How do I emulate Unix “set-uid”?
In other words: How do I write a program which can update a database but not allow the user to play with the database outside my program? You have hit on a problem which has confronted Primos developers since time immemorial. The root of the problem is that there is _no_ way to mark an executable image (EPF) “privileged” so that when the program is running, a directory or file can be accessed which is normally “ACLed out” to the user when he/she is sitting at the command prompt. For example: if you have a directory containing mail, for user A to run a program which appends to user B’s mail file, user A must be able to do the same at the command line. There are two ways round this. One is to use password directories with the password embedded in the program. You have to be careful to encrypt the password and it’s always vulnerable to discovery. The second way is to use a server. In our example, you fire up a server called “MAIL_SERVER” and set the ACL on “MAILDIR” to MAIL_SERVER:ALL $RE
