/me on the net! - utilities

On the fly compression of mysqldump

nospam@example.com (Anurag) — Mon, 25 Jun 2012 19:53:19 +0530

mysqldump -uroot -pPASSWORD --opt --all-databases | bzip2 -c > mysql-full-dump.bz2

What's new in Firefox 5!

nospam@example.com (Anurag) — Tue, 28 Jun 2011 18:12:15 +0530

Convert videos for Android (Samsung Galaxy)

nospam@example.com (Anurag) — Tue, 22 Feb 2011 00:21:30 +0530

My Android phone doesn't support DivX/XviD. To play videos on it. I need to convert them to MP4. Taking a note for myself if I need it later.

$ ffmpeg -i input_video.avi -f mp4 -vcodec libx264 -acodec libfaac -s 400x240 -ab 128k output_video.mp4

400x240 is the phone's screen resolution.

[Edit] Good parameters for high quality MPEG4 encoding:

-mbd rd -flags +mv4+aic -trellis 2 -cmp 2 -subcmp 2 -g 300

Mumbai, Delhi, Pune, Ahmedabad - Autorickshaw Taxi fares

nospam@example.com (Anurag) — Thu, 26 Aug 2010 14:09:32 +0530

Rickshaw fares for Mumbai

Two months back Mumbai's autorickshaw and taxi drivers went on a strike, demanding a steep increase in fares. While earlier the fare calculation was simple, after the new fare structure came in place, autorickshaw fare calculations became relatively complex.

I started http://rickfare.com on the day new fares came into effect after seeing the new complicated fare structure. Over time, friends pitched in for their cities and I added New Delhi, Ahmedabad, Pune and Navi Mumbai. Today Rickfare.com is accessed by thousands of commuters over a wide variety of mobile devices including iPhone, BlackBerry, Android, HTC and assorted Nokia handsets.

I'd like to thank Ashish Mehta, Atul Jha, Kartik Mistry and Kamaleshwar for helping out with auto fares of their cities

Extract mp3 audio from a video clip using mencoder

nospam@example.com (Anurag) — Mon, 17 May 2010 13:52:44 +0530

This post is a note for self. I always keep forgetting how to extract mp3 audio file from any video clip.

$ mencoder videofile.avi -of rawaudio -oac mp3lame -ovc copy -o audio-output.mp3

This is an awesome companion to the youtube video downloader - youtube-dl.py

Server sent unexpected return value (502 Bad Gateway) in response to COPY request

nospam@example.com (Anurag) — Wed, 21 Apr 2010 10:46:14 +0530

During the recent server migration, I shifted svn services from http to https. Everything seemed to work fine, except for this error while creating branches.

frodo$ svn cp https://svn.xinh.org/svn/project/UberCool/trunk https://svn.xinh.org/svn/project/UberCool/branches/1.0

svn: Server sent unexpected return value (502 Bad Gateway) in response to COPY request for '/svn/project/!svn/bc/15/UberCool/trunk'

svn: Your commit message was left in a temporary file:

svn:    'svn-commit.tmp'

frodo$

Googling around a bit helped. I'm using HTTPS over Apache + dav_svn module. This issue can be fixed by enabling mod_headers module in Apache and adding the following line at the end of your VirtualHost.

RequestHeader edit Destination ^https http early

MovieAB - A tiny movie mashup

nospam@example.com (Anurag) — Mon, 23 Feb 2009 19:10:16 +0530

Announcing MovieAB -- a mashup of freely available movie data APIs from around the internet. A catalog of over 170000 movie titles, tv series, programs available on DVD, actors and directors is available at the moment, and keeps growing every day.

Try a sample page for the movie Spider-Man 2. Every movie info page displays DVD box-art image, netflix user ratings, genres, a short summary, cast, awards and nominations and movie reviews from NYTimes if its available.

MovieAB came up as an idea to implement Netflix's API, after they decided to open up their vast catalog of movie data to third party developers. This was soon followed up with New York Times' decision to open up their comprehensive movie reviews api to third party developers. I can't thank them enough.

