yes but you need to add the ?a for each position of the password length. for example if you think the password is 6 characters then you need
?a?a?a?a?a?a
for 8 characters you want
?a?a?a?a?a?a?a?a
and so on.
you don't need the -1 unless you are using it as a variable, which looks like this
-1 ?l?u?d?s ?1?1?1?1?1?1
that does the same as the above ?a example.
more examples
http://hashcat.net/wiki/doku.php?id=mask_attack
?a?a?a?a?a?a
for 8 characters you want
?a?a?a?a?a?a?a?a
and so on.
you don't need the -1 unless you are using it as a variable, which looks like this
-1 ?l?u?d?s ?1?1?1?1?1?1
that does the same as the above ?a example.
more examples
http://hashcat.net/wiki/doku.php?id=mask_attack