Auto-tmux for SSH logins

A solution to the classic problem: you SSH somewhere, start something, and you forgot to run it inside screen or tmux and need to leave (protip: reptyr can save your day in a pinch). This script solves that for you, re-attaching to your session if you later SSH in from someplace else. To use, make the top of your .bashrc look like this:

[ -z "$PS1" ] && return                 # this still comes first
source path/to/bashrc-tmux

# rest of bashrc below...

Note: Also works with zsh.

Behavior

bashrc-tmux won't do anything for local shells. It kicks in when:

1. You are logging in via SSH, and
2. You have tmux installed on the machine.

If both of these things are true, it will create a special tmux session called ssh-$USER (where $USER is your username on the server) and drop you into a throwaway session linked to ssh-$USER. This linkage lets you change windows independently among multiple logins, but all windows themselves are shared.

There are two ways to logout of this configuration. To leave the shell running, you can use the kill-session command [sic!]. This kills the throwaway session and leaves the ssh-$USER session running in the background. When you want to get rid of all sessions, you can just ^D out of all shells in all windows, which will cause tmux to kill the ssh-$USER session and any open throwaways, forcing a logout.

You can also create isolated sessions; see below for details.

Example

Note: this example assumes ^A is the escape key, not tmux's default of ^B.

$ ssh foo               # creates tmux session ssh-spencertipping on foo
foo$ tmux ls            # we are now in tmux
ssh-spencertipping: 1 windows ... (group 0)
ssh-spencertipping-1: 1 windows ... (group 0) (attached)
foo$ du -sh / &         # start something that will take a while
foo$ ^Ak                # kill the throwaway session to logout
$ ssh foo               # ssh-spencertipping already exists, so reuse it
foo$ jobs
[1]+  Running             du -sh / &
foo$ fg                 # reattach to job from last tmux
^C
foo$ ^D                 # exit shell, killing all tmuxen and logging out

Multiple remote tmux sessions

Normally you'll share tabs with existing SSH connections if you log into a server; but you can specify a session suffix if you want to. This will create a new set of shared tabs for anyone logging into that session suffix:

$ ssh -t foo BASHRC_TMUX_SESSION=bar bash
foo$ tmux ls
ssh-spencertipping-bar: 1 windows ... (group 0)
ssh-spencertipping-bar-1: 1 windows ... (group 0) (attached)

xpra extension

xpra is to X11 what tmux is to ssh, and you can source bashrc-xpra to enable it in similar situations. You can then temporarily attach to the remote display by saying this:

$ xpra attach ssh:remote-system:100