sshping - create ssh connect and measure character typing latency (send single character until it appears)

sshping.py

#!/usr/bin/env python

# You may use this under an MIT license

from time import time, sleep
from signal import signal, SIGINT
import subprocess
import sys

def write_read(p):
    a = time()
    p.stdin.write(b"z")
    assert p.stdout.read(1) == b"z"
    return round(1000 * (time() - a), 1)


host = sys.argv[1]
p = subprocess.Popen(['ssh', host, 'cat'],
                     stdin=subprocess.PIPE, stdout=subprocess.PIPE, bufsize=0)

times = []
def finish(*args):
    avg1 = round(sum(times) / len(times), 1)
    avg2 = round(sum(times[1:]) / (len(times)-1), 1)
    print("\nAverage (including first):     %s ms" % avg1)
    print("Average (not including first): %s ms" % avg2)
    sys.exit(0)
signal(SIGINT, finish)

first = True
while True:
    ms = write_read(p)
    times.append(ms)
    if len(times) == 0:
        note = " (including connect time)"
    else:
        note = ""
    print("1 char to/from %s: %s ms%s" % (host, ms, note))
    sleep(1)