#! /usr/bin/env python

############################################################
#
#    The Silent Page Counter v 0.3
#
#   (c) 1998 Cristian Tibirna
#
# This is *the first* CGI script I wrote in python
# In fact, this can really be seen in here
#
# It was written and tested in Linux only. It is Unix-specific
#
# Usage: * just install it in your /cgi-bin directory and chmod it to 755
#        * then create a data directory somewhere in your account
#          and chmod it to 777
#        * write the name in the appropriate place below
#        * then replace your selected links to files in your html documents
#           with: http://your_server/your_cgi_dir/spc.cgi?u=http://real_url
#        * or include this line at the end of your local file (before </body>),
#           replacing the indicator with the name of the file:
#           <img src="/~ctibirna/cgi-bin/spc.cgi?t=dot&u=indicator" border="0"> 
#
#
# That's all
# This code is free for you to use, modify and distribute.
# This code is provided AS IS, and with NO WARRANTY. The author
#   shall not be kept responsible for any consequences from the use,
#   distribution and modifications of this code. No responsability
#   is accepted for the results generated with this script or for
#   their interpretation
#
# Version 0.1 - 11Dec1998
#
# Version 0.3 - better DNS check, nslookup error trapping 
#
# Version 1.2 - 15Mar2002
#               better DNS check (use socket module),
#               functionalize,
#               support for hidden watermarks 
#			(one-pixel image in any local document)
#
# Version 1.3 - 19Mar2002
#               don't open the repository file if not necessary

##### Change this at your needs
saver       = '/users/ctibirna/public_html/cgi-bin/data/'
my_host     = '132.203.7.101'
#####

import os
import string
import cgi


def resolve_IP(requesterIP):
    import socket
    
    if requesterIP <> '':
        try:
            realname = socket.gethostbyaddr(requesterIP)[0]
        except socket.error:
            realname = requesterIP + ' [erreur DNS]'
    else:
        realname = 'no IP [???]'
        
    return realname

# predefined:
# the data file

############# YOU DON'T NEED TO CHANGE THE REMAINING CODE
# get the requested file's name
fields = cgi.parse_qs(os.environ['QUERY_STRING'])

dot_image = 0
if fields.has_key('t') and fields['t'][0] == 'dot':
    dot_image = 1
    
url = ''
if fields.has_key('u'):
    url = fields['u'][0]

if (not dot_image) and (url == ''):
    print "Content-type: text/html"
    print 
    print "There is an error in the page you visited"
    import sys
    sys.exit()
    

# now store the info if it's not myself
requesterIP = os.environ['REMOTE_ADDR']
if requesterIP <> my_host:
    from time import asctime, localtime, time
    moment = asctime(localtime(time()))
    realname = resolve_IP(requesterIP)
    entry = url + ' : ' + realname + ' : ' + moment + '\n'
    f = open(saver + 'repository','a');
    f.write(entry)
    f.close()

if dot_image:
    print "Location: http://giref.ulaval.ca/~ctibirna/img/dot.png"
    print "Content-type: image/png"
    print

else:
    print "Location: " + url
    print "Content-type: text/html"
    print