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Tmux login session script

Here's the idea: when you log in to your computer you always have to start the web browser, email, etc. So you create a script that starts them all at once. The script below is an extension of that concept. It creates a tmux session (tmux is like screen but better) and runs each program in its own window. There are a number of advantages to this approach:

  • You can shut everything down by attaching to the tmux session and hitting Ctrl-C in each window.
  • If a program exits, you can restart it by running this script again. It only starts programs that are not already running. This beats restarting programs manually especially if you have complicated command line parameters you like to pass.
  • Stdout/stderr messages can be seen by attaching to the terminal. Additionally, all output is written to log files.
  • Not all programs need be started by default. For instance, in the example below Sage is not started automatically. It is started when I run session-start.sh sage and is only started if it is not already running.
Download via the following link: session-start.sh 
#!/bin/bash

session="bg-apps"
logs_dir=~/session-logs

mkdir -p "$logs_dir"

# Start session if it doesn't exist
if (tmux has-session -t "$session" 2> /dev/null); then
	echo "Session $session exists."
else
	echo "Starting session $session."
	# tmux doesn't allow nested sessions, and if this situation is not caught here then the
	# 'tmux new-session' command will fail.  Although, since the session is being started
	# detached, it is probably okay.  So maybe it would be better to just temporarily unset the
	# TMUX variable before running new-session.
	if [ "$TMUX" != "" ]; then
		echo "Error: cannot start session from within tmux."
		exit
	fi
	tmux new-session -d -s "$session"
fi

function run_in_window {
	name="$1"
	cmd="$2"
	if (tmux list-windows -t "$session" -F '#{window_name}' |grep "^$name\$" >/dev/null); then
		echo "Already running: $name"
	else
		echo "Starting: $name"
		echo "Started at $(date)" >  $logs_dir/$name
		echo "Command: $cmd"      >> $logs_dir/$name
		echo "-------"            >> $logs_dir/$name
		# Create new window and run command.
		tmux new-window -t "$session" -n "$name" "$cmd"
		# Start logging.
		tmux pipe-pane  -t "$session:$name" "cat >> \"$logs_dir/$name\""
	fi
}

function start_something {
	name="$1"

	case "$name" in
	gkrellm)     run_in_window "$name" "gkrellm" ;;
	chrome)      run_in_window "$name" "google-chrome --disk-cache-size=50000000 --media-cache-size=50000000 --disk-cache-dir=/mnt/ramdisk/chrome-cache --disable-webgl --enable-seccomp-sandbox" ;;
	thunderbird) run_in_window "$name" "thunderbird" ;;
	akregator)   run_in_window "$name" "akregator --nofork --hide-mainwindow" ;;
	sage)        run_in_window "$name" "~/apps/sage/sage -n" ;;
	*)           echo "Unrecognized command: $1"
	esac
}

if [ "$1" = "" ]; then
	start_something "gkrellm"
	start_something "chrome"
	start_something "thunderbird"
	start_something "akregator"
else
	start_something "$1"
fi

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