Running Interactive Fiction Doors

Hey all, I have a question. If you want to run an IF game that was not made to
be a door, as a door, such as an infocom game, how do you keep the users
from saving their game in any arbitrary directory.  For example how do 
you keep them from saving their game as c:\autoexec.bat or something?
Is there a door program that is available to interpret these games? If so can 
someone point me in the right direction?

I'm thinking specifically about adding an IF game I made years ago to my BBS,
it was written in inform7 and I've been able to get it to sort of work as a
door by running it through git for dos and having that run through DoorWay but
I can't seem to find a way to prevent the user from saving (or attempting to
load) their game from any arbitrary directory.
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