tmux multiple session
$tmux - create new session (name 0)
$ echo "session 0"
$ Ctrl-b d - detach
$ tmux - create new session (name 1)
$ echo "session 1"
$ Ctrl-b d - detach
$ tmux new -s sample - new session (name sample)
$ echo sample
$ Ctrl-b d - detach
$ tmux ls
0: 1 windows (created Wed Jul 20 11:51:58 2016) [101x50]
1: 1 windows (created Wed Jul 20 11:52:02 2016) [101x50]
sample: 1 windows (created Wed Jul 20 11:54:53 2016) [101x50]
$ tmux a -t 1 - attach to session 1
$ Ctrl-b d
$ tmux a -t sample - attach to session sample
$ Ctrl-b s - list sessions and select another one
$ Ctrl-b $ - rename current session
$ tmux kill-session -t session-name - or just exit the window with Ctrl-d