Cron – how to use screen with crontab

crongnu-screen

I have a screen task running with node (nodemon)
I would like to restart nodemon at midinght every day

What I do manually is under SSH

screen -r myscreen
I TYPE "rs" manually
I type CTRL+A+D to
detach the screen

Is there a way to automatize that with CRON?

Best Answer

why do you need "screen" in automated tasks ? if you add your task to /etc/crontab (or the personal crontab with "crontab -e" command) and you have the local MTA configured properly to send status mails to your admin, you should be able to achieve that repetitive automatic task including any output+errors without screen at all.

if you need to start scripts or tasks in the background having them run even if the parent shell ends you could look up "nohup" as in "man nohup". if im not wrong it can run your programm/script even when you end your shell/session.

Related Solutions

Linux – How to reconnect to a disconnected ssh session

UPDATE: For an actual answer see zero_r's answer below

This isn't an answer, but a workaround. Use screen.

When you first log in, run screen. You get another shell, run commands in that. If you're disconnected, the screen process keeps the terminal alive so that your shell and the processes it is running don't fall over. When you reconnect, run 'screen -r' to resume.

There's a bunch more to configuring and using screen, but the above should workaround your problem.

Ssh – How to launch a screen session with a command over ssh on a remote server from the desktop

Try using the -t option to ssh

ssh -t root@my.machine screen "tail -f /var/log/messages"

From man ssh

-t      Force pseudo-tty allocation.  This can be used to execute arbi-
        trary screen-based programs on a remote machine, which can be
        very useful, e.g., when implementing menu services.  Multiple -t
        options force tty allocation, even if ssh has no local tty.

Best Answer

Related Solutions

Linux – How to reconnect to a disconnected ssh session

Ssh – How to launch a screen session with a command over ssh on a remote server from the desktop

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