Greetings!

I am using tmux with zsh.

I use ssh agent forwarding and I ssh to a remote system that is running
tmux. I then detach from that terminal and my SSH_AUTH_SOCK environment
variable becomes "stale".

I would like to have zsh execute something to refresh the SSH_AUTH_SOCK
environment variable when I "tmux attach" to the aforementioned detached
tmux session.

Does anyone know of a way to register a callback or something for zsh so
when a particular command gets run (in my case, tmux attach) my zsh
environment variable can get updated?

Thanks for the help!

-m