sshping

#!/usr/bin/env python3

import subprocess
import os
import sys
import time

ssh_host = sys.argv[1]

stdin_pipe = os.pipe()
stdout_pipe = os.pipe()

proc = subprocess.Popen(['ssh', ssh_host, 'cat'],
                        stdin=stdin_pipe[0], stdout=stdout_pipe[1])
os.close(stdin_pipe[0])
os.close(stdout_pipe[1])

try:
    while True:
        start = time.time()
        os.write(stdin_pipe[1], b'z')
        assert os.read(stdout_pipe[0], 1) == b'z'
        end = time.time()

        print('{0:.3f} ms'.format((end - start) * 1000))
        time.sleep(1)

except KeyboardInterrupt:
    pass

finally:
    os.close(stdin_pipe[1])
    os.close(stdout_pipe[0])
    proc.wait()