[murrain]

$password = str_shuffle((substr(str_shuffle('ABCDEFGHIJKLMNOPQRSTUVWXYZ'),0,3).substr(str_shuffle('abcdefghijklmnopqrstuvwxyz'),0,3).substr(str_shuffle('0123456789'),0,2).substr(str_shuffle('!@#$'),0,2)));

[murrain]

With that it will always contain 3 capital letters, 3 lower case letters, 2 numbers, and 2 punctuation.