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Showing posts from October, 2008

Some more fun with SSH port forwarding and socks proxy

Few days ago I made the following post:

Prologue: Our Institute has several nice Dual Core Machines deployed for the students. Unfortunately the machines are behind a NAT with no port forwarded for external SSH access. Student's hostel is a bit far off from the computational centre. As such if someone felt the need of accessing the machines during non-office hours, it was a wee bit difficult. The sysadmin would not have agreed to forward any ports. Something had to be done....

SSH has a very useful feature - Remote and Local Port Forwarding. We have an old rickety PIII running Ubuntu 8.04.1 in the Hostel, it is connected to the net and is accessible via SSH from the internet. Using a tiny little shell script running on one of the machines in the Institute, I managed to make the old PIII an intermediate gateway for gaining SSH access to the Institute's machines from anywhere in the internet. The script is of few lines, but nevertheless powerful enough to serve our purpose.

#!/bin/…

XHTML 1.0 Standards - who cares?

It has been quite a few days, since I started Blogging. On the source code of my blog, it was proudly proclaimed <!DOCTYPE html PUBLIC "-⁄⁄W3C⁄⁄DTD XHTML 1.0 Strict⁄⁄EN" "http:⁄⁄www.w3.org⁄TR⁄xhtml1⁄DTD⁄xhtml1-strict.dtd">
I rushed off to W3C Markup Validator . The fist run showed up 437 errors! Quite high a number it was. Most of them were petty errors like unencoded ampersands in URLs, improper comments and the like. It is true, the extremely demanding XHTML 1.0 Strict standards sometimes becomes too much for web designers, but no one forces a designer to declare <!DOCTYPE html PUBLIC "-⁄⁄W3C⁄⁄DTD XHTML 1.0 Strict⁄⁄EN" "http:⁄⁄www.w3.org⁄TR⁄xhtml1⁄DTD⁄xhtml1-strict.dtd"> either. If Google Blogger is so keen to show off its "XHTML 1.0 Strict" compliance, then it should take up the responsibility that it remains true to its words. Simply asserting some compliance and then relying on the browser to do the rest of the hard wo…

Snapshots of my room in IISERK Hostel

... Neat and tidy .. isn't it ?
At the bottom of the rack (in the first pic) you can see Oak - our unofficial webserver, fileserver and network router for the hostel. On the table lies Mars - my Torrent Downloader and Music Player. It doubles up as a local mirror for some websites of our Institute's LAN. On the table also lies Pluto my almost always-on Compaq Presario V3018TU. All of them runs some flavor or the other of Ubuntu GNU/Linux. Oak and Mars runs Hardy Heron 8.04.1 LTS while Pluto runs Intrepid Ibex 8.10.

Fun with SSH Remote Port Forwarding

Prologue: Our Institute has several nice Dual Core Machines deployed for the students. Unfortunately the machines are behind a NAT with no port forwarded for external SSH access. Student's hostel is a bit far off from the computational centre. As such if someone felt the need of accessing the machines during non-office hours, it was a wee bit difficult. The sysadmin would not have agreed to forward any ports. Something had to be done....

SSH has a very useful feature - Remote and Local Port Forwarding. We have an old rickety PIII running Ubuntu 8.04.1 in the Hostel, it is connected to the net and is accessible via SSH from the internet. Using a tiny little shell script running on one of the machines in the Institute, I managed to make the old PIII an intermediate gateway for gaining SSH access to the Institute's machines from anywhere in the internet. The script is of few lines, but nevertheless powerful enough to serve our purpose.

#!/bin/bash
while [ 1 ]; do
ssh -C -o ServerAliv…

Changing the favicon for your blog

People who are not happy with the Orange and White Blogger favicon, can use their own instead. First create a 48 X 48 px image using Gimp or whatever software you prefer. Save the image as a .ico file, say myicon.ico. Upload the image to some webhost like Google Pages or Geocities (Picasa WebAlbum doesn't accept .ico files).
Next go to your Blogger DashBoard --> Layout --> Edit HTML.
Locate the line <head>
After the line insert the code-
<link href="http://imagelocation/myicon.ico" rel="icon">.
Replace http://imagelocation with your webhost's address. Save the template. The job is done. Refresh your Blog page, your own icon will appear instead of Blogger's.

