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Linux Screen

Just documenting the Linux Screen command.

Install screen first.

yum install screen
dnf install screen
apt install screen
zypper install screen

Start a new screen.

screen -S one
screen -S two
screen -S three

Detach from screen.

Ctrl+a+d

List active screens.

screen -ls 
There is a screen on:
        15575.one   (Detached)
        15581.two   (Detached)
        15593.three (Detached)
1 Socket in /var/run/screen/S-root.

Reattach to an existing screen.

screen -r one
screen -r two
screen -r three

If there’s only one active screen, you can run screen -r without the name.

screen -r

To exit or quit a screen, reattach and run exit.

screen -r three
# exit
[screen is terminating]

Linux Screen

If you don’t have it installed.

yum install screen
apt install screen

Before you run a process, run screen, and detach.

screen
# run the command
ping yahoo.com
# ctrl-a and ctrl-d to detach

To reattach, get a list of screen sessions, and attach to it.

screen -ls
# result is somewhat similar to below
4452.hostname
# attach to it
screen -dr 4452.hostname

To stop, just type exit from the screen terminal.

Chroot A Boot Disk

Here’s a quick way to chroot another boot disk. Attach the rescued boot disk first. Run lsblk and mount. 

lsblk
mount -t xfs -o nouuid /dev/xvdf2 /mnt
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys
mount --bind /dev /mnt/dev
chroot /mnt
cd /mnt
exit

Unmount when done.

umount /mnt/proc
umount /mnt/dev
umount /mnt/sys
umount /mnt