#!/bin/bash
##########################################################################
#Matthew Russell 14 Feb 05
#IPRefreshDaemon.scr
#Usage to launch as background process: [prompt]$./IPRefreshDaemon.scr &
##########################################################################
#
#Important: The commands you use in this script have to be consistent
#with your particular install of Linux. I've tested them to work on 
#Mac OS X Panther and on Mandrake Linux 9.1. They should work on any
#recent Linux distro, but make sure if you're in doubt
#
#Some explanation based on MY home network. YOUR home network will
#probably be different, but this recipe should require very little change:
#
#For my wireless router, I can type http://gateway.2wire.net
#into my browser and pull up a control center. Given this is the case,
#I can open up http://gateway.2wire.net/broadband/index.html to get a page
#that contains my external IP address that is assigned to my wireless
#router, which also happens to be my default gateway.
#This IP Address is the one that separates me from the WWW and can use
#when redirecting users to my private server. I use this method to obtain
#my IP address because it's simple and because my DSL provider uses DHCP,
#which means that my external IP address can periodically change. If I 
#don't periodically rewrite the page that redirects, users will get
#transferred to a bogus site or no site at all.
#
#As root in linux or on your Mac, you can type "ifconfig" at a prompt,
#but if you're running a home network, you'll see your internal IP
#address. Again, you want your EXTERNAL IP address
#
#Some helpful notes for you:
#
#If you have a static IP address, you won't need to do this and can just
#hardcode your redirect page. If you're unsure as to whether or not
#you have a static IP address, you probably don't. Unless you have
#a 2Wire Home Portal, this exact script won't work for you, but your 
#wireless router or internet provider *should* be able to tell you how
#to get this info, and this script should require very minimal changes.
#
#Check and double check paths and permissions:
#	Make sure cadaver is in the path if you use it. Type "which cadaver"
#		to make sure it's in there
#	Make sure permissions are set for any script (including this on you try
#		to run. Type "ls -al filename" to check permissions and use
#		"chmod u+x filename" to add executable permissions.
#
#Use the man pages to get help on commands. Type "man commandname" at any prompt
###########################################################################

#loop forever and update the IP address every 5 minutes. This means if you 
#want to kill this process you have to do it manually.
#Use the killRefreshDaemon.scr script to do that.

######### USER PREFS ############
REDIRECT_PAGE="frames.html"
REFRESH_INTERVAL="1m" #anywhere up to ~5m is reasonable
#################################

#must have spaces inside brackets!
#no indent
while [ 1 ]; do

#get the page that contains my IP Address and suppress any output from wget
#this is probably different for you
wget -q "http://gateway.2wire.net/broadband/index.html"

#Use a regex to pull out the IP Address with the help of our friend Perl
#From looking at the HTML source to the page for MY network that contains
#this info, I know it's in a line like this:
#<td valign="bottom" class="monospace" nowrap="nowrap">123.456.789.012</td>

#Save only the IP address to a file as text
perl -n -e 'if (m#([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+)#) {print "$1\n";}' \
	index.html > /tmp/ipAddress

#clean up the file, or else subsequent wget calls save them like
#index.html.1, index.html.2, etc.
rm -f "index.html"

#For component testing, uncomment the following "cat", and run the 
#script. You should see only your IP address of the form 
#WWW.XXX.YYY.ZZZ as output if things are working correctly up to here

#cat ipAddress

#freshen the IP address
perl -i -p -e "s#[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+#`cat ipAddress`#" $REDIRECT_PAGE

#just in case you want to do it in sed and learn some new tricks.
#sed -e "s#[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*\.[0-9][0-9]*#`cat ipAddress`#" $REDIRECT_PAGE > frames.html

#copy the freshened $REDIRECT_PAGE to the correct directory of your iDisk:

#If you mounted your iDisk with Finder and are using your Mac, this is as easy as:
#cp -f $REDIRECT_PAGE "/Volumes/.Mac Username/Sites/Correct Subdirectory"

#if using the patched version of cadaver, use something along these lines
#once you've compiled it and added it to your PATH. The final "> /dev/null" redirects
#any output from cadaver to the bit bucket
cadaver http://idisk.mac.com/Username/Sites/ -U Username -P password -S $REDIRECT_PAGE > /dev/null

#copying an existing file with cadaver should automatically rewrite over the old
#Again, see the README file that came with cadaver for more complete info.

#At this point, just wait a while and repeat the process
sleep $REFRESH_INTERVAL
done #with the while loop