And, what's this AB? Well, I have no idea. This was the smallest domain name available. iMovie, gMovie, LiveMovie are all taken

Many thanks to Kamaleshwar for designing this clean and simplistic logo. More artwork requests from me are coming your way! If you liked the application, have suggestions for improvement, criticisms, bug reports or general feedback - write in to feedback (at) movieab.com.

MovieAB movie summary

Spider-Man 2

Movie info by MovieAB

USD INR exchange rates

nospam@example.com (Anurag) — Mon, 05 Jan 2009 15:48:18 +0530

I keep looking at stuff and try guessing its price in INR. Look around for calculator, check USD exchange rate and punch it in.

#!/usr/bin/env ruby

require 'rubygems'

require 'hpricot'

require 'open-uri'



FPAGE = 'http://finance.yahoo.com/q?s=USDINR=X'

XPATH = '/html/body/div/div[2]/div[4]/div[2]/div/div[2]/table/tr/td/big/b/span/'



amount = (ARGV.length == 1) ? ARGV[0].to_f : 1

amount = 1 if amount == 0



doc = Hpricot(URI.parse( FPAGE ).read)

element = doc.search( XPATH )

exchange_rate = element[0].to_s.to_f

puts "#{amount} USD = #{amount * exchange_rate} INR"

Now i no longer have to. Just running $ usdinr 197.21 gives the amount in INR. Save this file in /usr/bin/usdinr and give execute permissions.

[Update 2009-02-19: Updated the script with new XPath]
[Update 2010-12-08: Updated the script with new Yahoo finance page and XPath]

Tata Indicom wireless data card (Huawei EC321 CDMA card)

nospam@example.com (Anurag) — Wed, 06 Aug 2008 02:03:08 +0530

Tata indicom Vdata card

I've been using Tata Indicom's data card based internet services for the past 2 years or so. and my experience about the internet service quality has been above satisfaction so far. After filling up the application form, and paying 4990 INR upfront for the data card, i got the card delivered at home in 2 days. Pretty fast indeed.

Data card connectivity speed: The Huawei EC321 CDMA card is rated for about 156Kbps. Initially at the place where i used to live, i used to get about 140 Kbps speed without fiddling too much with the antenna and direction. At my current residence too, i manage about the same speeds, which is more than enough for my email and IRC applications

Setup and installation: The data card comes as a PCMCIA device which can be plugged onto the PCMCIA slot of your laptop. Its probably straightforward to install it in Windows. There's a desktop manager application included in the installation CD with puts a dialer-cum-sms inbox checking app shortcut on the desktop. Getting the internet working on linux is even easier. Check how to get the data card running with wvdial here.

Tariff plans: The data card costed me around 4990 INR some 2 years back. It should be cheaper now. The USB pen drive shaped Plug2Surf ones are definitely cheaper. I am under 1GB plan which costs me less than 800 INR per month with taxes included, as i never cross my 1GB limit.

Network coverage and roaming: Its based on Tata Indicom's CDMA network, so internet services work wherever there's tata indicom's mobile phone network. So far, it has worked for me in all the cities i've traveled in india. There are no charges on national roaming if you are using the data card only for internet services.

Verdict?: Its a good gadget to keep along if you are traveling. Internet works just out of the box, without having to ask anyone for network access or proxy authentications. I haven't used data card services from Reliance or Airtel, but i dont really have a reason to switch services as yet. Lately there have been days when the internet is pathetically slow but then it comes back again.

Where to buy?: You can visit their website ichoose.in and place an order. If you are in Mumbai then let me know, i can pass over the contact information of their sales representative and he'll take care of the rest. My email address is anurag (@) gnuer.org

flickr toys

nospam@example.com (Anurag) — Wed, 05 Mar 2008 18:10:18 +0530

Hockeney picture

Looking for a way to generate a jigsaw puzzle from your photos? or a Polaroid style Hockney picture? a picture cube? or a original looking Flickr badge? Head over to Big Huge Labs and make your own nifty Flickr accessories.

naming your hosts

nospam@example.com (Anurag) — Sat, 29 Dec 2007 17:12:27 +0530

Apparently, there's an RFC on Choosing a Name for Your Computer - RFC 1178. Easily, one of the simpler to understand RFCs out there.

migrating mailman

nospam@example.com (Anurag) — Sun, 25 Nov 2007 03:57:00 +0530

1. Introduction
A couple of weeks back we had to migrate a few mailing lists across to a new server. Migration was successful and we had minimum downtime, since no changes were done to the lists.

