Sai Charan

Anyconnect VPN on Ubuntu x64

2012-02-04T12:16:28-08:00

Connecting to the VPN website to launch Anyconnect installer was not helping -- either with Firefox, nor with Chrome. The Applet kept loading to eternity with no installation. Chanced upon http://blog.mattwoodward.com/installing-cisco-anyconnect-on-64-bit-ubuntu, which suggested that on Firefox, I disable the IcedTea-Web plugin for Java Applets -- and it worked. After the disable, I was given a link to download the installer for 'Linux _x86_64' platforms, which when run installed the VPN without any further hassle.

Quest for a good Antivirus

2012-01-26T11:55:41-08:00

I have long been a loyal customer of Norton Internet Security product -- and I can vouch for its comprehensive, effective protection. However, when my most recent subscription expired, due to my Grad-student budget I decided to try other alternatives that I had access to via other subscriptions, or free software.

My ISP, Charter Inc. provides its users a security solution titled 'Charter Security Suite' which in turn is an offering from F-Secure. While I have been skeptic of anything other than Symantec/Mc Afee/Zone Alarm, I decided to give it a try. After all, F-Secure is a for-profit organization and I must be paying for it indirectly (by paying my ISP).

It turns out to be quite noisy. I have grown used to Norton silently making decisions for me based on its Symantec WINE. But being an early adopter, I occasionally did manually choose my trust levels with Norton. The Charter Security Suite on the other hand, asked me if I trusted Google Talk, Yahoo Messenger and nearly every other prevalent software out there.

And, curiously, this antivirus was not the first program to startup. It usually started after quite a few software that connect to the Internet were up and running -- bad, right?

And then there was that fiasco with one software update -- Charter's suite asked me if I trusted the exact same binary about 30 times! That was the limit.

I had the free Microsoft Security Essentials running on my parent's PCs and they never mentioned it nor was there any incident of virus on their systems - a good thing. So I decided to try it. Install was a breeze and the quick scan completed in under 15 minutes without affecting my system performance. Nice!

But I was not comfortable with no firewall on my Windows PC -- enter Zone Alarm. I had used it a master's student and remember being very satisfied with it. The download size (~150MB) was a bit of a brow-riser, but the install and setup was fantastic. Funnily, I kept waiting for ZoneAlarm to pop-up and ask me to set up something -- but good thing I was disappointed there. I then dug into the settings to find all in good shape -- software that I trusted was already trusted; no pesky pop-ups.

So that is my current setup - Microsoft Security Essentials and ZoneAlarm Firewall - both free & so far so good.

Reading on the Internet

2011-11-01T14:52:19-07:00

I tend to have this belief that one spends a fair amount of your time reading on the internet. If that is true now or in foreseeable future, you may want to read on.

There has been a fair amount of work on making the world a more readable place. Of these, three tools are on my radar: http://readability.com, http://instapaper.com and Safari's Reader mode.

Readability.com specializes in making your reading experience a good one: it removes clutter, ads and all that and shows you just text. And renders it beautifully at that. They have a paid app and also a free bookmarklet that lets you do this.

http://Instapaper.com is basically a reading list (read later option) that you can access from any browser with a native iPad/iPhone/iPod paid app. However, my interest in this is mostly the bookmarlket that cleans up the text.

On the heels of Instapaper and Readability, Apple released a browser in-built 'Reader' mode. Simply click on the reader button in the far end of the address bar for web-pages that are 'readable' and you are presented with a fantastic clean view of the content. So far, my favorite has been readability.com's bookmarklet, but now I find myself doing all my reading in Safari browser (available even for PC). See this for what I mean: http://www.apple.com/safari/whats-new.html#gallery-read-reader

Very easy on the eyes and zero distraction. Highly Recommended.

Default runlevel on CentOS

2011-10-26T08:20:18-07:00

A reminder to self (this should work for all BSD-like systems, including Fedora & RHEL) —

Edit /etc/inittab as root. The number after the first colon after id is the default runlevel.

id:3:initdefault:

BTW, I prefer runlevel 3 (no GUI).

Reference: http://www.centos.org/docs/5/html/Installation_Guide-en-US/s1-boot-init-shutdown-sysv.html

Ubuntu 11.10, PuTTy, tmux & UTF-8

2011-10-17T01:46:22-07:00

After the upgrade today, firing up a tmux session via PuTTy with my usual "Session Settings > Translation > Remote Character Set" pointing to "ISO-8859-6:1999 (Latin/Arabic)", I found that line drawings were all messed up: the lines were drawn with the 'a' like characters, instead of lines. It occured to me that the newly updated Ubuntu ncursesw libraries and/or tmux may have fixed something. Promptly switching to 'UTF-8' as the remote character set brought back the good looking line-drawings.

Gitweb with 'side-by-side' diff

2011-10-09T23:20:40-07:00

Bonus: Simultaneously scroll left and right files with overflow.

Dependencies: jQuery

Usage: Simply include jQuery in gitweb/gitweb.cgi (within the head tag).

Future work: Going by this thread on kerneltrap.org, 'side-by-side' diff appears to have been on the team's TODO list and never gotton around to being implemented. So, except for the simultaneous scrolling, I intend to port this to Perl and hope to get it integrated into Gitweb core. Simultaneous scrolling needs to be done in Javascript and the fact that external dependencies are frowned upon,

Note that we frown upon introducing extra dependencies for gitweb, unless they are optional, and best detected automatically.

scrolling needs to be handled separately in gitweb.js (the currently implementation depends on jQuery).

Screenshot:

Gist: https://gist.github.com/1274726

Richard Stallman & Steve Jobs

2011-10-08T12:24:16-07:00

Richard Stallman wrote:

Steve Jobs, the pioneer of the computer as a jail made cool, designed to sever fools from their freedom, has died.

As Chicago Mayor Harold Washington said of the corrupt former Mayor Daley, "I'm not glad he's dead, but I'm glad he's gone." Nobody deserves to have to die - not Jobs, not Mr. Bill, not even people guilty of bigger evils than theirs. But we all deserve the end of Jobs' malign influence on people's computing.

Unfortunately, that influence continues despite his absence. We can only hope his successors, as they attempt to carry on his legacy, will be less effective.

When I first read it, I was shocked. Somehow, my respect and admiration for Steve, and the news of his demise seemed to confuse the whole thing. Perhaps, I thought, Stallman did not wait 'the appropriate amount of time' after Jobs' passing - but hey, what is the appropriate amount of time? As Gruber put it, '...life goes on.'

I could sense a fringe thought that I seemed to be actively fending away: that there was some truth in Stallman's words; and that he was being very respectful in what he said. But then, I could not place my thoughts - like I mentioned earlier, I seemed to be in a limbo of sorts.

And then there was light! Dave Winer, the guy credited with inventing RSS, first tweeted this

Stallman's epitaph for Jobs is appropriate and respectful. http://r2.ly/7f3u

and followed up with this. And I seem to agree - Stallman was right; and appropriately respectful too. Brilliant, well thought out & effectively communicating piece of writing from Dave.

To relate with the concluding paragraph from Stallman, it helps to be familiar with Apple's 'Think Different' ad campaign. A transcript of it is here: http://saicharan.in/blog/2011/10/06/heres-to-the-crazy-ones/

Here's to the Crazy Ones

2011-10-06T18:56:06-07:00

The Loop linked to a video on Youtube and titled it 'Steve Jobs narrates The Crazy Ones'. Here is a transcription (puctuation & emphasis is as I inferred, listening):

Here is to the crazy ones. The misfits. The rebels. The trouble makers. The round pegs in the square holes; the ones who see things differently. They're not fond of rules and they have no respect for the status quo. You can quote them, disagree with them; glorify or vilify them. About the only thing you can't do is ignore them - because they change things. They push the human race forward. While some may see them as the crazy ones, we, see genius. Because people who are crazy enough to think they can change the world, are the ones who do.

And the video:

Steve on Courage, Heart and Intuition

2011-10-06T01:50:10-07:00

...have the courage to follow your heart and intuition. They somehow already know what you truly want to become. Everything else is secondary.

Remembering Steve Jobs

2011-10-06T00:38:16-07:00

In his commencement address at Stanford, Steve Jobs said (Stanford News)-

Remembering that I'll be dead soon is the most important tool I've ever encountered to help me make the big choices in life. Because almost everything — all external expectations, all pride, all fear of embarrassment or failure - these things just fall away in the face of death, leaving only what is truly important. Remembering that you are going to die is the best way I know to avoid the trap of thinking you have something to lose. You are already naked. There is no reason not to follow your heart.

In the light of this, as @roshnimo notes, it feels a tad foolish to mourn. 

Texnic Center error 'pdflatex.exe: Could not Initialize GUI'

2011-09-04T17:02:07-07:00

Another note to self —
This error only means that MikTeX was unable to find and/or install some missing packages. To fix this (on Windows), run 'mo.exe' from the command prompt and choose 'Yes' for 'Install missing pacakges on-the-fly'. ('Ask me first' did not work for me).

quote: You want to know how to do it

2011-09-03T10:01:34-07:00

You wanna know how you do it?

Here's how, they pull a knife, you pull a gun. He sends one of yours to the hospital, you send one of his to the morgue. That's the Chicago way.

Jekyll feature: Retain Modified Time Stamp

2011-09-02T12:54:03-07:00

To ease publishing via Jekyll, I needed to push via FTP to my hosting provider. I decided to the perl utility from sourceforge: ftpsync. However, running it made me notice that Jekyll always regenerated all files and obviously, they had a 'now' timestamp. This was basically throwing off the FTPSync utility which ended up pushing the entire site, defeating the very purpose of the utility.

So, I made a two line fix that handles static pages and _posts/ as follows: The time stamp of the markdown/static page is copied to the published post page. So, even though Jekyll regenerates the entire site, the timestamps are adjusted to prevent unnecessary push via tools like FTPSync. Note that other pages will still have the 'now' timestamp.

The diff can be viewed here. Feedback/suggestions welcome in comments.

URL Selection in Putty

2011-09-01T15:26:22-07:00

Finally! Used this article to fix the partial URL selection problem with PuTTy. In addition to ':', I also 'set to class 2' the characters: '?' & '#'.

Tributes to Steve Jobs

2011-08-25T11:15:00-07:00

Here are a few more reflections from people I read:

Steve, if for some crazy reason you're reading this:

You've defined a generation and changed the world.

Thank you.

We wish you the best.

May be I'll add a few more as they pop up.

When GOD called Vic Gundotra

2011-08-25T10:10:00-07:00

Being an Apple fanboy, I enjoyed this piece. It is interesting that after Steve Jobs resigned, many such stories have surfaced.

Vic Gundotra recalls:

Steve laughed. He said, "Vic, unless the Caller ID said 'GOD', you should never pick up during services". [...]

and concludes -

But in the end, when I think about leadership, passion and attention to detail, I think back to the call I received from Steve Jobs on a Sunday morning in January. It was a lesson I'll never forget. CEOs should care about details. Even shades of yellow. On a Sunday.

To one of the greatest leaders I've ever met, my prayers and hopes are with you Steve.

Nice!

