This is so much more complicated! When using byobu I use F3 and F4 to cycle to previous and next window. I can't understand why they think that by default I want all of the viewers to switch at once.

I think that the main issue that you're having is that 'active window' is an attribute of a session, and not of the client. If 'active window' were specific to a client, then two clients could switch windows independently while connected to the same session.

You could petition for an option to the `attach-session` command that automatically creates a new session grouped to the session that you're 'attaching' to. IIRC, you can't attach two 'clients' to the same (GNU) screen session unless you use the -x option, so it's not like it's the 'default' behaviour for screen either.

Edit:

I wasn't thinking, but `new-session` will automatically connect to the new session you created, so there is no need for an option to `attach-session`. So when you want to connect a second client, just:

  # find the session you want
  $ tmux list-sessions

  # create a grouped session
  $ tmux new-session -t SESSION_ID

Edit 2:

  | This is so much more complicated!

Depends. If you're using byobu, then you're already attempting to abstract away a bunch of the complexity of GNU screen, so it's not like you would find less complexity if you dove into the screen internals. It's also this design that makes it easier to do complex things that screen can't do with its windows.

  | When using byobu I use F3 and F4 to cycle to
  | previous and next window.

Maybe you're misunderstanding. You still use the same tmux bindings to switch windows, it's just the setting up of the session that requires slightly more work when connecting a second client.

Since I use byobu I neither know nor care what is going on under the hood. I use 4 keystrokes - F2 to start a new shell, F3 to cycle back, F4 to cycle forwards and ctrl-F5 to reconnect sockets (GPG agent, DBUS etc).

I did switch it from screen to tmux because tmux definitely works better for other things and seems more responsive when there is lots of output. By default screen did let each client view independent of any other.

I don't see how to automate getting the behaviour I want (independent client views) as typing commands and feeding them into tmux would be a huge pain (especially as byobu is already doing that).

It really depends on what your workflow is. If you only ever have a single tmux session, then you could write a quick script that starts a session if it doesn't exist, but if it does, automatically creates a mirrored session and connects to it. In this workflow, you can assume which session you want to group with, but if you work with multiple sessions, then there is no way to automatically do this. E.g., you could run something like:

  $ tmux.sh session-name

which would create the session the first time, and create a grouped session, the second time.

Edit:

I've created a little script for this: https://github.com/bsandrow/tmux.sh

I created a byobu ticket to cover this issue as it is what ultimately starts/connects tmux pointing to this thread. Thanks for the solution. https://bugs.launchpad.net/byobu/+bug/1168734

Having the viewers switch by default is useful for demos, when you are showing something to someone. And it's the simplest behaviour for their data structure. So I can see some logic to why they designed it that way.

I'm glad you raised this issue because I've only recently moved to tmux and would have been stung by it.

Could you abstract it away behind a shell alias? I used this:

   alias tmuxc='tmux new-session -t 0'

I don't know since I am using byobu to front end all this, and it is what runs tmux/screen under the hood in the end.