Tmux: How can I create "session > window > pane" and run a command in the pane?

Question

I'd like to do the next from a bash script:

• Create a session named "my_session".
• Create a window named "my_window" inside of that session.
• Create two pans named "my_pan1" and "my_pan2" inside of that window.
• Send a command inside of "my_pan1".
• Send a command inside of "my_pan2".

How would you approach this?

Answer 1

This tmux.sh script worked on my tmux 3.0a and after adding this: set -g pane-border-format "#{@mytitle}" in my .tmux.conf (see why in comments bellow the scipt). You might have to add this: set -g pane-border-status bottom in your .tmux.conf as well. With following command you name your session "ses", your window "win", pane 0 "p1" and pane 1 "p2":

tmux.sh ses win p1 p2

#!/bin/bash
    
session=$1
window=$2
pan1=$3
pan2=$4
    
#Get width and lenght size of terminal, this is needed if one wants to resize a detached session/window/pane
#with resize-pane command here
set -- $(stty size) #$1=rows, $2=columns

#start a new session in dettached mode with resizable panes
tmux new-session -s $session -n $window -d -x "$2" -y "$(($1 - 1))"
tmux send-keys -t $session 'echo "first command in 1st pane"' C-m
    
#rename pane 0 with value of $pan1
tmux set -p @mytitle "$pan1"

#split window vertically
tmux split-window -h
tmux send-keys -t $session 'echo "first command in 2nd pane"' C-m
tmux set -p @mytitle "$pan2"

#At the end, attach to the customized session
tmux attach -t $session

I had a lot of trouble to rename the panes because tmux select-pane -t $window.0 -T $pan1 should work but as stated here: https://stackoverflow.com/questions/60106672/prevent-tmuxs-pane-title-from-being-updated some updates of pane titles can be done by applications inside tmux. So I used the tricks given in the answer in the previous link (Nicholas Marriott gave also a solution for tmux version older than 3.0a)

Answer 2

A shorter way to do it. This example spawns 4 panes in grid.

#!/bin/bash
sh="/usr/bin/env sh" # You can also choose zsh.
SESSION="misc"       # Session name.
WINDOW="experiments" # Window name.

tmux kill-session -t "$SESSION" 2>&1
tmux start \; new-session  -d -s "$SESSION" -n "$WINDOW" "$sh -c \"echo 'first shell'\"; $sh -i" \;
tmux split-window "$sh -c \"echo 'second shell'\"; $sh -i" \;
tmux split-window "$sh -c \"echo 'third shell'\"; $sh -i" \;
tmux split-window "$sh -c \"echo 'fourth shell'\"; $sh -i" \;
tmux select-layout tiled \;
tmux attach -t "$SESSION" \;
tmux switch -t "$SESSION"