When Steve Held Open the Door

2011-08-25T09:40:00-07:00

David Cairns writes:

Anyway, I knew the distance pretty well, so when I sensed that I was reaching the other side of the quad, I opened my eyes and looked down and Steve was holding the door for me, grinning to himself. I have no idea how long he had been holding it, though it was probably only a couple seconds, long enough to cause him to smile at my basking in the open air.

Those couple seconds probably cost Apple $1.4bn.

Must have quite an experience!

Static Blog Using Jekyll

2011-08-24T00:00:00-07:00

This is what it took me to migrate from WordPress to Jekyll:

Import blog using the wordpressdotcom importer.
Use Disqus WP plugin to export comments into Disqus.
Generate static pages (include Disqus code in Jekyll template).
Add search functionality.
Add personal pages (about/search/rss).

Done! (A preview is available here.)

Update:

Adding tags was a lot more effort. A little help from this gist saved the day.
Adding pages for year, month and day was a ton more effort. I modified archive.rb from josegonzalez and also customized his _layout/archive_*.html
Added an error handler with some JS to show my own custom error page.

You can find the sources here: https://github.com/scharan/scharan.github.com.

Update:

I also modified metajack's jekyll.el to add a date: header (with date & time) on publish: https://gist.github.com/1171592. The gist:

Migrating to Jekyll

2011-08-22T00:00:00-07:00

Ah! The joy of markdown! I preferred to write text, not markup. As @gruber states at the opening, markdown allows me write simply. However, it was painful to blog with this workflow:

write in markdown
convert to HTML
copy paste the HTML to blog editor
publish

It was just too painful. Enter Jekyll. I first came across Jekyll here on allthingsdistributed.com. Tom Preston-Werner (Jekyll's author) notes here, he needed something simpler - so he wrote Jekyll. I liked my new munich theme, and so wrote my own index.html, default.html, post.html and css. You can see the work in progress here: aws.saicharan.in.

SaveURI has a new home!

2011-08-18T00:00:00-07:00

On Github: https://github.com/scharan/saveuri

Persisting/restoring ssh-agent across screen/tmux sessions

2011-08-15T00:00:00-07:00

As a heavy user of screen and now of tmux, I find it annoying that each time I disconnect the terminal and reconnect and then reattach to screen/tmux, I find that inside the screen/tmux sessions, SSH_AUTH_SOCK variable is stale: it does not point anymore to the 'current' agent.pid file. So, here is a script to fix that: https://github.com/scharan/Goodies/blob/master/ssh-agent-restore

'gitweb' setup without root access

2011-08-14T00:00:00-07:00

Setting up gitweb on a machine with no root access:

First, set up lighttpd:

Download from http://www.lighttpd.net/download

  $ mkdir -p ~/usr
  $ tar -xvf lighttpd-*; cd !$;
  $ ./configure --prefix /home/<you>/usr
  $ make
  $ make install ## lighttpd is now at ~/usr/sbin/

- Now, if all is well, you should be able to run git instaweb in your local git repository.

- If you see a message like base-docroot not found at /PATH/TO/SOME/WHERE, then it probably did not find that directory.

To resolve this, you can do one of two things:

1. Find the directory named gitweb/ that contains index.cgi, gitweb.cgi and static/ and run

  $ git config --get instaweb.gitwebdir "/PATH/TO/gitweb/" (I figured this from /usr/bin/git-instaweb)

2. Emulate a local install

  $ mkdir -p ~/www/static
  $ git config --get instaweb.gitwebdir "/home//www"
  $ scp ssh://my-ubuntu-machine-with-sudo-access:/usr/share/gitweb/* ~/www/
  $ scp ssh://my-ubuntu-machine-with-sudo-access:/usr/share/gitweb/static/* ~/www/static
  $ cd git-repo; git instaweb;

- If it instead start and you then see an error like: 404 Not found, the folder exists but

- the index.cgi file is not found, simply do step 2 above.

Setting up highlight (on a machine with no root access):

- Download hightlight from here: http://www.andre-simon.de/zip/download.html

$ tar -xvf hightlight*; cd !$;

$ make

$ edit 'makefile'

       # Destination directory for installation (intended for packagers)
       DESTDIR =
       # Root directory for final installation
       PREFIX = /home/csgrads/scharan/usr # or something appropriate.
       $ make install
       $ PATH=$PATH:~/usr/bin/:

- Download lua from here: http://www.lua.org/ftp/lua-5.1.4.tar.gz

     $ make linux
     $ Edit makefile to point INSTALL_TOP to ~/usr/local

- Edit ~/www/gitweb.cgi: enable highlight feature (you gotta grep for it).

Vonage Usage: Python Script

2011-08-09T00:00:00-07:00

This eases checking international minutes used with a Vonage World plan http://saicharan.in/work/vonage.py. Just put in your vonage username/password in the script. You would also want to

$ sudo pip install libxml2dom

Further, to avoid manual check, here is a crontab entry to automatically check usage at 6 AM everyday. It then emails you if you have overshot the usage (defaults to 3000 mins/month). My mail.sh is available on: Github.

0 6 * * * vonage.py 1>/tmp/vonage-mail; ret=$?; if [ $ret -ne 0 ]; then mail.sh "Vonage Usage: $ret" /tmp/vonage-mail; fi

The script:

Readability for Chrome: Save to Instapaper

2011-08-08T00:00:00-07:00

I love readability (readability.com) for the clutter free reading experience. As a student, I prefer freebies. Instapaper does a great job of reading lists - and its free too. I wanted to combine the Readability's 'Read Later' shortcut (shift + `) to save to Instapaper. Turns out, its easy:

On Windows, goto: %USERPROFILE%\AppData\Local\Google\Chrome\User Data\Default\Extensions\oadggleneidfmbhhedlildjnpgcggmch\1.6_0\js

On Ubuntu Linux, goto: ~/.config/chromium/Default/Extensions/oadggleneidfmbhhedlildjnpgcggmch/1.6_0/js/

Replace the contents of 'save.js' with the script below. ~~You will have to replace with the string that follows instapaper.com/j/ in your personal bookmarklet - sorry, its a wee little bit more effort.~~ Found a way to avoid user specific token. This works out of the box.

That piece of code is and adaptation from Instapaper's 'Read Later' bookmarklet: http://www.instapaper.com/extras

Now simply disable/re-enable the Readability plugin, open (or reload if already open) the page you wish to 'read later' and hit (shift + `) keys. If you are logged in with Instapaper, you should see the Saved! popup on the top left. Else, you will be prompted to login and then Instapaper saves your bookmark, returning you to the page you were on.

Neat!

Indian Almanac Bookmarklet

2011-08-08T00:00:00-07:00

Traditional events require fairly strict observances throughout the year. For this, I tend to rely on the online service: http://mypanchang.com. Though I bookmarked the page, it is error prone in that you will be always be shown the date that you bookmarked. Instead, it would be of immense help to view today's almanac. So, here is my bookmarklet for showing today's almanac for Los Angeles. You can edit it to show your city's almanac by looking at the URL for your city from here: http://www.mypanchang.com/selectyourcity2011.html

Bookmarklet: LA South Indian Almanac

Texnic Center and Adobe Reader X

2011-05-04T00:00:00-07:00

After I upgraded to Adobe Reader X, Texnic center started throwing up an error:"[DocOpen("%bm.pdf")][FileOpen("%bm.pdf")] Cannot execute the command."

Digging up a little on Adobe DDE, I found a solution here: http://forums.adobe.com/message/3301219#3301219

Here is the fix: Build > Define Output Profiles > Choose 'LaTeX => PDF' > Viewer tab. In three locations where 'acroview' is the value, change it to 'acroviewR10' and you are good to go!

gContactSync bug

2011-04-12T00:00:00-07:00

Found a weird behavior with gContactSync 0.3.2 Thunderbird plugin- on both Windows and Linux (Fedora 14), the sync stops after 111 contacts. Poked around the internet and found that there were no documented bugs on this.

Decided to fix it for myself cos I found that it really syncs all the contact information to Thunderbird, including the photo.

gContactSync has a nice 'verbose log' feature for debugging information - but was not of much help since the log stopped after 111 contacts.

Next tool for me was the 'Error Console' in Thunderbird. Not surprisingly, I found an error on line 181 in content/GContact.js, that read " 'type' not defined" :

181 type = type.substring(type.indexOf("#") + 1); 
182 return new com.gContactSync.Property(arr[i].childNodes[0].nodeValue, 
183                                                                        type);

Darn! Just as a test, I simply pre-pended 'if(type)' to line 181, resulting in:

181 if(type) type = type.substring(type.indexOf("#") + 1); 
182 return new com.gContactSync.Property(arr[i].childNodes[0].nodeValue, 
183                                                                        type);

It worked! Not really got a chance to investigate what happens/does not happen when 'type' is NOT defined, but things seem to work for now. I also submitted this here: http://www.pirules.org/extensions/submit_error.php

Mapping Win key in Fedora (14)

2011-04-08T00:00:00-07:00

Learnt/inferred a few things here [correct me via comments if I am wrong conceptually; note that these have worked for me] -

Win key is called/referred to as the 'super key'
You may have to get xmodmap to explicitly recognize the key.
You can get the keycode for any key using 'xev' command, as discussed here: http://forums.fedoraforum.org/showpost.php?s=9af5fdea1041e19ff96815fb3470f904&p=913923&postcount=9
Once you find out the keycode for you Win key, you can get xmodmap to 'recognize' it as noted in http://forums.fedoraforum.org/showpost.php?s=9af5fdea1041e19ff96815fb3470f904&p=913308&postcount=3
Then, configure Win+key combinations via System > Preferences > Keyboard Shortcuts.

SaveURI Updated for Firefox 4

2011-03-31T00:00:00-07:00

Made some time to update the firefox extension at https://addons.mozilla.org/en-US/firefox/addon/saveuri/

It was a more than a minor compatibility break. I have submitted the new version for review. But for those of you wish to test it for me, here is a link: http://saicharan.in/beta/saveuri/saveuri-0.3.3-fx.xpi

Warning: This has not yet been approved by a Mozilla reviewer - for testing only!

Instructions: If your Firefox browser saves the file rather than install it, simply drag and drop the file to the browser window and restart your browser!

