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Is it possible to use zsh's built-in line editor (zle) to feed input to a subprocess? That is, I would like to run zlewrap mycommand where zlewrap is a zsh function and mycommand is any program that just reads lines from stdin; zlewrap would effectively provide zle's line-editing capabilities to mycommand. This is on the model of rlwrap which does just this, but with readline and not zle for line editing.

Kevin
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Gilles 'SO- stop being evil'
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    This looks helpful: http://www.zsh.org/mla/users/2004/msg00917.html . It's not as easy as a single command, but you can adapt this script to your program (read the follow-ups for corrections). – imgx64 Jan 07 '11 at 07:58
  • One problem I have when I think of solutions is how do you indicate when you want to be 'editing' in the ZLE and when you want to be waiting for the 'mycommand' to return? Does it only ever return one line? – polynomial Aug 27 '11 at 02:42
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    @polynomial wrappers like this return one line at a time to the process behind them. Use of rlwrap is quite widespread and you've probably used it. Think about the little pseudo shell things you get in things like mysql, sqlite, lftp, etc. They all have some implementation of a line editor that returns on line or block of lines at a time to the actual processor behind them. rlwrap does hits quite neatly for any program that accepts STDIN, but it would be nice to have zle style bindings and abilities rather than readlines which are someone less extensive. – Caleb Jan 07 '12 at 23:26
  • Have you looked at the manual for zsh - http://www.cs.elte.hu/zsh-manual/zsh_14.html? - I don't quite understand your question, but Googled the title, and found that page. It might help, but I don't know. – Kevdog777 Aug 22 '12 at 08:33
  • @Kevdog777 Did you read the page you found? It's the manual from a zsh version from 16 years ago. I fail to see how you could possibly think it might be helpful. I have read the manual, as you might imagine. There is probably something to be done with zpty but the answer is not in the manual. – Gilles 'SO- stop being evil' Aug 22 '12 at 11:58
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    Ok, I was just trying to help, as I see your question hasn't been answered in over a year. Sorry my comment wasn't good enough. – Kevdog777 Aug 22 '12 at 12:04

1 Answers1

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Here is how you can do it if using GNU screen:

Put a file called zf in your $PATH with:

#! /usr/bin/env zsh
zmodload -i zsh/zle
trap 'printf "\03"; exit' INT
HISTSIZE=100
while a=; vared -p "${2:-zle> }" -eh a; do
{
  s=$(stty -g)
  stty -echo -iexten -isig lnext '' werase '' eof '' rprnt '' kill ''
  printf "%s\r" "$a"
  print -rs -- "$a"
  stty "$s"
} < $1
done
printf "\04"

And then, run the filter in screen as

<Ctrl-A>:exec .!. zf /dev/pts/x "> "

Replace /dev/pts/x with the actual Windows pty (output of tty command in the window), and "> " with the prompt to display.

There will be occasional display glitches as both zsh and the application will write to the terminal in an unconcerted way.

Original at http://www.zsh.org/mla/users/2005/msg00186.html

Stéphane Chazelas
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  • Any chance of some explanation of how this works? What does ".!." mean? Why does it need to be run in screen? – Ben Aug 31 '20 at 20:42