Another question about mask to deal with space

[mastercracker]

But if it occurs '?a?a?a?a?a?a?a ' or maybe some other special characters, I do not know how to deal with it.

There is not much thinking to do about this. You have to try

Code:

'?a?a?a?a?a?a?a '

Then either the masks with each symbols like

Code:

'?a?a?a?a?a?a?a!'
'?a?a?a?a?a?a?a$'
...

or use this:

Code:

'?a?a?a?a?a?a?a?s'