Adding Social Bookmarking links like Digg, Delicious etc. in Blogger

With a little tinkering of the HTML code of the Blogger template, it is very easy to insert social bookmarking links like Digg, Delicious, Technorati etc. so that readers can directly bookmark the Blog post.
To add these links:
Go to your Blogger Dashboard, Click Layout --> Edit HTML. Then check - Expand Widget Templates
Search for the line: post-footer-line
Just after the line, add the following code:
<p/>Add to: <a expr:href='"http://digg.com/submit?phase=2&url=" + data:post.url + "&title=" + data:post.title' target='_blank'><img HEIGHT='20' WIDTH='50' src='http://lh4.ggpht.com/sambitbikaspal/SPAyI0pMJYI/AAAAAAAAAm0/THLvsaJKvJo/s144/digg-logo.gif'/></a> <a expr:href='"http://del.icio.us/post?url=" + data:post.url + "&title=" + data:post.title' target='_blank'><img HEIGHT='20' WIDTH='75' src='http://lh6.ggpht.com/sambitbikaspal…

Rendering LaTeX in Blogger.

Rendering LaTeX in Blogger is pretty easy thanks to the JavaScript LaTeX equation render engine from http://www.yourequations.com.
To enable LaTeX rendering go to the Blogger Dashboard --> Layout --> Edit HTML . Then add the line
<script> type="text/javascript" src="http://tex.yourequations.com/"></script>
<script type="text/javascript" src="http://tex.yourequations.com/"></script>
just before <body/>. Half the job is now done.
Then, for example to render:
\int_{0}^{\pi}\frac{x^{4}\left(1-x\right)^{4}}{1+x^{2}}dx =\frac{22}{7}-\pi
Use the code:
<pre lang="eq.latex">
\int_{0}^{1}\frac{x^{4}\left(1-x\right)^{4}}{1+x^{2}}dx
=\frac{22}{7}-\pi
</pre>
The LaTeX code will now be displayed as:
\int_{0}^{1}\frac{x^{4}\left(1-x\right)^{4}}{1+x^{2}}dx=\frac{22}{7}-\pi
Ofcourse Javascript needs to be enabled in the Browser for the renderer to work.

Durga Puja 2008

Photographs taken with Sony DSC W130 DigiCam, during the Durga Puja 2008 at Kharagpur.
Durga Puja is an autumn festival celebrated widely, mainly in the states of WestBengal and Tripura in India in honour of the Hindu Goddess Maa Durga.


Some snippets about Verisign's Personal Identity Portal

Recently I stumbled upon Verisign's Personal Identity Portal - pip.verisignlabs.com. Though still in Beta, I found it immensely impressive as an all-in-one Personal Identity Management Service.
It has a cool feature named One-Click Sign In, which allows signing in to a host of websites including Google, Yahoo, Flickr, Youtube among many others. The login credentials for the respective sites are required to be submitted. These will be encrypted using the users passkey. The only caveat for this excellent service is that one has to take Verisign's word for it, when it comes to security and privacy of the login credentials. Having trusted Verisign fully with one's secrets, all that is required is Bookmarking the One-Click sign-in link provided after submission of the credentials. Clicking on the bookmark leads to a list of the added sites, clicking on any of the sites directly signs the user in, ofcourse one has to be signed in to pip.verisignlabs.com prior to that.
Another feat…

Why the name - Bot Cyborg ?

The name of the blog followed the name of the domain I had registered. I was interested in the domain hack - cyb.org . Unfortunately it was already registered by someone. Looking for an alternative I registered botcyb.org . As one of my friends has correctly said, the domain name sounds as if it belongs to some spam bot :D . The blog was named just after the domain name.

Why blog?

A few days ago I was caught up in a discussion on this topic with one of my friends. Personally I was ( and still am ) somewhat against the idea of writing blogs. Naturally when I have set out writing my first blog, I've got to justify atleast myself why I am doing so.
Prologue:
I had been maintaining a tiny personal website on Googlepages. Coming to know about Google's decision to phase out their Googlepages service and replacing it with Google Sites, I started looking out for some other reliable but free host. I didn't find Google Sites very appealing. It doesn't allow hosting of custom HTML pages. Being a student shelling out bucks for paid hosting would have hurt my pocket a lot. Unfortunately most free webhosts will litter the page with crappy and tasteless ads. Yahoo! Geocities' free hosting was a good compromise.
Temporarily I moved my site to http://www.geocities.com/sammy_pal123 but was not very happy (somewhat happy to speak the truth) with it either as it d…