Grab the last output from tmux

tmux-last-output

#!/usr/bin/env ruby
#
# The maximum length of a multiplexed packet is 32,768 bytes
#
# Unfortunately this works best (only works) if you have an uncommon character
# in your prompt to split on. I use "»".

FILE = '/tmp/tmux-pane'
PROMPT = '»'

system "tmux capture-pane -S -32768 -p > #{FILE}"

print File.read(FILE).
  split(PROMPT)[-2].
  lines[1..-2].
  join