Update: The extension has been approved and is now available at https://addons.mozilla.org/en-US/firefox/addon/saveuri/ Thanks everyone for the geek-joy!

while(a++ == b++)

2010-05-11T00:00:00-07:00

Among the most elegant implementations is the string copy function (assuming you have allocated enough memory in the dest buffer):

//Assuming for elegance you don't have to return the number of bytes copied.
void strcpy(char* src, char* dest){
while(*dest++ = *src++);
}

But I have often wondered what happens at the assembler such *s gets you only a single byte/character. So here is a simple program that explores this - but in string compare:

int main(){
    char *a="String One", *b="String Two";
    while(*a++==*b++);
return 0;
}

I compiled this with 'gcc -S' option and got the following assembly code:

        .file	"testpointer.c"
	.def	___main;	.scl	2;	.type	32;	.endef
	.section .rdata,"dr"
LC0:
	.ascii "a\0"
LC1:
	.ascii "b\0"
	.text
.globl _main
	.def	_main;	.scl	2;	.type	32;	.endef
_main:
	pushl	%ebp
	movl	%esp, %ebp
	andl	$-16, %esp
	subl	$16, %esp
	call	___main
	movl	$LC0, 8(%esp)
	movl	$LC1, 12(%esp)
L2:
	movl	8(%esp), %eax
	movb	(%eax), %dl
	movl	12(%esp), %eax
	movb	(%eax), %al
	cmpb	%al, %dl
	sete	%al
	incl	8(%esp)
	incl	12(%esp)
	testb	%al, %al
	jne	L2
	movl	$0, %eax
	leave
	ret

Line 24: "cmpb %al, %dl" says it all. compare Lower Byte of register 'a' and register 'd'. Now I can be in peace ;) References: http://www.codeguru.com/cpp/cpp/cpp_mfc/tutorials/article.php/c9415 http://www3.itu.edu.tr/~kesgin/mul06/intel/instr/sete_setz.html http://homepage.mac.com/randyhyde/webster.cs.ucr.edu/www.artofasm.com/DOS/ch09/CH09-6.html#HEADING6-83

Efficient Substr implementation

2010-05-10T00:00:00-07:00

I came up with this implementation of substring method. Anyone got ideas to make it more terse and more efficient?

bool substring(const char* str, const char* substr){
	const char *currentString = str, *backTrackString = str, *currSubstr = substr;
	while( strlen(backTrackString) >= strlen(substr) ){
		while( *currSubstr && *currentString++ == *currSubstr++);
		if( !*currSubstr ) return true;
		currentString = backTrackString++;
		currSubstr = substr;
	}
	return false;
}

In particular, can we do without atleast one of the local variables - while still being as efficient or better? A more basic question - so you think this is efficient?

Binary Search Tree

2010-05-10T00:00:00-07:00

The following code tests if the input binary tree is, in fact, a Binary Search Tree. This was as terse as I could get it. Any got more terse code? Suggestions/comments welcome.

bool IsBST(TreeNode* node){
	if( !node ) return true;// trivially true.
	if( node->left )
		if( node->left->val > node->val ) return false; //fail early
	if( node->right )
		if( node->right->val < node->val ) return false; //fail early

	return ( IsBST(node->left) && IsBST(node->right) ); //recursively test subtrees
}

Update: Notice the tail recursion? Its super-efficient! Update-update: Thanks to Kartik (see comments below) for pointing out that the last line is NOT tail-recursive. Yet another update: The algorithm is does NOT check for IsBST(). The criterion of root being greater than all right children and smaller than left children is not always checked. See http://en.wikipedia.org/wiki/Binary_search_tree for more details.

With Great Power Comes Great Responsibility

2010-05-07T00:00:00-07:00

I was working on a remote FreeBSD system and issued a sudo command. I really liked what the 'preamble' to the password: prompt was -


We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:

#1) Respect the privacy of others.
#2) Think before you type.
#3) With great power comes great responsibility.

Password: With great power comes great responsibility - and my mind instantly went to this story: http://www.justpasha.org/folk/rm.html Hail Unix!

JS e-mail Validator

2009-11-19T00:00:00-08:00

NOTE: I have avoided character classes to aid understanding for newbies. Wizards, bear with the verbosity! Came up with this nice little email validator JS regexp. Someone got something shorter?

function validateEmail( email ){
var emailRe = new RegExp("^[a-zA-Z]+([a-zA-Z0-9_]*.[a-zA-Z0-9_]+)*@([a-zA-Z0-9_]+.[a-zA-Z0-9_]+)*$",'i');
return( emailRe.test( email ) );
}

Does this miss any cases? Try it out here: Update: This script allowed '*' in the email ID. The correct re would be:

var emailRe = new RegExp("^[a-zA-Z]+([a-zA-Z0-9_].[a-zA-Z0-9_]+)+@([a-zA-Z0-9_]+.[a-zA-Z0-9_]+)+$",'i');

Bug again! The '.' character outside the character class [] matches *ANY* single character. This, however, definitely works!

var emailRe = new RegExp("^[a-zA-Z]+([a-zA-Z0-9_.][a-zA-Z0-9_]+)+@([a-zA-Z0-9]+([.a-zA-Z0-9_])+)$".'i');

The test code now does not permit '*' in the email ID.

Interesting recursion problem

2009-11-12T00:00:00-08:00

Found this interesting recursion problem on StackOverflow. http://stackoverflow.com/questions/1705374/how-to-capture-a-string-into-variable-in-a-recursive-function

int resultSize( vector< vector<string> > vector ){
    int x=1;
    for( int i=0; i<vector.size(); i++ )
       x *= vector[i].size();
    return x;
}

vector<string> enumAll(const vector< vector > allVecs ){
    //__ASSERT( allVecs.size() > 0 );
    vector result;
    if( allVecs.size() == 1 ){
        for( int i=0 ; i< allVecs[0].size(); i++){
	    result.push_back( allVecs[0][i] );
        }
    return result;
    }
    const vector< vector<string> > tempVector(allVecs.begin()+1, allVecs.end() );
    vector tempResult = enumAll( tempVector );// recurse
    int size = resultSize( tempVector );
    for( int i=0; i<allVecs[0].size(); i++ ){
       for( int j=0; j<size; j++){
          //enumAll on each tempVector is called multiple times. Can be optimzed.
          result.push_back( allVecs[0][i] + tempResult[j] );
        }
    }
}

Also see the other solution by Young which solves this problem using tail-recursion. It is interesting problem in itself to transform a plain recursion into tail-recursion. The general method to do this is to eliminate the need for any processing post recursion. For this, one needs to pass all the data as parameters. This is pretty obvious when comparing the two solutions. Plain recursion takes only one parameter, while tail-recursion takes a lot more parameters. In my view, the advantage of plain recursion is pedagogy: it is very easy to follow the algorithm - the divide and conquer is so very obvious! With tail-recursion, we manually do a lot of book-keeping. This part is not so obvious in the present example. Plain recursion: http://stackoverflow.com/questions/1705374/how-to-capture-a-string-into-variable-in-a-recursive-function/1723192#1723192 Tail Recursion: http://stackoverflow.com/questions/1705374/how-to-capture-a-string-into-variable-in-a-recursive-function/1707808#1707808

Stackoverflow Teacher Badge

2009-11-11T00:00:00-08:00

Yay! Just got the stackoverflow teacher badge! Yay!

Metaprogramming is not magic

2009-11-03T00:00:00-08:00

I have always wondered why I like programming languages like Lisp etc. Sort of found an answer here: "Metaprogramming is not magic. It is simply another tool in the prepared programmer's toolbox. It's awfully nice when that tool is also part of the programming language we use. Otherwise, we are limited in what we can say conveniently in our programs by the somewhat arbitrary lines drawn between real and meta." Source: http://www.cs.uni.edu/~wallingf/blog/archives/monthly/2009-11.html#e2009-11-02T18_59_40.htm

What I read, am reading and want to read

2009-10-12T00:00:00-07:00

This is a list for my reference. It will be a "live" post and act as my SPOC for reading. In progress: - Beautiful Code - Code Complete 2 - The Pragmatic programmer - Structure and Interpretation of Computer programs Done: - The Lost Symbol - The mythical man-month - Joel on Software - More Joel on Software - make (O'Rielly) Wishlist: - Coders at work by Peter Siebel - The Innovator's Dilemma - Elements of Style - Godel, Escher & Bach - The story of Civilization by Will & Durant - Paradigms Of Artificial Intelligence Programming by Peter Norvig - The design of everyday things - Founders at work - The Brothers Karamazov

Why hitting 'reload' speeds up page rendering

2009-08-17T00:00:00-07:00

This is a response to David Pogues' tweet question: http://twitter.com/Pogue/status/3332520918 The 'rendering' or 'drawing-model' of a browser is based on HTML. Each visual in HTML element is defined by a HTML 'tag'. For browsers to display/render the page, they need some a certain amount of HTML tags to be available. So when you are faced with a blank page, it means that the browser is waiting for the HTML. Now, when you hit the reload button, remember that a part of the page has already been downloaded to the browser. Instead of discarding this info, the browser merely spits it out onto the window (thus displaying the page partially) and requests for the page once again. Now that a part of the page is already displayed (even if only partially), the user believes that the page has rendered rather quickly. If you hit the stop button, however, you will be stuck with a blank page. By hitting stop, you are telling the browser 'dont bother to try and render this page'. By hitting reload, you are still showing interest. Another way to observe progressive rendering is while the page is loading ( the browser shows a blank or a partially rendred page), go to File > Work Offline (in Firefox). You will see the page quickly render the partial page that was succuessfully downloaded. It is a sort of 'best-effort' service. Related concept: Progressive rendering. Jeff Atwood's take on the 'Lost Art of Progressive Rendering': http://www.codinghorror.com/blog/archives/000444.html This means that browsers don't need to really download the entire page before it can be displayed to the user. But, this depends on how the page has been desinged: http://www.vbulletin.org/forum/showthread.php?t=161099.

Deleting files

2009-08-06T00:00:00-07:00

In my quest for speeding up automated, no-questions asked deletion of the corrupt dev SDKs (which go upto 25 GB), I discovered this:


> rmdir /S /Q .

I even timed it this time: about an hour to delete a 25 GB SDK. And no questions asked. The above command does not write any output to the console! While this can be quite disconcerting initially, it does save a lot of computation time and resources ( I/O is the most expensive operation, remember? ). Earlier on, I used to use > del /s /f /q *. . But that used to delete only the files and not the directories. Deleting the directories manually was another pain. Also, this command had the habit of “informing the user” of what it is deleting – and would take about 3 to 4 hours! Do let me know if you find some faster way to delete the SDK!!

HN Submit button

2009-07-12T00:00:00-07:00

I have been attempting to add "share" functionality to my website. Initially, I used the Digg button (http://digg.com/tools/integrate) and Reddit button (http://www.reddit.com/button). Next I wanted to add Hacker News button. But there was none. But then again, there was this bookmarklet (http://ycombinator.com/bookmarklet.html). So I created the required HTML to get the required functionality, just using the bookmarklet:

<a href="javascript:window.location=%22http://news.ycombinator.com/submitlink?u=%22+encodeURIComponent(document.location)+%22&t=%22+encodeURIComponent(document.title)"> Submit </a>

Then I thought of making a Hacker News submit button, just like Reddit and Digg. So I decided to read the sources and build the HN button based on that. Man, Digg's JS was such mess (yes, it was the minified version, but still, far too many lines of code). Reddit's was a great deal simpler, easy-to-read and intuitive. Check them out: http://digg.com/tools/diggthis.js and http://www.reddit.com/button.js. So I modelled the HN button based on Reddits' Javascript. Here it is: http://saicharan.in/work/hn.js OR https://github.com/scharan/Goodies/blob/master/hn.js To use it, simply include the following line:

<script type="text/javascript" src="http://saicharan.in/work/hn.js"></script>

Here is the code: Update: This article briefly made it to the front page of HN! I saw it at #19!. Here are the comments from HN: http://news.ycombinator.com/item?id=700053

GMail: Automatic Message Translation

2009-07-12T00:00:00-07:00

This morning GMail surprised me yet again. Opening an email, I saw a new functional bar: Translate this message: From:<Language> To:<Language>. I tried out the machine translation from English to Hindi. It was amazing. Took under 2 second (yes, to send the request to the servers, do the translation and to render the translated text on the browser window). There was also that pretty helpful (right-)side bar: "Translate this conversation". Pretty neat translation. And very seamless user experience too! Man I am blown away.

