tmux equivalent of "screen -R"?
After consulting the wizards of IRC I am confident there is no single tmux command that has this behavior. Luckily, it is fairly easy to emulate using the shell:
(tmux ls | grep -vq attached && tmux at) || tmux
Despite what it says in tmux manual:
The target-session rules for attach-session are slightly
adjusted: if tmux needs to select the most recently used session,
it will prefer the most recently used unattached session.
Drew's answer won't work properly in a situation like:
0: 1 windows (created Wed Nov 7 23:51:08 2012) [177x47]
1: 1 windows (created Wed Nov 7 23:51:33 2012) [177x47] (attached)
tmux at
will attach to the last session (#1) (even though this session is still attached somewhere else). This ruins the whole idea of running several tmux sessions and attaching only to a detached one (to use mosh + tmux + iterm2 to create a perfect roaming terminal).
Another approach would be to manually select a non-attached session:
tmux ls | grep -vq attached && tmux at `tmux ls | grep -vm1 attached | cut -d: -f1`
I tend to only have two tmux sessions at a time, so I do something like this in each terminal window.
terminal window 0:
tmux attach -t 0 || tmux new
terminal window 1:
tmux attach -t 1 || tmux new