[TUHS] Abstractions

[M Douglas McIlroy]

>  - separation of code and data using read-only and read/write file systems

I'll bite. How do you install code in a read-only file system? And
where does a.out go?

My guess is that /bin is in a file system of its own. Executables from
 /letc and /lib are probably there too. On the other hand, I guess
users' personal code is still read/write.

I agree that such an arrangement is prudent. I don't see a way,
though, to update bin without disrupting most running programs.

Doug