Redirecting blogger traffic

2009-07-06T00:00:00-07:00

Having moved to my own domain, I was monitoring traffic to my site on Google Webmasters site. I notices that Google still returned results from my blogger-hosted domain. I wanted people to be redirected to my new domain. Here is what I did:

Blogger > Settings > Publishing > Advanced Settings. Chose to redirect to my sub-domain blog.saicharan.in
In my domain management cpanel > Subdomains, created blog.saicharan.in and added the home directory as my blog directory.
Using the wordpress admin interface, I changed the structure of my blog permalinks to be of blog/year/month/date/title.

Now come the interesting part. While wordpress provided me text to add in my .htaccess, it did not provide the code for redirection. Google helped me add the following line in my .htaccess file that did the trick! RedirectMatch permanent ^/[0-9]{4}/[0-9]{2}/([a-z0-9]+) http://saicharan.in/blog/$1 That did the trick. Thanks to BlogBloke! References: http://www.blogbloke.com/migrating-redirecting-blogger-wordpress-htaccess-apache-best-method/

Default runlevel on Ubuntu

2009-07-01T00:00:00-07:00

Changing the default runlevel on ubuntu was quite different from that of RedHat/Fedora. Ubuntu has no inittab. Instead, I had to rename the S30gdm* and S30kdm* files in /etc/rc2.d/ to KS30gdm* and KS30kdm* (the renaming is just like in fedora).

.bash_profile in ubuntu

2009-07-01T00:00:00-07:00

I updated my .bash_profile in my ubuntu instance but the changes were not getting reflected in my shell. A bit of searching revealed that I have to instead add a new .sh file in /etc/profile.d/ that contained the necessary aliases and updates to my PATH etc. It appears like Ubuntu auto runs all .sh files in /etc/profile.d/ whenever a login session is created. .bash_profile was a lot more personal customization. Wonder how I could this personal customization in ubuntu. Any one any ideas? Let us know via comments. @update: Thanks to manoj for pointing out .bashrc (had forgotton about it). .bashrc does help with personalizing the environment.

Ubuntu sshd

2009-06-30T00:00:00-07:00

#sudo apt-get install openssh-server Done! Simple as that. Ref: http://www.cyberciti.biz/tips/howot-install-ubuntu-linux-ssh-server.html

ld terminated with signal 9

2009-06-30T00:00:00-07:00

Been trying to build substantial amout of code on linux vmware image. Three times the build has failed with "ld terminated with signal 9". A simple google revlealed that I might have run out of swap space! So I run sudo swaon -s and get nothing atall! Then a google for "turning on swap space" got me to do the following: # sudo dd if=/dev/zero of=/moreswap bs=1M count=512 That creates a 512 MB file named moreswap filled with zeros.


# sudo mkswap /moreswap
# sudo swapon /moreswap

Appended the following line to /etc/fstab to make this change permanent. /moreswap none swap sw 0 0 Worked like a charm! Ref: http://www.linux.com/archive/feature/113956

Hello WordPress! My new home online!

2009-06-19T00:00:00-07:00

Migrated to Wordpress. In about 5 seconds. Yup. I am as impressed with the 5-second install as I am with this import feature. The Dashboard > Tools > Import > Blogger option is fantastic. Once with WordPress, I guess I will stay with it for a real long time! Three cheers to WordPress :)

CVS, ViewVC integration with Google Prettify

2009-03-19T00:00:00-07:00

Been wanting to do this for long: browse SVN/CVS via a web interface. Ofcourse, it is a solved problem. But I wanted this set up for my own local CVS repos.

ViewVC to the rescue.

Prerequisites: Python2.x, Apache2.0+, CVS, CVS/SVN Python Bindings.

Detailed installation process:
1. ViewVC:
I have CVSNT on my workstation. So I downloaded ViewVC-1.0.7 from http://www.viewvc.org/download.html (spcecifically, version 1.0.7 from http://viewvc.tigris.org/servlets/ProjectDocumentList?folderID=6004).

To install ViewVC, first unpack it to some folder, run 'python viewvc-install' from the command line, with the current directory as the unpacked directory. I chose all the defaults values when prompted.

Next, I configured viewvc to pick up my repositories by editing the /viewvc.conf file. I changed the cvs_roots and cvsnt_exe_path variables.

2. SVN Python bindings for ViewVC:
ViewVC is written in python and tigris.org provides python bindings to talk to the CVS/SVN repository. This can be got from subversion.tigris.org Documents Area. Be sure to download the version appropirate for your version of python. Simply run the installer. You will be asked to point the installer to the Apache installation directory.

3. mod_python:
You will need to download the mod_python for Apache if you dont have it already. You can check the /modules/ directory. Look for mod_python.so file. If it is not here, download it from here: http://www.apache.org/dist/httpd/modpython/win/3.3.1/ I used this: http://www.apache.org/dist/httpd/modpython/win/3.3.1/mod_python-3.3.1.win32-py2.5-Apache2.2.exe

4. Configuring Apache.
Edit the httpd.conf file to add the following:
a) LoadModule python_module modules/mod_python.so
b) ScriptAlias /viewcvs "C:/Program Files/viewvc-1.0.7/bin/mod_python/viewvc.py"


<location>
AddHandler python-program .py
PythonPath "[r'c:\\Program Files\\viewvc-1.0.7\\bin\\mod_python']+sys.path"
PythonHandler apache
PythonDebug On
AddDefaultCharset UTF-8
</location>

NOTE: The above will work if you have chosen the defaults while installing ViewVC.

Done! Goto: http://your-machine/viewcvs.

However, I got an error when I did this: "ImportError: No module named apache"

So, I tried the alternate approach:
A) Copy <viewvc-install-dir>/bin/cgi/*.cgi to <apache-install-dir>/cgi-bin/
B) Add the following line to the <apache-install-dir>/conf/httpd.conf file:
ScriptAlias /viewvc /cgi-bin/viewvc.cgi
C) Restart Apache.

Done! Go to: http://localhost/cgi-bin/viewvc.cgi
It works for me!! I wish I could fix the other method too.

Good. Now that it works, I should be happy. But I was not :( When I 'view' a source file, it does not do the syntax highlighting (I use CVS with C++/C projects and I was not getting the syntax highlighting for these languages). So what do I do? Wanted to integrate some open source syntax highlighters. I dug thru' the code of viewvc.py and from there went on to find the place where the markup is done. (search the code base for view_markup function. I use RedHat sourcenavigator to browse and read code). They seemed to be using some PHP code to get the job done. However, I remembered I was very happy with Google's Prettify (any code you browse on code.google.com has probably used Google prettify to syntax highlight the code). So I decided to use it.

Also, using the Google Pettify is quite simple:
A) Add the following lines to the "head" section:


<link href="[docroot]/prettify/prettify.css" type="text/css" rel="stylesheet" />
<script type="text/javascript" src="[docroot]/prettify/prettify.js" > < /script >

B) Add "onload=prettyPrint()" attribute to the "body" tag.
C) Put your code in <pre class="prettyprint"> or <code class="prettyprint" >tags.
D) Done!

It took quite some reading of the ViewVC python code to figure out simple ways to do it. Here is my story:
I read thru the ViewVC python code and found that there was a header and footer being used for each page. Then there was a template for markup and each of the different views that ViweVC supports. Then I stumbled upon the EZT class (EaZyTemplates). Just what I needed to integrate with Google Prettify!! So I found the templates being loaded by ViewVC. They are loacated under <viewvc-install-dir>/templates/. Here are my modifications:
1. Download Google Prettify from: http://code.google.com/p/google-code-prettify/
2. Unzip it. Copy the src folder to <viewvc-install-dir>/templates/docroot/
3. I renamed the src folder to prettify (just to help me later)
4. Add the following lines to <viewvc-install-dir>/templates/include/header.ezt, in the "head" section:


<link href="[docroot]/prettify/prettify.css" type="text/css" rel="stylesheet"/>
<script type="text/javascript" src="%5Bdocroot%5D/prettify/prettify.js"></script>

also, modify the body tag to: <body onload="prettyPrint()">
5. Modify <viewvc-install-dir>/templates/markup.ezt:
Change this: <div id="vc_markup"><pre&t;[markup]</pre></div>
to: <div id="vc_markup"><pre class="prettyprint">[markup]</pre></div>

Done!.

Have fun! And post your questions as comments.

NS2 nam error

2009-03-02T00:00:00-08:00

I have been bothered by this error while running ns/nam for a long time now. Finally found that tk needed patching :( Here is the error that I got and the solution that helped me fix it.

Error:
[root@localhost]# nam:
[code omitted because of length]
: no event type or button # or keysym
while executing
"bind Listbox {
%W yview scroll [expr {- (%D / 120) * 4}] units
}"
invoked from within
"if {[tk windowingsystem] eq "classic" || [tk windowingsystem] eq "aqua"} {
bind Listbox {
%W yview scroll [expr {- (%D)}] units
}
bind Li..."

And, I got the solution to this on: http://forums.fedoraforum.org/showthread.php?t=206795.
Essentially you need to patch tk8.4.18 with the patches from: http://bugs.gentoo.org/show_bug.cgi?id=225999

Details of how to patch are available at: http://forums.fedoraforum.org/showpost.php?s=a2bb89875669ff26ed61cd371399a517&p=1131049&postcount=3

Google default language

2009-03-02T00:00:00-08:00

Each time I use Google from office, Google responds in Thai. I fixed that by going to www.google.com/ncr.

Now onwards, I hope to always get results in English :) Btw, if you happen to clear your cookies, you should go to www.google.com/ncr again.

My Reading List

2009-02-17T00:00:00-08:00

Very frequently my friends ask for my reading list. So I decided to follow the DRY and SRP principles to help them and help myself. Hence this blog entry. Here goes: My favourite tech blogs/sites: Programming blogs: 1. codinghorror.com 2. blog.objectmentor.com (this along with its original site at butunclebob.com) 3. thedailywtf.com 4. c2.com --> Advanced stuff. Really interesting though. It takes some time to follow their style of expression - but is definitely worth a shot. 5. Reddit.com In particular, http://www.reddit.com/r/programming/ & http://www.reddit.com/r/technology/ Programming + Technology + Perspectives (my favourite pass-times): 0. news.ycombinator.com 1. steve-yegge.blogspot.com 2. paulgraham.com 3. joelonsoftware.com 4. norvig.com 5. googleblog.blogspot.com 6. TED.com - My personal favorite for advances in human thought and creativity! Tech News: 1. digg.com 2. slashdot.org Management: ( Yeah, I am interested in Genuine management! ) 1. sethgodin.typepad.com PS: I will update this post as my reading list changes (Yes. that includes additions and deletions as well. For deletions, I will keep the links, but the text will be struck off like ~~this~~).

