I would like to send a command to a screen session and if possible get the output.My attempt at sending a command to a screen session is as I found on this website and lots of others, but it doesn't seem to work:root@server [~]# screen -X script -a -c 'ls -l' /tmp/command.log && cat /tmp/command.logcat: /tmp/command.log: No such file or directoryroot@server [~]# Note there is only 1 Screen session running, so I have omitted -S and -p (tried it with those too and no effect). For example:root@server [~]# screen -p 0 -X stuff script -a -c 'ls -l' /tmp/command.log && cat /tmp/command.logcat: /tmp/command.log: No such file or directory
Trouble sending command to detached Screen session
gnu screen
First, read sending text input to a detached screen. You do need -p to direct the input to the right window. Also, the command won't be executed until you stuff a newline (CR or LF, the interactive shell running inside screen accepts both). That's:screen -p 0 -X stuff script -a -c 'ls -l' /tmp/command.log$(printf \\r) &&cat /tmp/command.logThere's a second problem, which is that the screen -X stuff  command completes as soon as the input has been fed into the screen session. But it takes a little time to run that script command. When cat /tmp/command.log executes, it's likely that script hasn't finished; it might not even have started yet.You'll need to make the command running inside screen produce some kind of notification. For example, it could signal back that it's finished, assuming that the shell within Screen is running on the same machine as Screen.sh -c '  sleep 99999999 &  screen -p 0 -X stuff \script -a -c \ls -l\ /tmp/command.log; kill -USR1 $!  wait  cat /tmp/command.log'