I have a need to allow directory access to a particular user on my file system. I want this user to be unable to access any other directory in my file system (initially anyway. It may need access to some directories later).

For example: I have a directory called /opt/mydir. - I want my dedicated user to only be able to access this directory, and nothing else. - I want all other users to be able to access this directory as normal.

I'm new to Linux and its permissions. I've read a fair bit of background material but I'm a little confused. Is there anyway to revoke permissions to /opt/mydir for a single dedicated user?

A possible flawed method would be to only allow access to /opt/mydir and exclude every other user. This won't work because I want all other users to work as normal; accessing the directory.

I'm working on Solaris 10.

Any suggestions are appreciated.