Creating DLLs with MinGW

2008-09-17T00:00:00-07:00

This morning, I was asked how to use existing C code in C++ code. So I took the route of converting the C code into a DLL and then linking to it from the C++ code. So I had to figure out how to do this using MinGW on Windows. Here is an account of my experiments (distilled ofcourse!):
There are three things you need to do:
1. Convert the existing into a DLL.
2. Include the header of the DLL in the sources where you wish to use the library.
3. Build your code, linking against your DLL.

Here are the steps:
a) For this, you need to add the following code to the header file containing the declarations of the functions that are to be used:

#ifdef __cplusplus
#define cppfudge "C"
#else
#define cppfudge
#endif

#ifdef BUILD_DLL
// the dll exports
#define EXPORT __declspec(dllexport)
#else
// the exe imports
#define EXPORT extern cppfudge __declspec(dllimport)
#endif

b) Front of each function that you want to use from the DLL, prepend the word EXPORT. For example:
EXPORT int hello(void);

c) Create the create the object code using the following command:
>gcc -c -DBUILD_DLL TestDLL.c, where TestDLL.c is the source file.

d) Next, use the object code to create the DLL with the following command:
>gcc -shared -o TestDLL.dll TestDLL.o -Wl,--out-implib,TestDLL.a, Note that TestDLL has to be replaced with whatever is the actual DLL name.
>Creating library file: TestDLL.a (This is the output of the command)

e) Now, compile the actual file (note that this file should include the TestDLL.h header)
>gcc Main.cpp -o Main.exe TestDLL.dll

f) Done! Run the executable:
>Main.exe
Hello World!

>

Here are the files that I have used to test these things. I have tested them on Windows XP using MinGW32. I have used the following link for reference: http://www.emmestech.com/moron_guides/moron2.html

Global C++ Exception Handler

2008-07-29T00:00:00-07:00

Just found out that many C++ compilers provide the std::set_terminate() function for catching any unanticipated exceptions. Read here for more: http://www.extinguishedscholar.com/wpglob/?p=176

C/C++ resources online

2008-06-11T00:00:00-07:00

The following is a continually updated list of my personal favorites for C/C++ reference:

C:
C-FAQs: http://c-faq.com/index.html
Overflows in C: http://www.fefe.de/intof.html

C++:
Stanford Library: http://cslibrary.stanford.edu
C++ Coding Conventions(CERN): http://pst.web.cern.ch/PST/HandBookWorkBook/Handbook/Programming/CodingStandard/c++standard.pdf
C++ Casting: http://www.cs.umd.edu/class/sum2003/cmsc311/Notes/BitOp/cast.html & http://www.nacs.uci.edu/dcslib/sun/compilers/c-plusplus/c%2B%2B_ug/Cast.new.doc.html

Wrong Characters being Displayed

2008-06-10T00:00:00-07:00

Had this problem with my keyboard layout getting changed just too often. The problem was as follows: Off and on, my keyboard was behaving erratically. It would mis-behave and then come back to normal. I suspected a change of keyboard layout - I had this problem earlier on my Linux Box and RI pointed out that my keyboard layout was UK English!

So, I too started off searching google for this, and things were mostly pointing to IME/Languages. When I opened the Regional Language Options in the Control Panel, the language bar popped up. I noticed that the language was set to Finnsh. Once I changed that to English, another icon appeared next to it - the Keyboard icon. It was in Finnish. So I changed it to English and all was well. But then I was wondering how these settings were changing so often. SO I went to the Regional Language Options in the Control Panel. Went to the languages tab and clicked on the Details button. From there, I selected the Finnish Language and Keyboard settings. At the bottom there is a Key Settings button. That was the major culprit. Click that button and you will see that Alt+Shift is assigned to "Switch between input Languages" option. I simply removed that key-binding to avoid un-intended switching between languages.

Also, I use the alt+shift combo often in my work - so that was the probem! Now we know! So change your keyboard settings and get back to efficient mode.

One last advice. If you ever face such a problem, make the language bar visible: Control Panel > Regional Language Options > Details > Language Bar Button > Show Language Bar. Once you see the language bar, you can know at once if your keyboard layout is the problem.

ThinkPad T60 TouchPad Scroll in Office 2007

2008-06-10T00:00:00-07:00

Found this link on Google. It was reported as on the day of posting as a possibly problematic site. But I went on and found the info in that site very useful. So here is the link:
http://www.lvlolvlo.net/2007/02/11/office-2007-on-a-thinkpad-ultranav-support-for-scrolling-fix/

VirusRemoval.vbs Windows Script Host

2008-03-27T00:00:00-07:00

Atlast! Got rid of that damn warning.

msconfig did not show up this thing. No amount of standard registry scans helped me find this. I looked at the standard Run, RunOnce & Shell hives under HKLM/Software/Microsoft/Windows/CurrentVersion/. Just no use. No entries that were tell-tale traces of this VirusRemoval.vbs.

But done at last! Took some patient Google-searching though. Some kind soul had provided the entire code of the VirusRemoval.vbs script file at:
http://www.thinkdigit.com/forum/showthread.php?t=71097. Looking at the code was enough to tell me where the virus had made entries in the registry.

Goto: HKLM/Software/Microsoft/WindowsNT/CurrentVersion/Winlogon. Under that, you will find a key called Userinit. Double click that key. A dialog box will open up with a string parameter. Edit that to remove just the offending entry. Warning: If you are not sure what the offending entry is, DONOT modify the key. Please post back the contents of the key here, and we could work out something!

After cleaning up my registry, the value of Userinit for me is: C:\WINDOWS\system32\userinit.exe

Good Luck!

Install RPMs on Ubuntu

2008-03-19T00:00:00-07:00

Check this link. It describes the use of a tool called 'alien' to install RPMs on Ubuntu linux!

http://theunixgeek.blogspot.com/2008/03/why-i-switched-back-to-ubuntu.html#c2746545558233032385

yum ntfs-3g

2008-02-16T00:00:00-08:00

To install ntfs support for Fedora linux, use the following as root: yum install fuse fuse-libs ntfs-3g reference: http://www.mjmwired.net/resources/mjm-fedora-f7.html#ntfs

Adobe Reader Commenting Not Allowed

2008-02-06T00:00:00-08:00

At last! Wanted to allow my prof. to be able to comment the pdf files that my LaTeX produces. But, even though I was NOT setting any such restrictions in LaTeX, the Adobe Reader always showed that Commenting was not allowed. After a Google search, I got this post in the Adobe Forums: http://www.adobeforums.com/webx/.3c05f5b1 In short: You cannot comment unless explicitly permitted. For this, you need to get to Adobe Acrobat (not the reader), and set the permission from: Commenting > Enable for Commenting in Adobe Reader. Then you will be allowed to comment or markup :) Update: If you don't mind a few additions of Foxit, you might want to try Foxit reader(www.foxitsoftware.com) for commenting your PDF documents without any of the above hassle.

WIndows Script Host: Unable to open file

2008-02-04T00:00:00-08:00

For quite some time a lot of my friends kept getting a windows script host error whenever they tried to open a drive. It says: Windows Script Error: Unable to find file: "....vbs". Spending some time on google led me to this site: http://www.mydigitallife.info/2007/04/19/unable-to-open-hard-or-usb-flash-drive-with-windows-script-host-cannot-find-script-file-autorunvbs-error/ All we need to do is to either delete the autorun.inf file there or modify the content in to get rid of the offending startup file info. To delete the file: del:\autorun.inf /f /s /q /a To modify the file, first remove its hidden-file attribute: (see http://forums.techarena.in/showthread.php?t=717194) attrib -s -h -r:\autorun.inf Go ahead and edit this file now.

TeXnicCenter and Adobe Reader 8.0

2008-02-04T00:00:00-08:00

I recently upgraded my Adobe Reader to version 8. The new interface is cool and all that, but I had an issue with using TeXnicCenter. Whenever I view a compiled document from TeXnicCenter, and then closed the Adobe reader or recompiled the file (causing adobe reader to close the document), the Adobe reader was crashing. A Google search yielded the following link which is very useful. It is almost a text-book type of solution which just works! http://dikkie.net/2007/02/16/texniccenter-and-adobe-reader-80/

Why is switch case better than if else if?

2008-01-28T00:00:00-08:00

Why is switch case better than else if? Or is it? Here is some code I got into trouble with: . . . if(dim==0){ ...//do lots of things ...return; } doSomeCommonThingsHere(); if(dim==3) ...doSomething3(); else if(dim==4) ...doSomething4(); else if(dim==5); ...doSomething5(); doSomeMoreCommonSomethings(); . . . See anything? I did not, initially. The semi colon after else if(dim==5). How I unearthed the bug? GDB was crashing. So no debugger to help me:( I figured out that only the dim==5 case was working well - and that none of the cases above it were working correctly. So I considered moving one of the earlier case code to the end to see if I can figure out the problem. While moving the code I accidentally noticed the semi-colon. Man! Computers are dumb - or was it me dumb? Now did say switch case might have been better? Maybe. Because we are taught to put the break; statement at the end of each case to prevent it from falling-through right? What if I forgot to put the break; ? I guess it is easier to "find" a missing break than a missing ;. Did you see the semi-colon after missing? Now why did I use such a large number of if-else-if statements? I was using "Incremental development". I did not see the other cases coming in hordes. Shortsighted you might say, but I did not even intend to do the other cases in the first place. WOW! How easily changing requirements can screw up such wonderfully working code. Screw the changing requirements. Now you see how difficult is the job of a designer - he has to really think of extensibility - see extensibility in a new light? Consider for a moment the above code. I was actually telling the computer to do things wrong!!! When will these computers learn to understand (:D) Or will they ever?

MinGW GProf with Eclipse 3.3 (Europa )

2007-09-14T00:00:00-07:00

To use MinGW gprof with Eclipse, in the project settings, under complier, enable the gprof option. Further, in the Linker section, under command line, add -pg to your list. Build the program. Run the program and check that the gmon.out file has been created. You can run gprof as follows: gprof.exe. You can run gprof from within eclipse by configuring the external tools: 1. Open the external tools dialog 2. Double click on program to create a new program configuration 3. Give this profile a name, eg. gprof 4. In the location text box, give the FULL path to the grpof command 5. In the working directory, choose: ${workspace_loc:/path/to/executable} 6. Arguements: ${file_prompt} ${GMON}, where GMON has been assigned the path to the gmon.out file using the variables button. References: 1.http://publib.boulder.ibm.com/infocenter/systems/topic/com.ibm.aix.cmds/doc/aixcmds2/gprof.htm 2.http://gcc.gnu.org/ml/fortran/2006-11/msg00217.html

ब्लोग्गीं, और हिंदी मे!

2007-04-18T00:00:00-07:00

हेल्लो वर्ल्ड! गूगल ki गूढ़ विल से हिंदी मे ब्लोग करना बहुत आसान हैं। इस फेतुरे के लिए शुक्रिया!!! लव यू गूगल! कीप उप थे गूढ़ वर्क! Please excuse my rustic hindi...I was just experimenting :) If you are unable to read the Hindi correctly, then please read this article on enabling Indic fonts for various OSs: http://en.wikipedia.org/wiki/Wikipedia:Enabling_complex_text_support_for_Indic_scripts

Routing and Remote Access Service Fails!

