quick script that automates scraping online ping tools and graphs the results (see comment below)

pingtimes.py

#!/usr/bin/env python
# Copyright (c) 2009 Thomas Shanks and the Georgia Institute of Technology
# Licensed under an MIT-Style (like BSD-style) free-software license; see complete notice at end.
#
# This script emulates the process described in Savage (et al.)'s IEEE Micro article 
# "Detour: Informed Internet Routing and Transport" at http://doi.ieeecomputersociety.org/10.1109/40.748796 .

import os
from urlparse import urlparse
import re
import socket
import numpy
import csv
import Gnuplot

URLs = open('URLs', "r").readlines()
URLinfos = []

for aURL in URLs:
     URLinfos.append((aURL.rstrip('\n'),  socket.gethostbyname(urlparse(aURL).netloc)))        
print URLinfos

N =  15 #If they didn't take so long to run, this would be len(URLs). Instead, put the number of servers to run.
PingTimes = numpy.zeros((N, N), dtype=float)

for pingto in xrange(0, N):
    for pingfrom in xrange(0,  N):
        if pingfrom == pingto:
            continue
        response = os.popen("lynx -dump " + URLinfos[pingfrom][0] + URLinfos[pingto][1]).readlines()
        #print response
        avg=0
        for line in response:
            linepingtimes = re.findall('[0-9]{1,3}[.]?[0-9]{1,3} ?ms',  line)
            linesum = 0
            for apingtime in linepingtimes:
                linesum += float(apingtime.rstrip('ms'))
            if linesum > 0:
                avg = linesum / len(linepingtimes)
        if avg != 0:
            PingTimes[pingfrom][pingto] = avg
            print pingfrom,  " to ",  pingto,  " time ",  avg 

fileforcsv = open('pingtimesout.csv', 'w')
csvout = csv.writer(fileforcsv)
for row in PingTimes:
    csvout.writerow(row)
    print row
fileforcsv.close()

DetourTimes = numpy.zeros((N, N), dtype=float)
scatterplot = []

for pingto in xrange(0, N):
    for pingfrom in xrange(0,  N):
        detourtime = 10000 #huge
        for pingthrough in xrange(0,  N):
            if (pingto == pingfrom) or (pingthrough == pingfrom) or (pingthrough == pingto) or  (PingTimes[pingfrom][pingthrough] == 0) or (PingTimes[pingthrough][pingto] == 0):
                continue
                
            thistime =  PingTimes[pingfrom][pingthrough] + PingTimes[pingthrough][pingto]
            if (thistime < detourtime):
                print "Better detour: ",  pingfrom, " through ",  pingthrough,  " to ",  pingto , " time ", thistime,  " better than ",  detourtime
                detourtime = thistime
        
        if (detourtime < 10000) and (detourtime > 0):
            DetourTimes[pingfrom][pingto] = detourtime
            scatterplot.append(PingTimes[pingfrom][pingto]/DetourTimes[pingfrom][pingto])

fileforcsv = open('detourtimesout.csv', 'w')
csvout = csv.writer(fileforcsv)
print "\ndetour\n"
for row in DetourTimes:
    csvout.writerow(row)
    print row,  ' '
fileforcsv.close()


print "\nscatter\n"
scatterplot.sort(reverse=True)
xaxis = numpy.linspace(0,  1,  len(scatterplot))

outfile = open('scatterplotpoints', 'w')
for index in xrange(0, len(scatterplot)):
    outfile.write(`xaxis[index] `+ ' '+`scatterplot[index]`+'\n' )
    print `scatterplot[index]`+ ' '
outfile.close()

gp = Gnuplot.Gnuplot(persist = 1)
gp('set terminal png')
gp('set output "detour-traceroute-inquiry-output.png"')
gp(' set xlabel "Fraction of paths measured"')
gp(' set ylabel "Ratio of default-route latency to alternate-route latency"')
gp("plot 'scatterplotpoints'")

#Copyright (c) 2009 Thomas Shanks and the Georgia Institute of Technology
#
#Permission is hereby granted, free of charge, to any person
#obtaining a copy of this software and associated documentation
#files (the "Software"), to deal in the Software without
#restriction, including without limitation the rights to use,
#copy, modify, merge, publish, distribute, sublicense, and/or sell
#copies of the Software, and to permit persons to whom the
#Software is furnished to do so, subject to the following
#conditions:
#
#The above copyright notice and this permission notice shall be
#included in all copies or substantial portions of the Software.
#
#THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
#EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
#OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
#NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
#HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
#WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
#FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
#OTHER DEALINGS IN THE SOFTWARE.

The assignment was specifically to use these online ping tools to estimate the efficacy (albeit inaccurately, as ping RTT doesn't equal TCP RTT) of using detour routing vs the status quo. I decided to automate the process.

I put it here as a programming example for someone. It's no work of art; it's just a quick script automating some web scraping of web-based ping tools.