Multiple ssh session (It works even the current terminal is already in tmux)

ssh-multi.sh

#!/bin/bash
# ****MOVE TO*** https://github.com/greymd/tmssh

# ssh-multi
# yasuhiro.yamada
# Based on http://linuxpixies.blogspot.jp/2011/06/tmux-copy-mode-and-how-to-control.html
# and https://gist.github.com/dmytro/3984680

# a script to ssh multiple servers over multiple tmux panes

starttmux() {
    if [ -z "$HOSTS" ]; then
        echo -n "Please provide of list of hosts separated by spaces [ENTER]: "
        read HOSTS
    fi
    local hosts=( $HOSTS )
    tmux new-window -n "$WIN_NAME"
    for i in "${hosts[@]}"; do
        tmux split-window  -t "$WIN_NAME" -h  "ssh $i"
    done
    tmux kill-pane -t "${WIN_NAME}.0"
    tmux select-pane -t "${WIN_NAME}.0"
    tmux select-layout -t "${WIN_NAME}" tiled > /dev/null
    tmux set-window-option -t "${WIN_NAME}" synchronize-panes on > /dev/null
}

WIN_NAME="$1-$$"
HOSTS=${HOSTS:=$*}

starttmux