2007-01-27T00:00:00-08:00

This afternoon, we were suddenly unable to browse the internet. Suspicious about the proxy server being down, I checkout from our main browsing computers. I was able to ping the students proxy. A little more digging up led me to figure out that there was something wrong with our lab router that handles the internet traffic to the student's proxy; the main browsing systems bypass the router. I disabled the routing service and set it up again. Though the routing service itself did not throw up any error, the event log had logged the error message. I was unable to browse even from the router itself. Also, the IIS server on the router also failed. I restarted the system thinking it might help - but to no avail! Checking the event log revealed that the Routing and Remote Access service had thrown up an error - Unable to add the internal adapter to the routing service - incorrect parameter. Looking at the event log messages for a few hours earlier, I hit upon a message saying that a duplicate name had been detected on the network. I then realized that this was quite likely since our server had a name Dell1, which was quite possible to be duplicated over the network since there were a plethora of Dell machines springing up here. So I renamed our machine and restarted - Bingo! it was running like a good ol' boy! Lesson to be learnt: Event log is Holy Grail!.

Now, thats a Palindrome...

2006-12-16T00:00:00-08:00

Now that is a palindrome: A man, a plan, a canoe, pasta, heros, rajahs, a coloratura, maps, snipe, percale, macaroni, a gag, a banana bag, a tan, a tag, a banana bag again (or a camel), a crepe, pins, Spam, a rut, a Rolo, cash, a jar, sore hats, a peon, a canal -- Panama! From Common Lisp, the Language (2nd ed). And now, this is a geek: http://www.norvig.com/pal2.html and this is a palindrome: http://www.norvig.com/pal1txt.html Read more at the Google Blog.

Subclipse Proxy Configuration

2006-12-14T00:00:00-08:00

Whew! That was a real big deal. I wanted to checkout the newly open-sourced Google Web Toolkit using Eclipse via the Subversion plugin. I work behind a proxy and have a choice of three proxies offering varying capabilities and restrictions - some require authentication while others don't. When I tried checkout, I was in for a real surprise - I was getting an error message saying Error 407: Proxy authentication required. Since I did not set any proxy in the first place, I was wondering how a proxy was picked up and why I was not being prompted for authentication! When I searched the Eclipse preferences dialog for SVN, I did not find any place where I can set up a proxy. Also, I wondered if Subclipse had somehow chosen to use my Windows default proxy configuration. So, I went to Control Panel > Internet Connection > Connections > LAN Settings. Nope, the default proxy that I had configured for my windows was different from the one that Subclipse was using - the default proxy did not require authentication while Subclipse was trying a proxy that required authentication. Exasperating! Just wanted to be sure which proxy was being used. As usual, the Ethereal network protocol analyzer came to my rescue. I figured out that by default, Subclipse had chosen a proxy that needed authentication (I am yet to find out how it found the proxy address in the first place!) and had not prompted me for authentication. Then, a search through Eclipse help led me to this link: http://svnbook.red-bean.com/en/1.1/ch07.html#svn-ch-7-sect-1.2. In short, I had to edit the registry to set my proxy - call that user friendly??? Well, since most of the time people who check out code are geeks, may be I should excuse this!!! Here is where I had to go: HKCU\Software\Tigris.org\Subersion\Servers\Global\http-proxy-host and http-proxy-port values. Once I set up the proxy there, all worked well. Whew!!! Breathe easy now :)

Testing the RAM for defects on Windows

2006-11-29T00:00:00-08:00

Somebody had asked me to look at some problem being created by Ulead DVD Factory 10.0. The error reported was some failure to read a memory location. This message repeated for Nero also, after a few days. I suspected faulty RAM, after seeing the log. The message was EXCEPTION_ACCESS_VIOLATION. But, I did not know the right tools for testing the RAM. So, a Google Search led me to the following tools: 1) MemTest 2) Microsoft's Windows Memory Diagnostic. I did not test Memtest, but I used the Microsoft solution. It was easy to use, but the UI is not for the layman. Notes: - Please keep a floppy disk handy. If you are one of those forward looking geeks, and do not have a floppy drive, you need to have a CD writer. Check out the details provided here for working with a CD. - After you run the program and have created a floppy, boot from the floppy. - To run Advanced Diagnostic tests, hit the T button on your keyboard.

Sorting Algorithms : A visual treatment

2006-11-20T00:00:00-08:00

Check out this link at: http://netlib.bell-labs.com/cm/cs/pearls/sortanim.html It is from the Programming Pearls site. Gives some insight into the working of the algorithm. Check the behaviour of different algorithms on different inputs. However, it would be more helpful if we also have some control over the speed; this will help the visualization better! Let me see if I can fix that recipe (ofcourse, I will start with the SortAnim.java provided at the site).

Eclipse Update behind a proxy

2006-11-18T00:00:00-08:00

Updating Eclipse from behind a proxy was quite counter-intuitive for me; or was it??? I had expected to find the proxy setting in the same window where the updater hooks up to the internet. Unfortunately, with Eclipse, it was under Window > Preferences > Install/Update > Use HTTP Proxy... But this option of not having to hunt around the eclipse site for the plug-ins is a real killer concept. Saves a lot of time too. One up to the Eclipseproject.

Installation of Sun Studio 10 on Sun Solaris Machine

2006-11-16T00:00:00-08:00

1. First uninstall the existing version by typing:

 - cd /var/sadm/prod/com.sun.studio_10 - Run the batch uninstaller. - Further info on uninstalling can be found at: http://docs.sun.com/source/819-0485/remove.html

2. Next, put the Tar file in the directory in which you wish to install. Untar it. Keep the tar file in the same directory as the installer file. 3. Run the installer and follow instructions.

Windows XP Pro: Network access: logon failure

2006-11-15T00:00:00-08:00

Windows XP Pro: Network access: logon failure: the user has not been granted the requested logon type at this computer Solutions: 0) Start > Control Panel > Administrative Tools > Local Security Policy > Local Policies > User Rights Assignment: - Goto : Deny Access to this Computer from the Network - Remove the user name to whom you wish give permission to access the computer over the network. 1) Just run the network setup wizard and turn on file and printer sharing. If that does not help, try the next link: 2) http://www.experts-exchange.com/Operating_Systems/Windows_Server_2003/Q_21072962.html?qid=21072962 3) http://www.experts-exchange.com/Operating_Systems/Windows_Server_2003/Q_21072962.html

Windows : Autorun is Disabled?

2006-11-15T00:00:00-08:00

Here is a solution for the Geeks; it modifies the Windows registry:

  1. Start RegEdit (regedt32.exe).2. Go to HKEY_LOCAL_MACHINE/System/CurrentControlSet/Services/Cdrom.3. Edit the Autorun value to '1' to enable autorn, and '0'   to disable autorun.4. Close RegEdit.

NOTE: You may have to restart the system. A simpler solution (not guaranteed to work if autorun has been disabled in the registry, as in my case) is:

  1. Right-click on the drive.2. Choose properties.3. Choose Autoplay.4. Choose the action you want to take for various file types.

VMWare : SSH access to RH9 from Windows using PuTTY

2006-11-15T00:00:00-08:00

Refer to my previous post regarding setting up Internet access via RH9 Guest OS. Make sure you have similar settings. Then, just change the firewall settings to allow incoming SSH connections. Nothing else needs to be done.

VMWare : Sharing Files by Connecting to Windows from Linux

2006-11-15T00:00:00-08:00

Check out this link from VMWare Documentation: http://www.vmware.com/support/gsx3/doc/running_fileshare_lin2win_gsx.html#1089626

VMWare : Internet / FTP / Telnet Access to Linux Guest from Windows Host

2006-11-15T00:00:00-08:00

1) After installing VMWare workstation or VMWare Player, find out the IP Subnet of the VM Network Adapter named VMNet8. This is the VMAdapter that is used for NAT connectivity. 2) Set up the Linux host's IP address to be in the same IP Subnet as VMNet8. Just make sure that you donot use the IP addresses subnet.1 OR subnet.2 Subnet.1 is used by VMNet8 while subnet.2 is used as the IP of the NAT Gateway. (Refer to VMWorkstation documentation for more details). 4) Set the default Gateway to subnet.2 3) Set up VMWare to use Ethernet in NAT mode. 4) Done.

VMWare : Internet access from Guest VM (RedHat 9)

2006-11-15T00:00:00-08:00

You donot need to create any internet sharing in windows etc. VMWare will take care of that for you.
To set up internet access from the guest VM, set the VM to use NAT for ethernet.
Set the IP address to the same segment as that of VMNet8. (just make sure that it is not .2).

Now you can access the Internet from the Guest VM!

VMWare : Do's & Donts

2006-11-15T00:00:00-08:00

VMWare by default creates two Vitual Network Adapters: VMNet1 & VMNet8.
VMNet1 is useful for host-only connection.
VMNet8 is for NAT access.
Donot change the IP domains which are assigned by default. You could wreck the DHCP, DNS & Routing domian that VMWare creates.
To change these settings, please use: Edit > Virtual Network Settings > NAT.
By default, the IP Address .2 with the VMNet8 segment, is the IP address of VMWare's DNS & router.

Using Minix on VMWare

2006-11-15T00:00:00-08:00

There is nothing special that you need to do incase you need to run Minix on VMWare. Infact, you can download the VMWare ready image of Minix from here. Only, this image is not allowing ftp access to VMWare. After much effort, I found an image file for Minix 2.0.4 which was consolidated. The website is so confusing. It does not specify clearly what needs to be downloaded and they have lots of things there too!!!
To allow ping to work, just set up NAT as described here.
Read this post or this post to enable FTP and Telnet access to Minix.

Samba Server Setup

2006-11-15T00:00:00-08:00

Check if the Samba server is installed: You can check this by going to Main Menu > System Settings > Server Settings > Services. Then, look for a service named smb. If it is present, that means, the Samba server is installed. If it is not started, start it up. If you donot have the Samba server installed on your system, you should install it from the RedHat 9 CDs. The server along with the GUI to configure Samba are present on CDs 1, 2 & 3.

- Insert CD1.- Go to the CDROM and navigate to RedHat > RPMS.Here, look for a file called samba*.rpm. Install it.- Insert CD2. Navigate to RedHat > RPMS.Install a package called redhat-config-samba*.- Insert CD3. Navigate to RedHat > RPMS.Install a package called samba-swat*

NOTE: SWAT is a browser based configuration tool for Samba. It talks be default on port 901. So, to use this, httpd should be running on Linux and the firewall should not block this port.) We will use the GUI rather than SWAT for configuration.

Go to the command prompt and type: /usr/bin/redhat-config-samba (it is in /usr/bin folder).
Login as root.
You will get a screen similar to the one shown here.
Go to Preferences > Server Settings. The default settings are shown here. I had to keep the group to something different from what was the Workgroup on my Windows system. Give a nice description; this is what people from other systems will see as the title for the Server (eg. In Windows, in the My Network Places, Show Work Group Computer, this is what will be seen.)
On the Security tab,

- set the Authentication Mode to User.- set the Encrypted Password to Yes.- set Guest account to the user for whom you are setting up this share.(I donot as yet know how to allow for anonymous shares...)- click OK.

Go to Preferences > Samba Users.

