ssh-tmux

#!/bin/sh
set -eu

if ! which tmux > /dev/null; then
    echo>&2 "$(basename "$0"): tmux: command not found"
    exit 3
fi

usage() {
    cat >&2 <<EOM
Usage: $(basename "$0") SSH_HOST...

SSH to each SSH_HOST in separate tmux panes.

EOM

}

tmux_cmd() {
        tmux send-keys -t $session "$*
"
}
tmux_ssh() {
    tmux_cmd "ssh '$1'"
}

if [ $# -lt 1 ]; then
    usage
    exit 1
fi

session=$(mktemp -u ssh-XXX)
tmux new-session -d -s $session

# should attach to session even if we fail somewhere
trap "tmux attach -t $session" EXIT

first_host="$1"
shift

tmux_ssh "$first_host"

for host in $*; do
    tmux split-window -t $session -v
    tmux select-layout -t $session even-vertical
    tmux_ssh "$host"
done