Re: ^Z signal

[pete@minster.york.ac.uk]

>From rog@ohm.york.ac.uk Mon May 17 08:12:52 0400 1993
>
>I'm in favour of %read, but could we keep things like gnu readline
>out of it ? If line editing is desired, an external program is really
>more appropriate - it's only when reading non-interactively that the
>performance really matters.
>
>  cheers,
>    rog.

A simple %read builtin would save us all a lot of time and would enable
us to get rid of many sh and rc scripts... but again I must stress
_KEEP IT SIMPLE_ for three reasons:

(1) Es is already quite a large binary (it's the largest of the six shells
on our Sparcs; adding fancy prompting and readline will only make it larger
still...                                                                   
                                       
(2) Assuming gnu-readline will work on someone's terminal is not a wise
thing to do these days. Some of us run decent terminal emulators (9term!)
which have sensible editing features and do away with the need for tedious
cursor-addressing; just give us something that reads from whatever file
descriptor is passed rather than messing around...            

(3) Adding bells and whistles to %read will result in more ``hidden
parameters'' and special cases that have to be rewritten internally. As
Alan Perlis said: ``syntactic sugar causes cancer of the semicolon''...    

If people must have line editing then they can use ile, or atty, or any one
of the other pty-based front ends; they also have the benefit that since
they grab all the input and pass it on to the shell or whatever it's
running, they work for _all_ programs, not just the shell.                 

pete
--
*Peter Fenelon -- Research Associate -- Software Safety Assessment Procedures*
Dept. of Computer Science, University of York, York, Y01 5DD (+44/0)904 433388
EMAIL: pete@minster.york.ac.uk ``You are what you drink and I'm a bitter man''