Linux Shells

[Charles Steinkuehler]

Randy Weidman wrote:
> I was reading in a book, "Unix Using Linux" by Dent and Gaddis, where the 
> statement "All Linux Versions use the Bash Shell by default".
> 
> As I have only expertise in RedHat and Mandrake I was wondering if this 
> were true?

As a generalization, I suppose, but there are *LOTS* of linux 
distributions.  Most of the embedded and firewall/router type systems I 
know of use ash (or something even smaller) for a shell, if they run a 
shell at all.  There's no fundamental reason linux even needs a shell to 
run, just like you don't really need init (many embedded systems simply 
run their single application instead of init, and don't need the entire 
concept of runlevels, inittab, etc).

Remember, "linux" is just the kernel...the bulk of what gets added to 
make linux into a useful system is user-selectable from *LOTS* of 
options.  Just about everything from init to widget libraries for your 
window manager has multiple solutions, with the appropriate selection 
for your particular situation dependent on numerous variables.

SIDE NOTE:  This brings to mind a discussion I was having with a friend 
the other day about genetic algorithms.  The point was made that linux 
and the GPL have created what I suspect is the largest experiment to 
date in genetic algorithms, with the entire OS being the 'algorithm' 
that's constantly being re-invented and improved (and like all true 
genetic programs, occasionally takes big steps backwards and/or sideways 
:).  Kind of wierd to think about, but I think the analogy is appropriate.

-- 
Charles Steinkuehler
charles at steinkuehler.net