- click add.- Select the Unix username for the user whom you want topermit to use the share. When he logs in, he will be takent to his homedirectory unless some other shared folder has been specified.- If the user is logging in from Windows, provide his Windows username

(this simplifies authentication and hepls to map Windows users to Linux users, I think so, I am not sure about this part).

- Provide a password (preferrably different from his Linux login password).- click OK.

Click Add, and add a shared folder to allow access from outside the Linux machine.
To access this share from Windows, Go to My Network Places > View Workgroup Computers > Microsoft Windows Networks. Go to the appropriate workgroup that you had specified earlier. Here you will find the Samba Server with the description you provided earlier. Open this Samba and there you go!!!

Now someone please tell me how to access the Windows Shares from Linux. Any help would be appreciated. :) UPDATE: Okay, just discovered that File & Printer Sharing must be enabled on Windows for accessing the Shared Files! For this, please run the Network Setup Wizard with appropriate options!!!

Networking Lessons

2006-11-15T00:00:00-08:00

Subnets, Non-routable IPS: Learner's Perspective - http://www.easydesksoftware.com/news/news28.htm Admin's Perspective - http://www.pku.edu.cn/academic/research/computer-center/tc/html/TC0000.html Admin's Perspective - http://www.pku.edu.cn/academic/research/computer-center/tc/html/TC0305.html

Network Access across a router

2006-11-15T00:00:00-08:00

This document recapitulates the tasks that were needed to be done by us to enable access between the online and offline systems in the lab at my hostel: 1) First set up a DNS ( with a domain name say ssshcc.edu ) - Set up the forward and reverse lookup zones 2) Set up the DNS machine to act as the router also between the two segments. 3) For each computer on the online and offline segments, change the primary DNS suffix of the computer to the DNS domain name ( as specified in step 1 ) - Right Click My Computer > Properties - Computer Name - Change - More - Type in the new Primary DNS Suffix 4) For each machine in the online and offline segements, make sure that the guest account is allowed network access. - Start > Control Panel > Local Security Policy > Local Policy > User Rights Assignment > Deny Logon over Network - Remove the Users whom you wish to allow network access (if the name is in the list) 5) Make sure that the default gateways and Primary and Secondary DNServers are correctly entered in the Network Configuration. 6) In the lab, i.e., in the SSSHCC, the online systems donot have guest login interactively, but we want the guest users from the offline segement to be able to access the online systems. For this, we enable the Guest user account on the Online systems, but prevent their Interactive Login as follows: - Start > Control Panel > Local Security Policy > Local Policy > User Rights Assignment > Deny Logon Locally - Add Guest user. 7)Here, you can choose the custom list and add the required IPs or choose then Any computer option as required. 8) One last setting: The windows firewall by default allows only computers on the same segment to access each other. This needs to be changed: It is like this: Port 445 (which is what windows uses for file and printer sharing) by default accepts connections only from computers on the same subnet as itself. This behaviour can be changed as described in the document: https://docs.google.com/View?docid=ajgs46pc346b_9dxvvjc. You can find Microsoft's description of the solution(KB840634) at http://support.microsoft.com/kb/840634

Minix - FTP & Tlenet Access

2006-11-15T00:00:00-08:00

I had a problem accessing my Minix VMWare guest OS, via FTP or Telnet. Here is how the problem was solved... A little bit of history: Yesterday, I had to set up a RedHat 9 Guest OS for one of my faculty members. I realized that even though telnet was installed and running, I was unable to access it even locally!!! Then I realized that I had to edit the 'telnet' file in /etc/xinetd.d to allow incoming telnet connections (inspite of changes to the firewall configuration to allow incoming telnet connections). Back to present: So I realized that perhaps something similar needs to be done even with Minix (after all, it is a variant of Unix and must have similar security features!!!). But, when I went to the /etc folder in Minix, I found no xinetd.d folder. Looking around, I found the serv.access file. Guessing that it must be the right place to look, I opened it. Bingo! There it was. Only, I had to decipher how the entires should look like in that file. Ever so helpful, a comment asked me to man serv.access. Also, I looked at the /usr/adm/log file. It was all there - all those access denied messages... Initially, my /etc/serv.access file was like this: # /etc/serv.access # 2006-05-21 # See the serv.access(5) man pages to learn how to edit this file # to make your system safe on the network. # this is insecure! replace with something more specific asap telnet ftp: +* log; # this is better, keep outsiders out # telnet ftp: +*.local log; # this records all unsuccessful access attempts in/usr/adm/log *: -* log; After a reading the man page and a little tinkering, I changed the line "telnet ftp: +* log;" to "telnet ftp: + log;". i.e., I just removed the *. May be very insecure, but it does the job for me. Perhaps one could add an IP address or a range of IPs to enhance security (as described in the man page). One another word: This might be very helpful on the VMWare front: I am still using NAT. I had to just set the IP address of my Minix to be on the same subnet as VMNet8 (which is the default subnet on which VMWare does NAT-ing). Also, the default gateway on the guest OS - Minix - had to be set to VMNet8-subnet-.2 ( The .2 IP is the gateway across which VMWare does NAT). Thats it!!!. All works fine now...

Matlab license manager error: Solaris 10

2006-11-15T00:00:00-08:00

If the Sun Machine is not properly shut down when Matlab (license) server is running, you will be unable to start matlab after the reboot. You will get an error -15. To trouble shoot, I did the following: - I knew that lmstart command present int $MATLAB/etc directory starts the matlab license manager. - To start the license manager (i.e., to run the lmstart command), you need to be logged in as a non-root user. - So, I tried to start the license manager. - I got a message saying that I needed to delete some files: /var/tmp/lm_*.log and /var/tmp/lm_*.dat - For this you need to log in as root. - Once this is done, run lmstart again. - Done.

Linux : Mounting a USB device - made simpler

2006-11-15T00:00:00-08:00

1) At the terminal, log in as root. 2) Open the /etc/fstab file for editing. 3) Append the following entry to the file: /dev/sda1 /mnt/usb autofs 0 0 4) Start > System Tools > Disk Management 5) Select the device to be mounted and mount. NOTES: 1) /dev/sda1 is the name of the device whose file system you want to mount at /mnt/usb (this too is your choice!) 2) autofs tells the mount command that the filesystem type should (attempted to) be detected automatically. If you want, you can explicitly specify a file system. 3) In the options, DONOT specify the kudzu option. The kudzu option will cause /etc/fstab to be updated when the usb device is unmounted or unplugged. Thus, the entry will vanish after this. For more information regarding kudzu, use man kudzu at the terminal. 4) In the options, please specify user and NOT owner. If you donot specify user, the DiskManagement will not show the USB device if this is launched by a non-root user (by default). The GUI for DiskManagement is actually a command called usermount that reads from /etc/fstab and displays a list. Hence, if user is NOT specified, the device will not show up in the list. Further, the user option indicates that ANY user can mount this device!!! 5) For convinience, the DiskManagement can be added to the launcher panel (Start > System Tools. Right Click on DiskManagement and click on Add to Launcher Panel)

FTP Server on Windows 2003 Server R2

2006-11-15T00:00:00-08:00

We had set up IIS on Windows 2003 server. Along with HTTP, we also had to set up FTP server to allow our staff members to be able to upload info to their respective folders. The initial set up worked, but it was readonly, inspite of the folder permission being write. Then, I checked out that if I logged in as admin, I could create folders! So, I went to check out the folder permissions for the admin account. It was exactly as I had configured the staff account (FULL CONTROL), except that the permission were only for the current folder. For the staff account permissions, I had chosen to give full control to "This folder, and subfolders and files(as intuition and common sense would have served anyone). But, I must confess that I donot fully understand the NTFS permissions structure. So, I changed the staff permissions to this folder only and bingo! it worked.

Excellent, free iCal Calendars

2006-11-15T00:00:00-08:00

This is a log of my adventures with iCal Calendar clients and format. I tried Outlook Calendar & Google Calendar. Both were good. But, when I tried Google Calendar, it was in the offing and so I could not get much out of it. It was good but was accessible only when on the net. So, I hit upon Rainlander. It was good, it integrated with Outlook and also understood the iCal format. But, I wanted to fill out just one calendar and use it on any client - both application and web-based. So, I filled out the Google Calendar (whew, that took really long!). Then, I realized that I could not actually use it anywhere else at that stage of development of Google Calendar. So, I again filled out the Outlook calendar (because I had read this time that I can use the outlook2ical utility, which is free!!!). Bingo, I used the outlook2ical utility and could export my Outlook calendar to the iCal format which is widely supported. Next, I experimented with phpicalendar using the .ics file that I exported with outlook2ical utility. It is cool and easy to use (as long as I had XAMPP with me, I had nothing to worry!)

Changing the default command for RedHat8 Launch Panel

2006-11-15T00:00:00-08:00

For accessing the Windows Network using Samba, only Nautilus seemed to be understanding the smb:// protocol. I did not want to each time start a terminal and type nautilus to start Nautilus. So, I wanted to add a launch panel icon. I could not find a way to add and configure a new icon. So I dragged the Help icon from the Main Menu and modified its Properties to run the command /usr/bin/nautilus. But this by default opened my home directory. I wanted it to open smb://Hostname. I had experimented earlier at the terminal and found that nautilus took as its command line arguements the location to be opened. So, I changed the command to /usr/bin/nautilus smb://Hostname. This worked well for me. But, I wanted some more sophistication. I wanted to log in directly since smb:// (like ftp://), takes the username and password separated by a colon followed by @ and the hostname. So, I changed the command to /usr/bin/nautilus smb://User Name:Password@Hostname. Nut, commandline did not parse the space separated user name (which Windows allows). So, as an additional change, using my instincts from my working with Linux, I enclosed the User Name within single quotes. This worked well. Similar strategy is also required to be used with the password if it contains spaces. Remember that while typing the username and password in the address bar of nautilus or at the Properties panel of the Launch Panel, the Password in NOT masked. So, it is at your risk that you do this. So, all said and done, here is how the command looked at the end of the experimental session:

/usr/bin/nautilus smb://'User Name':'Pass word'@Hostname

C Tidbit

2006-11-15T00:00:00-08:00

The assignment operator returns something! In the case of a character, it returns the character that was assigned. So, it is useful to write code this way: while ((to[i] = from[i]) != '\0')

Adding a Favicon

2006-11-15T00:00:00-08:00

Check out this Wiki article : http://en.wikipedia.org/wiki/Favicon

The Best GDB tutorial....

2006-04-20T00:00:00-07:00

Once again, GDB comes to my rescue. Preparing for some exam, I need to debug. I need some advanced debug commands. Man pages are too long and do not provide examples. So, where do I go? To where I always went for GDB. To Peter Jay Salzman's web site tutorial ofcourse! It seems to have been recently updated and it is great. Very technical and yet understandable too! - a rare combination. It is still under massive reconstruction as the web site puts it, but still great to go. You can find his homepage here and his usful linux notes here. He seems to use all those things that I am interested in (kind of one-stop for me!), except that I use Matlab while he prefers Mathematica. His LaTeX links are here. And hereis his list of hackers (both good and bad as he puts it.)

What the hell is that service?

