A backup script was accidentally run a few directories below where it should have. the chmod -R 755 has affected about 20 website structures that shouldn't have been touched.

My curiosity now goes to, how can one undo such a change?
Is it at all possible?

Is there some way of outputting the current state of file attribs to a file, as say, a daily/weekly cron job?

The hope with that being that parsing that file, could restore the previous attribs and permissions should something like this happen again.

Anyone?