lhb@duke.cs.duke.edu (Pete Boyd) (07/13/87)
We are planning to e AT&T equipment for some undergraduate courses to be offered in the fall. I would like to offer these students features of the UNIX C shell. Many thanks to anyone who has knowledge of a port of the C shell to System V.
dg@wrs.UUCP (David Goodenough) (07/14/87)
In article <9904@duke.cs.duke.edu> lhb@duke.cs.duke.edu (Pete Boyd) writes: >We are planning to e AT&T equipment for some undergraduate courses to >be offered in the fall. I would like to offer these students features of >the UNIX C shell. Many thanks to anyone who has knowledge of a port of >the C shell to System V. Could be a problem - as far as I know only BSD UNIX supports job control which was one of the main reasons for the C shell. AT&T Unix variations simply don't have it. You'll still be able to get history working (for that matter I've added a history mechanism to the bourne shell - took about three evenings if I remember) P.S. I may be wrong about BSD being the only UNIX with job control in which case I've got my asbestos suit ready :-) -- dg@wrs.UUCP - David Goodenough +---+ | +-+-+ +-+-+ | +---+
wcs@ho95e.ATT.COM (Bill.Stewart) (07/16/87)
In article <9904@duke.cs.duke.edu> lhb@duke.cs.duke.edu (Pete Boyd) writes: : We are planning to use AT&T equipment for some undergraduate courses to : be offered in the fall. I would like to offer these students features of : the UNIX C shell. Many thanks to anyone who has knowledge of a port of : the C shell to System V. There may be commercial vendors who sell csh for the 3B series, but they're not in the AT&T Toolchest, which is the mechanism for selling unsupported internal software. In article <242@wrs.UUCP> dg@wrs.UUCP (David Goodenough) writes: : Could be a problem - as far as I know only BSD UNIX supports job control Which features of C shell matter to you? - C-like Syntax (for this you really need csh) I've always found it easier to write programs in /bin/sh than in csh. Korn Shell (ksh) is upward-compatible with /bin/sh, and has a number of additional programming features. - History The Korn Shell (ksh) history mechanism supports a csh-like interface and an interactive-editor interface which is easier to use. - Job Control This is really an operating system feature, not a shell feature, though the shell needs hooks to request job-control service. Ksh supports job control on 4.*BSD. On System VR2 you don't have "real" job control, but you do have "shell layers" which help somewhat, and can be accessed from /bin/sh or ksh. -- # Bill Stewart, AT&T Bell Labs 2G-202, Holmdel NJ 1-201-949-0705 ihnp4!ho95c!wcs
Karl.Kleinpaste@cbstr1.att.com (07/16/87)
dg@wrs.UUCP writes: >[SysV csh wanted.] Could be a problem - as far as I know only BSD UNIX supports job control which was one of the main reasons for the C shell. No, the csh was written before BSD had job control. Pieces of it predate the existence of anything identifiable as "BSD." Job control was hacked in (somewhat crudely, in my opinion; little bits and pieces of it seem to be all over the place) when 4BSD came along. AT&T Unix variations simply don't have it. Yes and no. SysV doesn't support SIGTSTP and friends, of course. But I've mentioned from time to time (as have others) that you can go a long way toward simulating job control using ptrace(2). My port of csh (landlocked inside AT&T, sigh) does this. From the user's point of view, it is very nearly indistinguishable from 4BSD. P.S. I may be wrong about BSD being the only UNIX with job control in which case I've got my asbestos suit ready :-) No asbestos needed, just a little erroneous history... Karl
kimcm@olamb.UUCP (Kim Chr. Madsen) (07/16/87)
In article <242@wrs.UUCP>, dg@wrs.UUCP (David Goodenough) writes: > Could be a problem - as far as I know only BSD UNIX supports job control > which was one of the main reasons for the C shell. AT&T Unix variations > simply don't have it. You'll still be able to get history working (for > that matter I've added a history mechanism to the bourne shell - took > about three evenings if I remember) > Seems like you got the story all wrong... The csh(1) was invented loooong before job control in the BSD systems, job control was first introduced with 4.1BSD (as far as I remember), but csh was around even in the days of v7 UNIX (and I suspect even in v6 - though I'd never used that version). The main reasons for the csh (or why many people considered csh superior to the Bourne Shell (sh(1))) is that it had such nice features as: a) Command history (with execution of earlier commands) b) Editing utilities in earlier commands. c) A C-like syntax - which made it easier for some to make shell scripts - instead of using the Algol-68 based /bin/sh. d) More build-in commands to speed up performance. e) The alias concept - for personalizing the interface to the shell. As for the availability of csh on SYSV machines: 1) No csh(1) is not standard SYSV, an unconfirmed rumor says that when AT&T bought the rights to BSD systems the csh was considered a separate product which the folks behind Berkerly was willing to sell at the same price as for the whole BSD system, which AT&T refused... 2) Some vendors supply their SYSV machines with Berkerly enhancements such as the csh, strings, more, sockets etc. 3) SCO Xenix V comes with a csh as well as other ucb utilities - partly due to the bonds to v7 UNIX it still has. 4) Some time ago a PD csh emulator (actually a bourne shell script) was posted to the net it was called bsh. I don't have it but I suspect it is still around on many pure SYSV machines. Kim Chr. Madsen.