Example screen commands: a plurality of terminal session management

GNU Screen is a terminal multiplexer (window manager). As the name suggests, Screen may be multiplexed between a plurality of physical terminal interactive shell, so we can perform different tasks at each terminal session. All sessions are completely independent of the Screen run the program. Therefore, even if the session closed unexpectedly or disconnected, running in the Screen session or process will continue to run. For example, when using SSH upgrade Ubuntu server, the screencommand will continue to run the upgrade process, just in case SSH session is terminated for any reason.

GNU Screen allows us to easily create multiple Screen session and switch between different sessions, copy text between sessions, at any time on or even out of the session and so on. It is one of the important commands for each Linux administrators should learn and use when necessary line tool. In this brief guide, we will see the screenbasic usage of commands and examples in Linux.

Install GNU Screen

GNU Screen in most Linux operating system's default repository are available.

To install GNU Screen on Arch Linux, run:

$ sudo pacman -S screen
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In Debian, Ubuntu, Linux Mint on:

$ sudo apt-get install screen
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On Fedora:

$ sudo dnf install screen
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On RHEL, CentOS:

$ sudo yum install screen
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On SUSE / openSUSE:

$ sudo zypper install screen
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Let's continue with the screenexample command.

A plurality of terminal session management command examples Screen

In the Screen default prefix shortcuts for all commands is Ctrl + a. When you use Screen, you often need to use this shortcut. So, remember this keyboard shortcut.

Creating a new Screen Session

Let's create a new Screen session and connect to it. To do this, type the following command in the terminal:

screen
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Now, run any program or process in this session, even if you disconnect from this session, process or running program will continue to run.

Released from the Screen session

Out from the screen session, press Ctrl + aand d. You do not need to press the two key combination. First press Ctrl + aand then press d. From the conversation off, you will see something like the following output.

[detached from 29149.pts-0.sk]
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Here 29149is the Screen ID, pts-0.skis the name of a screen session. You can use the Screen ID or session name corresponding to the company, out of the screen and terminates the session.

Create a named session

You can also create a Screen session with any custom name of your choice, instead of the default user name, as shown below.

screen -S ostechnix
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The above command will create a file named xxxxx.ostechnixnew Screen session and immediately connect to it. Out from the current session, press Ctrl + aand press d.

When you want to find out what processes are running on which sessions, naming the session would be useful. For example, when the system is disposed in the session LAMP, you can simply be named as follows.

screen -S lampstack
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Created out of session

Sometimes, you may want to create a conversation, but do not want to automatically connect to the session. In this case, run the following command to create a file named senthilhas been out of the session:

screen -S senthil -d -m
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It can be shortened to:

screen -dmS senthil
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The above command will create a named senthilsession, but will not connect to it.

Lists the screen session

To list all running sessions (or even on the off), run:

screen -ls
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Sample output:

There are screens on:
    29700.senthil   (Detached)
    29415.ostechnix (Detached)
    29149.pts-0.sk  (Detached)
3 Sockets in /run/screens/S-sk.
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As you can see, I have three running sessions and all sessions are off.

Even on Screen Session

If you want to connect to the session, for example 29415.ostechnix, simply run:

screen -r 29415.ostechnix
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or:

screen -r ostechnix
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Or Screen ID:

screen -r 29415
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To verify that we connect to the above-mentioned session, just list the open session and check.

screen -ls
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Sample output:

There are screens on:
        29700.senthil   (Detached)
        29415.ostechnix (Attached)
        29149.pts-0.sk  (Detached)
3 Sockets in /run/screens/S-sk.
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As you can see in the above output, we now connect to the 29415.ostechnixsession. To exit the current session, press ctrl + a d.

To create a nested conversation

When we run the screencommand, it creates a session for us. However, we can create nested session (a session within the session).

First, create a new session or even open session. Then I will create a file called nestednew session.

screen -S nested
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Now, in the session press Ctrl + aand ccreate another session. Just repeat this operation can create any number of nested Screen session. Each session will be assigned a number. Number from the 0start.

You can press Ctrl + nto move to the next session, and then press Ctrl + pto move to the previous session.

The following are important session management nested list of keyboard shortcuts.

Ctrl + a " - List all sessions
Ctrl + a 0 - Switch to the session number 0
Ctrl + a n - switching to the next session
Ctrl + a p - switching to the previous session
Ctrl + a S - current region is divided horizontally into two regions
Ctrl + a l - The current region vertically divided into two regions
Ctrl + a Q - close all sessions except the current session
Ctrl + a X - Close the current session
Ctrl + a \ - terminate all sessions and terminate Screen
Ctrl + a ?- Displays key bindings. To exit, press Enter

Lock Session

Screen has an option to lock the session. To do this, press Ctrl + aand x. Enter your password to lock Linux.

Screen used by sk <sk> on ubuntuserver.
Password:
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Recording session

You may want to record all the contents Screen session. To do this, simply press Ctrl + aand Hcan be.

Or, you can use the -Lparameters to start a new session to enable logging.

screen -L
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From now on, you do all the activities in the session will be recorded and stored in a $HOMEdirectory named screenlog.xfile. Here xis a number.

You can use the catcommand or any text viewer to view the contents of the log file.

Screen recording session

Screen session termination

If you no longer need to session, just kill it. To kill called senthildisengagement session:

screen -r senthil -X quit
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or:

screen -X -S senthil quit
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or:

screen -X -S 29415 quit
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If there is no open session, you will see the following output:

$ screen -ls
No Sockets found in /run/screens/S-sk.
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For more details, please refer to the man page:

$ man screen
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There is also a similar command line utility called Tmux, it performs the same work with GNU Screen. For more information, please refer to the following guidelines.

Tmux command examples: managing a plurality of terminal sessions

Resources

GNU Screen Home

via: www.ostechnix.com/screen-comm…

Author: SK topics: lujun9972 Translator: wxy proofread: wxy

This article from the LCTT original compiler, Linux China is proud

Reproduced in: https: //juejin.im/post/5cffb475e51d45775f516a48