ANNOUNCE: GHC version 6.10.1 - EditLine / terminal incompatibility?

Philip K.F. Hölzenspies p.k.f.holzenspies at
Fri Nov 21 05:59:35 EST 2008

On Friday 21 November 2008 10:49:47 Jules Bean wrote:
> Philip Hölzenspies wrote:
> > Also, there are no de facto escape sequences, because special keys (like
> > function and arrow keys) have different sequences on different
> > terminals. A useful tip that may be useful to include in the wiki is an
> > easy trick that will help you find out your terminals escape sequences.
> > I usually just like to start an application that has no editline or
> > readline capabilities and press the keys. Telnet is one of my favorite
> > applications for this purpose.
> But this is abhorrent.
> The whole point of the existence of termcap and libraries which build
> upon it (ncurses, readline, editline, etc) is so that individual users
> do not have to work out what the escape sequences produced by their
> terminal are.
> Something must be very very broken : surely it is not expected behaviour
> for editline to need configuration in this way?

One can call it broken, another will say users should settle for the default 
behaviour. Neither readline, nor editline *need* configuration this way, 
because they do come with sensible defaults. However, some people want custom 
behaviour and they'll have to figure out how stuff works for their machine.

I think a sensible purpose of a Wiki is to help people get some of the more 
tricky business done. Also, I don't see what is wrong with typing in terms of 
escape sequences per se, but for those that have something against it; 
there's bound to be some program somewhere that will allow you to type <up> 
instead of ^[[A. The upside of the telnet tip, is that it works on many *NIXs 
and their derivatives. It even works on OSX, so it's a 
one-size-fits-(almost)-all tip.


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