tmux_get_all_windows_as_html.py

import sys
import pyte
import struct
import select
import time
import fcntl
import os
import pty
import subprocess
import termios
from subprocess import PIPE

def get_tmux(t):
    server, client = pty.openpty()
    cols, rows = map(int, subprocess.getoutput("tmux display -p -t 0 '#{window_width}x#{window_height}'").split('x'))
    s = struct.pack('HHHH', rows, cols, 0, 0)
    fcntl.ioctl(client, termios.TIOCSWINSZ, s) 
    subprocess.Popen(
            ['tmux', '-u', '-N', 'attach', '-t', str(t)],
            preexec_fn=os.setsid,
            stdin=client,
            stdout=client,
            stderr=client,
            universal_newlines=True
            )
    time.sleep(0.1) # wait a while else there is no output yet
    output = b''
    start = time.monotonic()
    while True:
        r, _, _ = select.select([ server ], [], [], 0)
        if server not in r or time.monotonic() - start > 1:
            # if there is no output anymore, we exit
            # if we're reading for too, it's probably scrolling continuously so skip that
            break
        output += os.read(server, 1024)
    os.close(client)
    screen = pyte.Screen(cols, rows)
    stream = pyte.Stream(screen)
    stream.feed(output.decode('utf8'))
    return '\n'.join(screen.display)
print('''
<style>
pre {
    background-color: black;
    color: white;
}
</style>
''')

for pane in subprocess.getoutput('tmux -N ls').splitlines():
    paneid = int(pane.split(':')[0])
    pane_title = pane
    pane_content = get_tmux(paneid)
    print(f'<h1>{pane_title}</h1>')
    print(f'<pre>{pane_content}</pre>')