How do I run a shell command from .tmux.conf

Question

How do I run a shell command from .tmux.conf, or otherwise automatically when tmux launches, without having to hit any other command?

How can I create an alias, a function, or a script which boils down to, for example

tmuxirc -> tmux + irssi

Answer 1

It sounds like you want to externally invoke tmux from your shell rather than doing this from within tmux, so .tmux.conf is the wrong place. You can use a shell alias (place this in your .bashrc for reuse):

alias tmuxirc='tmux new-session -s irc irssi'

Answer 2

While it doesn't seem to be what you were looking for, the solution to:

How do I run a shell command from .tmux.conf

is run-shell, or, in its abbreviated form, run. From the tmux man page:

run-shell shell-command
               (alias: run)
         Execute shell-command in the background without creating a win-
         dow.  After it finishes, any output to stdout is displayed in
         copy mode.  If the command doesn't return success, the exit sta-
         tus is also displayed.

If you need to silently kick off a script in the background whenever you launch tmux, you could use run "command > /dev/null".

Answer 3

I do something similar with a script. When I want to fire up tmux with my development configuration I call it. The script itself looks like the following:

#!/bin/sh
tmux has-session -t development
if [ $? != 0 ]; then
    tmux new-session -s development -n editor -d
    tmux send-keys -t development 'cd /var/www/htdocs/' C-m
    tmux send-keys -t development 'vim' C-m
    tmux split-window -v -t development
    tmux split-window -v -t development
    tmux select-layout -t development main-horizontal
    tmux send-keys -t development:0.1 'cd /var/www/htdocs/' C-m
    tmux new-window -n console -t development
    tmux send-keys -t development:1 'cd /var/www/htdocs/' C-m
    tmux select-window -t development:0
fi
tmux attach -t development

What this gives me is a tmux session with 2 windows, window 1 has a Vim session in the top of the screen, with two terminals in the bottom 3rd or so of the screen, all pointed at my /var/www/htdocs/ directory. Window 2 is just a full screen console. Good thing about this is that it won't recreate the session if it's already there, it will just attach to it.

Answer 4

There's a display-message command in tmux, from its man page:

display-message [-p] [-c target-client] [-t target-pane] [message]

(alias: display)

Display a message. If -p is given, the output is printed to stdout, otherwise it is displayed in the target-client status line. The format of message is described in the FORMATS section; information is taken from target-pane if -t is given, otherwise the active pane for the session attached to target-client.

And in FORMATS section, there is a variable named session_name, it will be replaced with the name of the session if you use it in format #{session_name}.

Try to run tmux display-message -p '#{session_name}' when you are in a tmux session. Maybe you will see a number, it is the id of the session you attached. Run tmux ls to check the session list.

However, when you start up a tmux by tmux new -s myproject, you will see myproject as the output, but not a number. Because you specified the name of the session when you start tmux.

So, my solution is to put a piece of code in ~/.bashrc file:

# [tmux] load scripts in ~/.tmux on creating a new pane
# load order: __before__.sh, ${session_name}.sh, __after__.sh
function tmux_load_startup_scripts_by_session_name() {  
  if [[ -n ${TMUX} ]]; then
    local env_before_script="${HOME}/.tmux/__before__.sh"
    [[ -f "${env_before_script}" ]] && { . "${env_before_script}"; }
    local env_main_script="${HOME}/.tmux/$(tmux display-message -p '#{session_name}').sh"
    [[ -f "${env_main_script}" ]] && { . "${env_main_script}"; }
    local env_after_script="${HOME}/.tmux/__after__.sh"
    [[ -f "${env_after_script}" ]] && { . "${env_after_script}"; }
  fi
}
tmux_load_startup_scripts_by_session_name  

Usage

mkdir ~/.tmux
cat "__before__.sh" > ~/.tmux/__before__.sh
cat "__after__.sh" > ~/.tmux/__after__.sh
cat "sample.sh" > ~/.tmux/sample.sh
tmux new -s sample

You will see output on each panel you create:

__before__.sh
sample.sh
__after__.sh

The advantage of this solution is you can specify different scripts for different projects or environment.