[NTLUG:Discuss] What settings do I want?

[Douglas King]

I am trying to "tighten down" my web server some more....finding folks 
doing SSH into it that SHOULD only have FTP access.  This is the selection 
I have, what setting do I set a user to IF they should ONLY have FTP access 
to a Red Hat server...?

/bin/sh

/bin/csh

/bin/false

/bin/bash

/sbin/nologin

/bin/sync

/sbin/shutdown

/sbin/halt

/dev/null

/bin/nologin

/bin/bash2

/bin/ash

/bin/bsh

/bin/tcsh

Other...


Better yet, could you tell me what each of these does...or means?