; last; } }).

But there doesn't seem to be any module for it. I think this is because the typical passwd program can vary from system to system depending on installation, distribution, and end-use security features.