🚀 go-pugleaf

danpop@mail.cern.ch (Dan Pop) wrote:
>Can you use a Unix system without a shell?  Try to remove all the shells
>from your Unix system and see what you get :-)

   Absolutely.  You could have a user login on a *NIX system and in the
/etc/passwd entry for that user, have whatever binary you wish to provide the
user interface.  That could include a totally graphical interface if one so
desired.
>
>BTW, you found no contradiction:  Will Packard is perfectly right, Unix
>is not one or more shells, for the simple reason that the shells are a
>component of the Unix system.  The other components are the kernel and
>the system utilities.  All these components define a Unix system.

   Shells in *NIX are applications, pure and simple.  They are forked from the
login process based on the entry in /etc/passwd for whatever user is logging
in. In many installations, certain logins will cause the fork()ing and
exec()ing of some sort of window oriented application.  The *NIX OS is
basically the kernel and system call interfaces, plus perhaps, libraries.  Not
that this has a whole lot of relevence.
>
>The shell is to Unix what the finder is to MacOS.

   Actually, that analogy only works halfway.  finder is more like fork/exec
for MacOS, or perhaps init. 
>
>Dan
>--
>Dan Pop
-- 
Joseph Crowe
jcrowe@isd.tandem.com