Binding a key sequence to a macro

[hokuda]

This is relevant with the issue #47.
I have used peco for history expansion on bash for the last years. Adding the following code in my .bashrc, my ctrl-r invokes peco:

_complete_history() {
    local l=$(HISTTIMEFORMAT= history | tac | sed -e 's/^\s*[0-9]*  //' | peco --query "$READLINE_LINE")
    if [ "${l}x" != "x" ]; then
        READLINE_LINE="$l"
        READLINE_POINT=${#l}
    fi
}
bind -x '"\C-r": _complete_history'

If the rlwrap has the feature like the bind command of bash to bind a key sequence to a macro, it augments the rlwrap's history expansion feature and gives the rlwrap more flexibility.

[hanslub42]

There has been some discussion on bug-readline, about doing this for readine itself, where the conclusion was that this is not so simple. rlwraps hotkey is very similar, however: CTRL+R could be bound to rlwrap-hotkey, where the hotkey handler could do something along the lines of your example.

Problem: in bash, the hotkey handler is a shell function that can "see" everything because it runs in the same process as the shell itself. A filter is a separate, lonely process that can not look into rlwrap nor the rlwrapped command. cloak_and_dagger() can pry some information from the latter, but rlwrap itself is a black box.

A possible solution would be to send as much information as possible in a HOTKEY message: not only the current input line, but e.g. also the current history. The handler would have to be something like this

$filter -> hotkey_handler(sub {
   my($key, $input_line, $cursor_position, $history, $history_position, ....) = @_
   if ($key == control('R')) {
         my ($new_line, $new_cursorpos) = use_peco_to_get_a_line($history);
         return("", $new_line, $new_cursorpos, $history, $history_position,....);
   }
}

This would subsume the current rlwrap-edit-history function as well, and thus get rid of some code (at the expense of a slightly more complex hotkey handler)

If sending the complete history for every hotkey keystroke is a bit too much, I could also implement a rlwrap-hotkey-without-history function, for those hotkeys that don't need the complete history

[hanslub42]

I worked this out in branch hash_history, and this looks quite promising. History edit is now done in a few lines of perl (or python), and the existing --multi-line support could also easily be subsumed under rlwrap-hotkey. I cannot easily try peco on my linux machine, but I don't see why this wouldn't be straightforward as well.

One little twist should/will be added to the hotkey handler: if the returned input line ends with a newline, immediately accept the result, otherwise keep editing. So, if (and only if) we e.g. put two empty lines before a history line (or e.g. end a multi-line edit with a '!') accept the result

[hokuda]

Thanks a lot for the great work! That is what I really want! I added peco handler to the handle_hotkeys script and it works fine! Please review my pull request which has a peco handler and a minor bug fix.

[hanslub42]

All merged and done. Closing.