Brute force knowing some characters (but not their location)

[andreap]

Hi all,
i'm wondering if it's possible to do a brute force attack by knowing some characters of the password but not their location.

Obviously the most obvious solution is this:
-a 3 -1 '?l?d' '?1?1?1?1?1?1?1?1'
But knowing that the password contains the character "9" would rule out a lot of futile attempts.


If you were sure instead that the password contains only lowercase letters and that number:
-a 3 -1 '?l9' '?1?1?1?1?1?1?1?1'

Same problem here:
-a 3 -1 '?l9' '?1?1?1?1?1?1?1?1'
is very different than:
-a 3 -1 '?l9' '?1?l?l?l?l?l?l?l'
-a 3 -1 '?l9' '?l?1?l?l?l?l?l?l'
-a 3 -1 '?l9' '?l?l?1?l?l?l?l?l'
-a 3 -1 '?l9' '?l?l?l?1?l?l?l?l'
-a 3 -1 '?l9' '?l?l?l?l?1?l?l?l'
-a 3 -1 '?l9' '?l?l?l?l?l?1?l?l'
-a 3 -1 '?l9' '?l?l?l?l?l?l?1?l'
-a 3 -1 '?l9' '?l?l?l?l?l?l?l?1'

In conclusion yes, I could try like this but if I know more characters how should I do? Start a lot of executions? I hope there is something better ..

Thanks
Andrea P.