How to enable logging in screen session

http://unix.stackexchange.com/questions/240796/gnu-screen-how-to-enable-or-disable-logging-while-screen-is-already-attached

To enable logging on the current window of a screen session, press Ctrl+AH (uppercase H, Shift+H if you prefer).

That actually toggles the logging state (so if the windows was being logged beforehand, it is now no longer logged).

That's the log command in screen, so you can also do Ctrl+A: and enter log (or log on to turn it on instead of toggling the state), or run screen -X log on within the shell running in the current window.

To enable logging on all windows, use the at command to apply that to all windows:

screen -X at '#' log on Or press, Ctrl+A: and enter at \# log on.

For more details, see:

info -f screen --index-search=at info -f screen --index-search=log