pong ping

gistfile1.py

# pong.py
import sys
from time import time, sleep

while True:
    print time()
    sys.stdout.flush()
    sleep(1)


# ping.py
import sys

from time import time
from datetime import datetime

last = time()
try:
    while True:
        line = sys.stdin.readline().strip()
        now = time()
        if not line:
            break
        ts = datetime.fromtimestamp(now).strftime('%Y-%m-%d %H:%M:%S')
        deltahere = now - last
        delta = abs(now - float(line))
        
        if deltahere > 1.2:
            print "%s: +%.02f (delta %.02f)" % (ts, deltahere, delta)
        last = now
except KeyboardInterrupt:
    pass

Usage: ssh user@host pong.py | ping.py