#!/usr/bin/env python

import sys
import time

try:
    bytes_per_chunk, = (int(arg) for arg in sys.argv[1:])
except:
    print >> sys.stderr, '''pull0

usage: pull0 bytes_per_chunk

Repeatedly read stdin for bytes_per_chunk bytes, printing how many were read as
well as 1 second timestamps.'''
    sys.exit(1)

prog = sys.argv[0].split('/')[-1] + ':'

start_time = time.time()
sum = 0
secs = 1
while True:
    chunk = sys.stdin.read(bytes_per_chunk)
    if not chunk: break
    print prog, 'chunk size', len(chunk)
    sum += len(chunk)
    if time.time() - start_time >= secs:
        print prog, 'elapsed', secs, ' average bytes-per-sec', sum // secs
        secs += 1
    sys.stdout.flush()