mark@umcp-cs.UUCP (10/21/83)
A couple of other things that would be affected by where the shell was:
-A user shell would mean that the rest of the operating system
had to bring full power out to the user level. This would mean that
user programs to do strange operating system things would be writtable:
a plus!
-Kernel shells can keep privileges to themselves for which there
is no possibility of the user ever doing. This can make for
a user friendly system if other things are right, but it is
definitely expert-unfriendly. There may be some things which
cannot at all be programmed at all except through baroque
sets of command language calls which may be impossible to do
from within a users program.
(One of the things that sold me on Unix--I knew that whatever
the shell could do I could do, and so whenever it did something
I really admired I would go read the code to find out how.
This was not true on any previous operating system I had worked on.)
--
spoken: mark weiser
UUCP: {seismo,allegra,brl-bmd}!umcp-cs!mark
CSNet: mark@umcp-cs
ARPA: mark.umcp-cs@CSNet-Relay