Using zsh's line editor to wrap around subprocesses

Question

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.

Answer 1

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