~rumpelsepp

Neovim is awesome. By this time it supports being configured using the Lua programming language. I am pretty happy with this, since I never got into vimscript…

I use neovim for everything that has to to with text. It can be programming, taking notes, configuring services, sorting data, or just reformatting files with macros. The fact that neovim runs in a terminal enables using it on a remote server via SSH. Since I use it for these tasks I often have to use my system clipboard (which is provided by wayland in my case).

I have a simple shortcut for this in my init.lua:

vim.api.nvim_set_keymap("", "<leader>y", '"+y', { silent = true })

Note: Since I use a German keyboard with the Neo2 layout I have mapped ä to the mapleader. There are most likely no collisions with existing shortcuts and ä is easier to type as \. :)

vim.g.mapleader = 'ä'

Yeah, that's it with the clipboard, I just hit <leader>y (in my case äy) and voilà, the yanked content is available via ctrl+v in my desktop. But when nvim runs on a remote server via SSH it doesn't work. nvim has so called clipboard providers which define certain commands that are called when the + or * registers are accessed. Using this technique, nvim offloads the handling of the system clipboard to external shell commands, in my case wl-copy for yank and wl-paste for paste. Since wl-copy cannot communicate with my wayland compositor (since the relevant UNIX domain socket is not available on the remote server) this just doesn't work.

There is a solution for this. Programs can communicate with the terminal via so called escape codes. The relevant command is called OSC52 (Operating System Command 52); see here; grep for clipboard. My terminal emulator mix of choice (tmux and foot) both support OSC52. Check if your terminal emulator supports OSC52; I know that alacritty supports OSC52 as well. I always use tmux in my terminal, especially on remote servers and its OSC52 clipboard can be enabled in the config:

$ cat ~/.config/tmux/tmux.conf
set-option -g set-clipboard on

Then out of the box this works:

$ echo "foo" | tmux load-buffer -w -  # remote server
$ wl-paste -n                         # local machine
foo

The other way round works like this[^1]:

$ echo "bar" | wl-copy    # local machine
$ tmux refresh-client -l  # remote server
$ tmux save-buffer -      # remote server
bar

In order to use this in nvim the relevant snippet for init.lua is this one:

if vim.env.TMUX then
    vim.g.clipboard = {
        name = 'tmux',
        copy = {
            ["+"] = {'tmux', 'load-buffer', '-w', '-'},
            ["*"] = {'tmux', 'load-buffer', '-w', '-'},
        },
        paste = {
            ["+"] = {'bash', '-c', 'tmux refresh-client -l && sleep 0.2 && tmux save-buffer -'},
            ["*"] = {'bash', '-c', 'tmux refresh-client -l && sleep 0.2 && tmux save-buffer -'},
        },
        cache_enabled = false,
    }
end

If you do not like tmux and want to use OSC52 direcly, I am experimenting with writing a tool for this. Perhaps it works, then I can release it sometime.

UPDATE: I did write a tool — oscclip which works somehow. It is available on Arch in the AUR or on PyPi.

[^1]: There was a bug in tmux preventing this. It is already merged: https://github.com/tmux/tmux/pull/2942