Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site ucsfcgl.UUCP Path: utzoo!linus!decvax!decwrl!ucbvax!ucsfcgl!arnold From: arnold@ucsfcgl.UUCP (Ken Arnold%CGL) Newsgroups: net.unix Subject: Re: Alternate Shells Message-ID: <615@ucsfcgl.UUCP> Date: Fri, 16-Aug-85 23:43:51 EDT Article-I.D.: ucsfcgl.615 Posted: Fri Aug 16 23:43:51 1985 Date-Received: Mon, 19-Aug-85 22:03:52 EDT References: <10672@Glacier.ARPA> <575@bu-cs.UUCP> Reply-To: arnold@ucsfcgl.UUCP (Ken Arnold) Organization: UCSF Computer Graphics Lab Lines: 23 >>From: conor@Glacier.ARPA (Conor Rafferty) >>Subject: Alternate Shells >>Summary: Why is chsh fascist? > >>A quickie: 4.2BSD chsh does not allow the user to specify alternative >>shells - only "sh" and "csh" are permitted. Why is this? It seems >>ironically inappropriate in UNIX, where the shell is ``an ordinary, >>swappable user program'' and ``user-selectable system interfaces [...] >>become essentially trivial to implement'' [Ritchie & Thompson CACM 1974]. > >One obvious reason probably had more to do with the 'nuisance' of people >setting various things to be their shell and then finding out it was a >bad choice... I helped make this decision -- it was because people who left their terminals unattended for a few minutes (to relieve themselves, say) would find themselves with a strange shell the next time they logged on. This kind of prank became such a pain (besides being virtually unfixable without finding a super-user, a species of (alleged) person not always available when you have an assigment due the next morning) that we decided to turn off chsh to non-normal shells except for root. Ken Arnold