Keep GNU screen window open after program terminates

Enable the altscreen option in ~/.screenrc.

Full-screen programs use a terminal feature called "alternate screen", which has a separate screen buffer and (often) minor behavior changes to adapt to such interfaces. The program enters the 'alternate' screen when started, and goes back to 'normal' when exiting.

Since Screen itself acts as a terminal emulator, it has to emulate the alt-screen feature as well. All other terminal emulators enable this feature by default, but Screen has it hidden behind the altscreen option for some historical reasons.

CtrlS is the "Pause transmission" (XOFF) flow control character. Usually it's handled by the tty driver, or in this case Screen. Its opposite is XON, or CtrlQ.

When you launch Emacs, it normally takes over most of the special characters (not just flow control, but also the usual CtrlC "Interrupt", for example).

• Use C-a :flow off to disable flow-control for this Screen window.

  Confirm with C-a :info (look for -flow in the pop-up).

• If it doesn't help, try stty -ixon or stty stop undef.

  (You can do it from a separate window using stty -f /dev/tty1 or stty </dev/tty1.)

On my system (Linux), Screen does notice when flow control is disabled for the tty. Your OS might have some limitations, though.