Start tmux and ssh to multiple hosts with synchronized input

ssh-multi.sh

#! /bin/bash

if [ -z "$1" ]; then
    echo "please supply at least one server to connect to" >&2
    exit 1
fi

target=multi-ssh-$$

if [ -z "$TMUX" ]; then
    tmux new-session -d -s "$target"
fi

if [ -n "$(type -p autossh 2> /dev/null)" ]; then
    ssh="AUTOSSH_GATETIME=${AUTOSSH_GATETIME:-0} autossh"
else
    ssh="ssh"
fi

tmux new-window -n "$target" "$ssh $1"
shift

for host in "$@"; do
    tmux split-window -t ":$target" -h "$ssh $host"
    tmux select-layout -t ":$target" tiled #> /dev/null
done

tmux select-pane -t ":$target"
tmux set-window-option -t ":$target" synchronize-panes on #>/dev/null

if [ -z "$TMUX" ]; then
    tmux attach-session -d -t ":$target"
fi