Use tiled view correctly

mssh.rb

#!/usr/bin/env ruby

require 'digest'

hosts = ARGV.to_a
hosts = $<.each_line.map(&:chomp) if hosts.empty?
hosts.uniq!

def system! *args
  raise "Cannot exec #{args}" unless system(*args.flatten)
end

session = "mssh-#{Digest::SHA1.hexdigest(hosts.sort.join('-'))}"
unless `tmux list-session`.include?("#{session}: ")
  # new session
  system! ['tmux', 'new-session', '-d', '-s', session]
  system! ['tmux', 'set-option', '-t', session, 'synchronize-panes', 'off']

  hosts.each do |host|
    system! ['tmux', 'send-keys', '-t', session, "exec ssh #{host}", 'C-m']
    if host != hosts.last
      system! ['tmux', 'split-window', '-t', session]
    end
    system! ['tmux', 'select-layout', '-t', session, 'tiled']
  end
  system! ['tmux', 'set-option', '-t', session, 'synchronize-panes', 'on']
end

# attach
system! ['tmux', 'attach-session', '-t', session]