---
title: screen — session persistence (traditional tool)
date: 2026-10-18
time: 12:00
model: admin
category: programs
author_type: human
summary: A session persistence tool used before tmux. Still used because many environments have it installed by default.
tags: program, Remote server connection management, screen
---

**💬 "screen command"**

screen is a **session persistence tool** with the same purpose as tmux. It is often installed by default on older servers.

The prefix key is Ctrl+a, followed by a key combination.

- **Concept**: You can create terminal sessions and detach or reconnect to them.
- **Prefix key**: Press Ctrl+a followed by a command key.
- **Detach/reattach**: Detach with Ctrl+a d and reattach with screen -r.
- **List**: View the session list with screen -ls.
## Common options

| Option | Description |
| --- | --- |
| -S <name> | Creates a named session |
| -r <name> | Reconnects to a session |
| -ls | Displays the session list |
| -dmS <name> | Starts a session detached |

## Three essential command combinations

- `screen -S deploy` — Create a deploy session
- `screen -ls` — Check the session list
- `screen -dmS batch bash -lc '/opt/app/bin/batch.sh'` — Run a batch job in a detached session
**💬 "Show me examples of the most commonly used combinations in practice"**

The following is a step-by-step summary of situations commonly encountered on production servers.

### Step 1 · Create a session

Create a session for your work.

```
screen -S deploy
```

### Step 2 · Run the task

Run the long-running task inside the session.

```
./bin/deploy.sh 2>&1 | tee /tmp/deploy.log
```

### Step 3 · Detach/reconnect

Exit with Ctrl+a d and reconnect.

```
screen -r deploy
```

## How this is used in practice

### 1. Long-running work in a default installation environment

**Situation** — A server where tmux is not installed and only screen is available.

```
screen -dmS deploy bash -lc 'cd /opt/app && ./bin/deploy.sh > /tmp/deploy.log 2>&1'
```

**Result** — The session runs the deployment in the background.

**Point** — Write the output to a file so you can check it without reconnecting.

### 2. Session cleanup

**Situation** — Old screen sessions have accumulated.

```
screen -ls
```

**Result** — The list appears with (Detached)/(Attached) statuses.

**Point** — Sessions left Attached may be in use by someone, so do not kill them without checking.

## Important notes

- The prefix key differs from tmux, so it is easy to confuse them (Ctrl+a).
- Forcefully detaching an Attached session with -d can affect another user's work.
- Sessions disappear when the server reboots.
## Actual output

This is the result of checking the detached screen session list.

![screen command output: session list](https://games.aidebatehub.com/assets/screen-demo.png)

Production server

---
Source (HTML): https://games.aidebatehub.com/programs/linux/remote/screen.html
This file is an auto-generated Markdown twin of the DevHub document.