A python script to emulate the bandwidth of a modem at certain speed.

modem-speed.py

#!/usr/bin/python -u

# Use: modem-speed.py [baud, default 1200]
import sys
from time import sleep

baud = len(sys.argv) > 1 and int(sys.argv[1]) or 1200
cps = baud/10.0 # 10 baud per octet at 8n1

while True:
  c = sys.stdin.read(1)
  if c == "":
    break
  sys.stdout.write(c)
  sleep(1.0/cps)