Make tmux plugin refresh tmux global environments automatically.

[delphij]

This is handy for tmux users who work in interactive mode. By default, tmux would pass through e.g. X11, SSH agent, etc. via global environment.

[delphij]

Hi, @robbyrussell are you looking for someone to do the testing, or would like some instructions?

To test:

• Enable the 'tmux' plugin in ~/.zshrc

ssh -A to the system, then run 'tmux'.

env | grep SSH_AUTH_SOCK

Detach the session (Ctrl+B, D), logout, then repeat ssh -A, tmux

Hit enter (which makes sure that zsh have a new prompt)

env | grep SSH_AUTH_SOCK

The result should be different. ssh'ing to other hosts would be relayed to user's workstation for SSH agent authentication.

[xals]

Hello @delphij,
You may use the preexec hook instead of precmd so you would not have to press enter just before running a command. Anyway, I don't know how it behaves on variable substitution, to be tested, I think.

[delphij]

Good point! I have updated my tree and it worked.

[khsing]

I have tested this feature, truly helped me while I am connected throughtmux, very good one.

ps. second tmux is attach to the pervious session, not new one.

➜  ~ env | grep SSH_AUTH # first ssh connection and tmux new session 
SSH_AUTH_SOCK=/tmp/ssh-dxCaf0fmj8/agent.22865
➜  ~ env | grep SSH_AUTH  # second ssh connection and tmux attach back
SSH_AUTH_SOCK=/tmp/ssh-xtau3V7aPt/agent.23157
➜  ~ 

Thank you very much.

[MikeDacre]

Personally, I think this PR should be merged, the functionality is super helpful and can be easily toggled on/off by the user.

@xals I think you were asking about how changing variables that are also set in the tmux update-environment command, it is true that with this plugin those commands would be automatically overridden, and any variables set from them (e.g. i=$DISPLAY) will not be updated by the preexec hook.

@delphij I would suggest also adding tmux ls >/dev/null 2>/dev/null to your test on line 106, because otherwise if someone SSHs into another machine from within tmux, and that machine has this plugin installed, it will run anyway as both variables will be set, so then the user will get tmux errors on every prompt/command. I would suggest changing the test to:

[[ -n "$TMUX"  && "$ZSH_TMUX_AUTOREFRESH" == "true" ]] && tmux ls >/dev/null 2>/dev/null

[delphij]

I've rebased my changes over the latest version of the plugin.