`resize` tool without installing `xterm`

resize.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import re
import os
import sys
import tty
import fcntl
import struct
import termios

SIZE_RE = re.compile('\x1b\\[8;(\\d+);(\\d+)t')

def resize():
    fd = sys.stdin.fileno()
    sa = termios.tcgetattr(fd)

    # resize under cbreak mode
    try:
        tty.setcbreak(fd)
        resize_to_fit(fd, sys.stdout.fileno())
    finally:
        termios.tcsetattr(fd, termios.TCSADRAIN, sa)

def resize_window(fd, row, col):
    fcntl.ioctl(fd, termios.TIOCSWINSZ, struct.pack("HH4x", row, col))

def resize_to_fit(stdin, stdout):
    os.write(stdout, b'\x1b[18t')
    ret = SIZE_RE.match(os.read(stdin, 65536).decode('utf-8'))
    resize_window(stdout, int(ret.group(1)), int(ret.group(2)))

if __name__ == '__main__':
    resize()