I wrote a script the other day designed to help me download and edit files faster. In part of the script, I wanted to open Vim in an existing Tmux pane, and in the process I learned about the
tmux send-keys command. Here's how it works:
$ tmux send-keys -t 3 "vim" Enter
send, sends your string of commands to your pane (
t) of choice. Running the above opens Vim in pane #3.
-t flag accepts negative numbers, too, like an array index. In my version of the above command, I send the keys to pane
-1, the last pane on the screen, which is where I keep Vim in my Tmux session.