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I want to create a crontab entry so that it starts screen, starts a gameserver and detaches. This is for in case the server is rebooted and I want it to automatically start this for me.

0 0 0 0 0 (command)

should run upon startup.

It runs a shell file located at ~/cube/server.sh

Victor
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5 Answers5

24

Something like this should work. This example spawns a screen and runs "top":

screen -d -m top

In your crontab, as indicated, you'd want to do something like this:

@reboot /usr/bin/screen -dmS gameserver-screen /opt/mycoolgame/bin/gameserver

Of course, if the game server requires a "normal" environment set, you can get closer by:

@reboot (. ~/.profile; /usr/bin/screen -dmS gameserver-screen /opt/mycoolgame/bin/gameserver)
Corey S.
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5

This should be sufficient...run

$ crontab -e

Then enter:

@reboot screen -dmS Victor
atx
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4

Just for completeness' sake, it's also possible to use tmux for the purpose instead of screen (see this link for a comparison):

@reboot tmux new-session -d -s yourNameOfTheSession "your command to run"
Petr
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2

It needs to be noted that simply using screen -dmS SessionNameHere someCommand is NOT enough. In many envs (IE: Ubuntu 18.x) you also have to give the tmp dir or you cant re-attach to the running screen, you wont even be able to list them. The CORRECT way to run screen in crontab is like this:

 * * * * * export SCREENDIR=~/tmp ; screen -dmS SessionNameHEre SomeCommand

So if you cant connect to a session started by cron (I had this issue with Ubuntu 18), find out what screen is using for a tmp dir, and put that in the crontab entry. You can do that with "echo $SCREENDIR"

user944364
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0

I had a similar situation, but due to other unreasonable restrictions, I could not use crontab. I actually had inittab call screen. ( replaced some names to obscure information):

XXX:5:respawn:/bin/su - useraccount -c "screen -D -m -c /home/xxxxxx/file.screenrc"

In 'file.screenrc' is where I setup a few options:

sessionname obscuresessionname
multiuser on
cd
screen /home/xxxxxxx/programtostart

This way it started on boot, and if the program died or screen closed it would re spawn. It may not have been considered conventional, but I had to work a round a few odd environment requirements. If we needed to take it down though, we would have to comment that line out, and kill session. Then when ready to bring it back up, uncomment, and init q.

mangloide
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