How can I use mouse=a for local and remote work?

Question

I do use the same vimrc on my local machine and on a remote machine to which I connect through SSH. I keep the vimrc synced between the machines for commodity. My issue starts when I set mouse=a, I really like using it since I do have a lot of stuff in listchars=.

On my local machine, to copy to the primary or clipboard buffers I let the mouse enter visual mode (selectmode=) and do "+y or "*y. That's all fine. On the remote machine I force mouse= to be empty and use the terminal's copy and paste functions.

If I enable mouse=a on the remote machine I can't copy and paste from it anymore because Vim takes over the mouse and the terminal never sees the selection. For now I'm lucky that the remote machine have Vim 7.4, and since I use Vim 8.0 on my local machine the following works:

if 800 >= v:version
  set mouse=a
else
  set mouse=
endif

But it will break shortly since I'm about to update Vim on the remote machine.

I've tried connecting with ssh -X and ssh -Y to check if I can make the mouse work but without success. The selection works but the buffers (on the local machine) are not updated with the yank. The Vim process on the remote machine has a GUI compiled in and there is a Xorg running there, but the Vim process runs on that side of the connection and the Xorg buffers used are on that side. (Yes, this makes things more complicated.)

• Is there a way to make Vim use the Xorg buffers on the connecting machine?
• Or, is there a way (in VimScript) to test whether Vim is running in an SSH session as opposed to a local PTY?

Answer 1

It works for me. I have ForwardX11 yes in my ~/.ssh/config file, which should have the same effect as running ssh with -X, and I started vim on the remote machine as vim -N -u NONE -i NONE to make sure my configuration wasn't affecting anything, then executed :set mouse=a. I entered some text into vim, then selected some of it with the mouse, then pasted it into gvim running on the local machine.

One way I test X11 forwarding over SSH is to run xclock & on the remote machine and verify that the clock appears on the local machine.

To test in a Vim script whether you are running over SSH, you can test for the presence of one of the variables ssh sets on the remote machine, e.g.,

if exists("$SSH_CONNECTION")