Switching in Vim doesn't work (Solution also posted here)

[BriHan-Tech]

Problem

When I have windows in vim, I am unable to switch between them; however, I am able to switch between Vim windows and Tmux Panes

System Specs

1. Apple M3 Pro Sequoia 15.1.1
2. NVIM v0.10.2
3. tmux 3.5a

Solution

From some debugging work, I realized the is_vim check currently doesn't always accurately return if the process is a vim process or not. This is because vim processes could be nested.

To properly check if the process is a vim process or not, I have wrote the script that goes through the descendent processes to check if there is a vim process or not.

Here is the repository with my solution: https://github.com/BriHan-Tech/is-vim

Note:

1. I definitely know there is a better solution; however, for now, I just needed it to work.
2. pstree might require users to install something extra; however, you can probably do pstree with regex to get an one-line solution.

Here is the code for my solution:

is_vim.sh

#!/usr/bin/env bash

pane_pid=$(tmux display -p "#{pane_pid}")

[ -z "$pane_pid" ] && exit 1 

# Retrieve all descendant processes of the tmux pane's shell by iterating through the process tree.
# This includes child processes and their descendants recursively.
descendants=$(ps -eo pid=,ppid=,stat= | awk -v pid="$pane_pid" '{
    if ($3 !~ /^T/) {
        pid_array[$1]=$2
    }
} END {
    for (p in pid_array) {
        current_pid = p
        while (current_pid != "" && current_pid != "0") {
            if (current_pid == pid) {
                print p
                break
            }
            current_pid = pid_array[current_pid]
        }
    }
}')

if [ -n "$descendants" ]; then

    descendant_pids=$(echo "$descendants" | tr '\n' ',' | sed 's/,$//')

    ps -o args= -p "$descendant_pids" | grep -iqE "(^|/)([gn]?vim?x?)(diff)?"

    if [ $? -eq 0 ]; then
        exit 0
    fi
fi

exit 1

tmux.conf

bind-key -n 'C-h' if-shell '~/.config/tmux/plugins/is-vim/is_vim.sh' 'send-keys C-h' 'select-pane -L'
bind-key -n 'C-j' if-shell '~/.config/tmux/plugins/is-vim/is_vim.sh' 'send-keys C-j' 'select-pane -D'
bind-key -n 'C-k' if-shell '~/.config/tmux/plugins/is-vim/is_vim.sh' 'send-keys C-k' 'select-pane -U'
bind-key -n 'C-l' if-shell '~/.config/tmux/plugins/is-vim/is_vim.sh' 'send-keys C-l' 'select-pane -R'

bind-key -T copy-mode-vi 'C-h' select-pane -L
bind-key -T copy-mode-vi 'C-j' select-pane -D
bind-key -T copy-mode-vi 'C-k' select-pane -U
bind-key -T copy-mode-vi 'C-l' select-pane -R

[S1M1S]

Your solution works for me on:

Apple M4 Sequoia 15.1.1
NVIM v0.10.2
tmux 3.5a

Thanks!