Tmux Interactive Processes

Tmux Interactive Processes

Use tmux when a command needs to keep running, accept later input, show ongoing output, or remain available for human attachment.

Prefer tmux over raw background shell patterns because the process stays visible, inspectable, attachable, and controllable.

Avoid Background Bash

Do not use these patterns for long-running or interactive work:

command &
nohup command &
command > log.txt 2>&1 &
disown
tail -f log.txt

Use normal shell execution only when the command runs to completion and prints final output.

Session Names

Use stable, descriptive names:

agent-<repo-or-project>-<purpose>

Examples:

agent-myapp-dev
agent-myapp-tests
agent-myapp-debug
agent-myapp-repl

Check existing sessions before creating a new one:

tmux list-sessions

Reuse a matching session when appropriate.

Start Commands

Create a detached session from the current working directory:

tmux new-session -d -s agent-myapp-dev -c "$PWD" 'npm run dev'

For commands with tricky quoting, start a shell first:

tmux new-session -d -s agent-myapp-dev -c "$PWD" bash
tmux send-keys -t agent-myapp-dev 'npm run dev' C-m

Inspect the pane after startup before claiming success.

Inspect Output

Capture recent output:

tmux capture-pane -pt agent-myapp-dev -S -200

Capture more history:

tmux capture-pane -pt agent-myapp-dev -S -1000

Use capture-pane to verify readiness, failures, prompts, and current state.

Send Input

Send text followed by Enter:

tmux send-keys -t agent-myapp-dev 'help' C-m

Send control keys:

tmux send-keys -t agent-myapp-dev C-c

Use send-keys for REPLs, debuggers, prompts, and graceful shutdown.

User Attachment

When useful, report the session name and attach command:

tmux attach -t agent-myapp-dev

Stop Sessions

Prefer graceful shutdown first:

tmux send-keys -t agent-myapp-dev C-c

Inspect after shutdown:

tmux capture-pane -pt agent-myapp-dev -S -100

Remove the session only when it is no longer needed:

tmux kill-session -t agent-myapp-dev

Checklist

1. Run tmux list-sessions.
2. Reuse a matching session or create a detached session.
3. Capture pane output after startup.
4. Report the session name to the user.
5. Inspect with capture-pane before making claims about state.
6. Interact with send-keys when input is needed.
7. Clean up sessions that are no longer needed.

Decision Rule

If a command is expected to run continuously, wait for input, display ongoing output, or require later interaction, use tmux.

If a command runs to completion and only prints final output, use normal shell execution.