2006-04-16T00:00:00-07:00

Two days ago, my system became damn slow. Then, I started looking at the processes and services running. Then, I Googled them and found these amazing sites: http://www.liutilities.com http://www.processlibrary.com http://www.auditmypc.com For my own quick reference, here is the list of the processes that were running on my machine; now, most of them are scrapped. BTW, my machine is now like a tuned string, waiting to be played with. *) Bonjour: Apple Computer's *) vptray : Symatec AV VirusProtectionTray *) qttask : QuickTime Task *) cftmon :The cftmon.exe process is a component used in MsOffice to perform language related functions. It is closely tied to the 'Language Bar' present in MsOffice, so if you use the Language Bar you should leave this process running. If, on the other hand, you do not use the language bar, you should terminate this process to free up system resources. *) igfxtray.exe is a process which allows you to access the Intel Graphics configuration and diagnostic application for the Intel 810 series graphics chipset. This program is a non-essential system process, and is installed for ease of use via the desktop tray. *) Intel hotcommand hkcmd.exe is installed alongside Intel multimedia devices and allows configuration and diagnostic options for these devices. This program is non-essential process to the running of the system, but should not be terminated unless suspected to be causing problems. *) vsmon.exe is a processs associated with the ZoneAlarm personal firewall. It is used to monitor Internet traffic and generate alerts depending on the security rules configured by the user. *) Adobelmsvc.exe is a process which belongs to Adobe Acrobat. This program is non-essential process to the running of the system, but should not be terminated unless suspected to be causing problems. *) mdnsresponder.exe is a process associated with "Bonjour for Windows" software. It is used by ITunes for music sharing. This is a non-essential process. Disabling or enabling this is down to user preference. *) mdm.exe is associated with Microsoft Windows process debugging system. It allows the user to debug Internet Explorer errors by using a script interface tool. This is a non-essential process. Disabling or enabling this is down to user preference. Note: is also a process which is registered as the Win32.Lydra.a information stealing Trojan. This Trojan allows attackers to access your computer, personal data and information. It is a registered security risk and should be removed immediately. *) AcroTray.exe is the Acrobat Assistant used when you print your documents to a PDF. While converting documents to a PDF this process should not be removed. *) Adobelm_Cleanup.0001 is a process which belongs to Adobe Acrobat. This program is non-essential process to the running of the system, but should not be terminated unless suspected to be causing problems. *) lsass.exe is a system process of the Microsoft Windows security mechanisms. It specifically deals with local security and login policies. This program is important for the stable and secure running of your computer and should not be terminated. *) Scrss.exe is a process which is registered as the HacDef-R Trojan. This Trojan allows attackers to access your computer, stealing passwords, Internet banking and personal data. It is a registered security risk and should be removed immediately. *) smss.exe is a process which is a part of the Microsoft Windows Operating System. It is called the Session Manager SubSystem and is responsible for handling sessions on your system. This program is important for the stable and secure running of your computer and should not be terminated. *) PSNGive.exe is a process associated with the lite version of Post-it Note from 3M. References: http://www.auditmypc.com http://www.processlibrary.com http://www.liutilities.com

Lookout - Outlook!!

2006-04-16T00:00:00-07:00

Here is where I again had a hell lot of problems. I wanted to make a birthday calendar and export it in the standard iCal format to my Google Calendar etc, as iCal was hailed on the web as the defacto standard for calendars. I started with Sunbird 0.3a1. Thinking that I could export things in iCal format, I filled in all the birthdays I wanted to. And, then I found that all I had done was a waste. It only allowed me to export selected items as iCal. Thinking that maybe the default format for the calendar is iCal, I looked in my profile directory and bingo! nothing like *.ical, *.vsc or *.vcal. Then the Mozilla Foundation's documentation told me that from this version of sunbird, the default file format was .sdb, some SQLite format. Gone waste was my effort. Lesson #1: Always look for the existance of the features you need in the s/w you choose. So, what do I do? Google it ofcourse! This is what Google yielded and had some good reviews too: http://outlook2ical.sourceforge.net/ It was some VB script. Things went cool till I exported the calendar and imported it into Sunbird. The recurring events which were supposed to recur every year once were recurring every day for a month! Give up? Lesson #2: Never trust feature description. Check out the features ur self. What next? I wanted to somehow get this b'day business running, so I filled out the calendar in Outlook (for the simple reason that it was faster to add in Outlook than in Sunbird, donno why). Then, I bumped into this: http://www.rainlendar.com. A very cute utility that seamlessly integrates with Outlook (oh my God!), reads from and understands iCal files! Thought this was a jackpot. Installed the software and loved its interface and cool features. Under the config > Plugins, i checked the Outlook option and refreshed the rainlendar on my desktop, it began showing the bithdays on the CORRECT days and onMouseOver(), it displayed the subject and description in a pop-up! Cute piece of work. Next, I wanted to take this calendar of outlook to my workplace. How? I chose Calendar. Then I said File > Archive. I saved only the Calendar to an archive.pst (which was non-empty (~256 kb) ). Then I closed Outlook and made another copy of this file. Next, on my Win XP with Outlook 2003, I found the archive of the current Outlook files here C:\Documents and Settings\%USER_NAME%\Local Settings\Application Data\Microsoft\Outlook\Outlook.pst Just to see if I can import, I changed the name of the file from Outlook.pst to OldOutlook.pst. As expected, Outlook did not open saying it could not find the file Outlook.pst; but, it gave me file open dialog where I chose the archive.pst. Then agagin it gave some error and closed. The next time I opened Outlook, it opened, but there was nothing there. So, I decided to import the stuff. I chose File > Import and Export > Import from another file or program > Personal Files Folder (.pst). Here I chose the backup file of the Outlook.pst that I had made earlier (did not want to take any chances with my calendar!). Then, I chose to import the calendar and hit the Finish button. Done! I opened my calendar on the left tab and yo! the birthdays were there!!! Okay, so much so far, but not good enough for me to export to iCal yet. Anyone ne ideas? Please lemme know.

Installing Mandrake Linux

2006-04-16T00:00:00-07:00

The other day, my one of my friends had a problem installing Mandrake Linux. On first thougts, I thought I would get an image aided tutorial ready, but then, I checked out the all resourceful Google and found these. The second link is classic: http://member.melbpc.org.au/~parsonsd/linux/Mandrake10_Install.html http://www.mandrake.tips.4.free.fr/install100.html So, happy Mandraking!

Firefox extension updated!

2006-04-12T00:00:00-07:00

At last! The SaveURI 0.1 for firefox is ready! Now I can breathe easy. It is available here. Try it and post your comments. As I said earlier, this extension is useful for "remembering" the URL of every page that you visited and saved. This is still in beta as it has only just been submitted to Mozilla Foundation for review. Cheers! Now I can do something else while I wait for the review. :) Update: Yesterday, the Firefox 1.5.0.1 running on my system said I needed to upgrade, on saying go ahead, it checked my extensions for compatibility and said SaveURI is incompatible with 1.5.0.2! Anyway, later, I downloaded FF 1.5.0.2 from Get Firefox and installed it. Then, I installed the SaveURI extension and it works just right! Any ideas? Buzz me. Update: This morning (20th April), SaveURI 0.3 was ready. Queued it up for approval at the MDC. Waiting for their approval. If you want to try it, it is available here. Try it and let me know.

Welcome!

2006-04-10T00:00:00-07:00

Welcome to my (b)log. Here, I will be recording my experiments with Computers & Computing.

Post-it notes for the PC

2006-04-10T00:00:00-07:00

That is one hell of a software for forgetfulls like me. You can cover your desktop with post-its and even set off an alarm on specific notes!. Terrific! You can download the lite version from here. You can try the newest version for 30 days from here. Beware! version 4.2 needs .Net framework 1.1. You can get that here. The maker is father of paper-post-its -- 3M.Three cheers to 3M!

New Firefox Extension

2006-04-10T00:00:00-07:00

Today, SaveURI- a firefox extension that I wrote is ready. It was a litte difficult to get things going, but it was fun. By the way, this extension simply saves the URI or URL of every page that you save so that you don't have to search for the parent site link. This was a problem I had for long, especially when I was doing my master's project. The links were just not available on any of the pages that I had saved. I needed them all for my report references. I am glad I could solve my own problems. You can download the extension here. Just be careful if you are using the CustomizeGooogle extension as SaveURI is in the test phase and WILL clash with the latter extenssion.

Sai Charan

Anyconnect VPN on Ubuntu x64

Quest for a good Antivirus

Reading on the Internet

Default runlevel on CentOS

Ubuntu 11.10, PuTTy, tmux & UTF-8

Gitweb with 'side-by-side' diff

Richard Stallman & Steve Jobs

Here's to the Crazy Ones

Steve on Courage, Heart and Intuition

Remembering Steve Jobs

Texnic Center error 'pdflatex.exe: Could not Initialize GUI'

quote: You want to know how to do it

Jekyll feature: Retain Modified Time Stamp

URL Selection in Putty

Tributes to Steve Jobs

When GOD called Vic Gundotra

When Steve Held Open the Door

Static Blog Using Jekyll

Migrating to Jekyll

SaveURI has a new home!

Persisting/restoring ssh-agent across screen/tmux sessions

'gitweb' setup without root access

Vonage Usage: Python Script

Readability for Chrome: Save to Instapaper

Indian Almanac Bookmarklet

Texnic Center and Adobe Reader X

gContactSync bug

Mapping Win key in Fedora (14)

SaveURI Updated for Firefox 4

while(*a++ == *b++)

Efficient Substr implementation

Binary Search Tree

With Great Power Comes Great Responsibility

JS e-mail Validator

Interesting recursion problem

Stackoverflow Teacher Badge

Metaprogramming is not magic

What I read, am reading and want to read

Why hitting 'reload' speeds up page rendering

Deleting files

HN Submit button

GMail: Automatic Message Translation

Redirecting blogger traffic

Default runlevel on Ubuntu

.bash_profile in ubuntu

Ubuntu sshd

ld terminated with signal 9

Hello WordPress! My new home online!

CVS, ViewVC integration with Google Prettify

NS2 nam error

Google default language

My Reading List

Creating DLLs with MinGW

Global C++ Exception Handler

C/C++ resources online

Wrong Characters being Displayed

ThinkPad T60 TouchPad Scroll in Office 2007

VirusRemoval.vbs Windows Script Host

Install RPMs on Ubuntu

yum ntfs-3g

Adobe Reader Commenting Not Allowed

WIndows Script Host: Unable to open file

TeXnicCenter and Adobe Reader 8.0

Why is switch case better than if else if?

MinGW GProf with Eclipse 3.3 (Europa )

ब्लोग्गीं, और हिंदी मे!

Routing and Remote Access Service Fails!

Now, thats a Palindrome...

Subclipse Proxy Configuration

Testing the RAM for defects on Windows

Sorting Algorithms : A visual treatment

Eclipse Update behind a proxy

Installation of Sun Studio 10 on Sun Solaris Machine

Windows XP Pro: Network access: logon failure

Windows : Autorun is Disabled?

VMWare : SSH access to RH9 from Windows using PuTTY

VMWare : Sharing Files by Connecting to Windows from Linux

VMWare : Internet / FTP / Telnet Access to Linux Guest from Windows Host

VMWare : Internet access from Guest VM (RedHat 9)

while(a++ == b++)