Run a Bash Script in tmux at Login with Auto-Restart & Logging

You can start a Bash script automatically in tmux at login on Arch Linux without systemd, and now also log its output for easier monitoring. This guide shows:

1. Auto-Attach - attach immediately.
2. Background - run detached.
3. Auto-Restart - restart if the script crashes.
4. Logging - save output to a file.

Simple (No Logging)

Step 1: Create ~/tmux_simple.sh

#!/bin/bash

SESSION="fbses"

# Check if the session already exists
tmux has-session -t $SESSION 2>/dev/null

if [ $? != 0 ]; then
    # Session doesn't exist, create it and run the Python script
    tmux new-session -d -s $SESSION
    tmux send-keys -t $SESSION "python3 /home/fb/autostart/myprogram/run.py" Enter
fi

# Attach to the session
tmux attach -t $SESSION

Make it executable:

chmod +x ~/tmux_simple.sh

Step 2: Call it from ~/.bash_profile

[[ -f ~/.bashrc ]] && . ~/.bashrc
/home/fb/tmux_simple.sh

Auto-Attach with Auto-Restart and Logging

Step 1: Create ~/tmux.sh

#!/bin/bash

SESSION="fbses"
SCRIPT="/home/fb/autostart/myprogram/run.py"
LOG="/home/fb/autostart/myprogram/run.log"

# Check if session exists
tmux has-session -t $SESSION 2>/dev/null

if [ $? != 0 ]; then
    # Create session and run Python script with restart loop and logging
    tmux new-session -d -s $SESSION "while true; do python3 $SCRIPT >> $LOG 2>&1; echo 'Script crashed. Restarting in 5s...' >> $LOG; sleep 5; done"
fi

# Attach automatically
tmux attach -t $SESSION

Make it executable:

chmod +x ~/tmux.sh

Step 2: Call it from ~/.bash_profile

[[ -f ~/.bashrc ]] && . ~/.bashrc
/home/fb/tmux.sh

Background Only with Auto-Restart and Logging

Step 1: Create ~/tmux_bg.sh

#!/bin/bash

SESSION="fbses"
SCRIPT="/home/fb/autostart/myprogram/run.py"
LOG="/home/fb/autostart/myprogram/run.log"

# Check if session exists
tmux has-session -t $SESSION 2>/dev/null

if [ $? != 0 ]; then
    # Create session and run Python script in restart loop with logging
    tmux new-session -d -s $SESSION "while true; do python3 $SCRIPT >> $LOG 2>&1; echo 'Script crashed. Restarting in 5s...' >> $LOG; sleep 5; done"
fi

# Inform the user
echo "tmux session '$SESSION' is running in the background."
echo "Use 'tmux attach -t $SESSION' to view it."
echo "Script output is logged to $LOG"

Make it executable:

chmod +x ~/tmux_bg.sh

Step 2: Call it from ~/.bash_profile

[[ -f ~/.bashrc ]] && . ~/.bashrc
/home/fb/tmux_bg.sh

Manage tmux Sessions

• List sessions:

tmux ls

• Attach manually:

tmux attach -t fbses

• Detach (leave it running):

Ctrl + b, then d

• Kill session if needed:

tmux kill-session -t fbses

• Check the log:

tail -f /home/fb/autostart/myprogram/run.log

Which Version Should You Use?

• Simple (No Logging) Use this for quick testing or small scripts. It’s good when you just want the script to run and see it immediately, without crash recovery or logs.

• Auto-Attach with Auto-Restart & Logging Best for long-running scripts you want to monitor continuously. Automatically restarts if it crashes and keeps a full log of everything.

• Background Only with Auto-Restart & Logging Ideal for scripts that should run without popping up a tmux window at login. Perfect for headless servers or background tasks, while still restartable and logged.

Tip: All versions create a tmux session under your user. You can use:

tmux ls

to see all sessions, including background-only ones, and:

tmux attach -t fbses

to attach manually whenever needed.

This way you can safely manage scripts without creating multiple sessions on repeated logins.