[TUHS] Origin year of BSD csh?

Sven Mascheck mascheck at in-ulm.de
Mon Jun 27 21:27:32 AEST 2016


On Sun, Jun 26, 2016 at 01:32:23PM -0500, Ronald Natalie wrote:
> I added JOB control to the SV  (and later SVR2) Bourne Shell.
> Then they beat on me for not having command like editing in (a la TCSH),
> so I added that.

How interesting, I will try to bother you (perhaps directly) about
in-depth informations :-)


I've always been intrigued by the fact that traditional Bourne shell and
Almquist shell haven't implemented history or command line editing.

I found two interesting references about this:

- Ash announcement, "A reimplementation of the System V shell":

  "I conclude by listing a few features that I have omitted intentionally.

   3.  History.  It seems to me that the csh history mechanism is
       mostly a response to the deficiencies of UNIX terminal I/O.
       Those of you running 4.2 BSD should try out atty (which I am
       posting to the net at the same time as ash) and see if you
       still want history."

- From an article from D. Korn, "ksh - An Extensible High Level Language":

  "Originally the idea of adding command line editing to ksh was
   rejected in the hope that line editing would move into the terminal
   driver. However, when it became clear that this was not likely to
   happen soon, both line editing modes were integrated into ksh and
   made optional so that they could be disabled on systems that provided
   editing as part of the terminal interface."

I believe it's a real pity that it hasn't been implemented in terminal
drivers in general.

Or do I overlook possible disadvantages?  What could be downsides,
apart from possibly inconsistent behaviour across systems?

Sven


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