Having updated a users group with usermod -G <grouplist> <user> in one Byobu split, I was hoping to be able to open a new split and have the permissions take effect there.. rather than having to kill the whole Byobu sessions and login shell.

Is there any way around this?

I realise one can do an exec su -l $USER to effectively re-login.. but I'm wondering if there's a way to get this to take effect for all Byobu splits currently in effect.

1 Answer 1


A process can change its uid and gid, but few processes do this and fewer let the user do this. Neither multiplexer, unfortunately, does either. With screen, apparently one can run a command on all windows using at (see this SU post). There seems to be no direct analogue of at in tmux, solutions usually include parsing the output of other tmux commands (a gist implementing this). Another solution is to synchronize all the windows, and run the command (from this SO post):

Ctrl-B :

setw synchronize-panes on

clear history
  • Interesting set of work arounds there, thanks muru. I'm going to go away and have a play with a few of them.. report back.
    – Ashimema
    Apr 27, 2015 at 19:48

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.