bash: share tmux session between multiple users

# tmux sharing between multiple users on the same machine

* To create the first session

```bash
sudo su
sudo addgroup tmuxg    # create user group for socket
for i in {1..100}; do adduser student$i tmuxg; done

tmux -S /tmp/shareds new -s $USER # create the tmux session on that socket
sudo chgrp tmuxg /tmp/shareds     # change permissions allowing socket access to anyone on the group
chmod 1777 /tmp/shareds
```

* To add a new session from another user (press c-b+s to navigate through sessions)

```bash
YOUR_NAME=Javi
tmux -S /tmp/shareds new -s $YOUR_NAME su $USER
```

* To attach to an existing in read-only mode

```bash
tmux -S /tmp/shareds attach -r
```