This HowTo assumes that the new server uses Postfix as an MTA. Using any other MTA is not a problem as long as it can read the Mailman generated aliases file.

Migrating mailman lists is a 3 step process.

2. Preparing New Server.

2.1 Installing Mailman.

/usr/local/mailman

/var/lib/mailman

2.2 Configure Apache and Postfix.

3. Copying Data to New Server.
Copying data involves copying over three directories, which hold list configuration(lists), held messages/bounce stats(data) and list archives(archives).

3.1 lists

lists

# rsync -avz /usr/local/mailman/lists root@new-server:/var/lib/mailman/

Mailman

3.2 data

data

# rsync -avz /usr/local/mailman/data root@new-server:/var/lib/mailman/

3.3 archives

archives

# rsync -avz /usr/local/mailman/archives root@new-server:/var/lib/mailman/

4. Post Migration checks.
After the data is migrated, check for any permission issues. Its possible that the new server is configured to run mailman with the user list or mailman. Change the ownership of the directories copied accordingly.

4.1 Regenerating Aliases

bin

# cd /var/lib/mailman/bin

# ./genaliases

4.2 Hostnames

web_page_url

host_name

# cd /usr/local/mailman/bin

# ./withlist -l -r fix_url  -u new-domain.example.org

4.3 DNS Updates

5. Finalising
Try to send an email to any of the lists's -request alias, with `help' in the subject line. Mailman should immediately respond with a list of available commands.

6. Refrences
Mailman Homepage - http://www.list.org
Mailman Installation Manual -http://list.org/mailman-install/index.html

HTTP Auth with mod_auth_imap

nospam@example.com (Anurag) — Tue, 03 Jul 2007 15:07:00 +0530

HTTP based authentication is the most common and easy-to-setup way of protecting content in apache. But with normal .htaccess/.htpasswd based protection, the problem is, .htpasswd file should be present in the webserver's filesystem, and in most cases those users are not local unix users.

mod_auth_imap attempts to overcome this limitation by allowing apache to authenticate against an IMAP server, local/remote/whatever. Setting up authentication with mod_auth_imap is also straightforward.

Download the mod_auth_imap tarball from http://ben.brillat.net/projects/mod_auth_imap/, and extract the contents.
Make sure apxs is installed (its available in apache2-dev package in debian)
Run # apxs -i -a -c mod_auth_imap.c as root user to build the apache module and install it in apache.
Make sure that mod_auth_imap module is enabled in your apache configuration.

An example .htaccess file will look like this.

#Turn on IMAP Authentication

Auth_IMAP_Enabled on

AuthName "Use IMAP username to login"

AuthType Basic



# Turn off Basic auth. We'll make IMAP as authoritative.

AuthBasicAuthoritative Off



#If you feel like it, restrict the users or allow all valid users:

# Require user foouser

Require valid-user



#Make IMAP Authentication authoritative for this .htaccess file:

Auth_IMAP_Authoritative on

Auth_IMAP_Server imap.example.org

Auth_IMAP_Port 143

Auth_IMAP_Log on

writing cheques made easy

nospam@example.com (Anurag) — Thu, 21 Jun 2007 00:44:25 +0530

If you issue cheques very often, and wonder how to write that weird amount in words, then lisp may come to your rescue.

CL-USER> (format t "~R" 5374538457834758345)

five quintillion three hundred seventy-four quadrillion five hundred thirty-eight trillion four hundred fifty

-seven billion eight hundred thirty-four million seven hundred fifty-eight thousand three hundred forty-five

NIL

CL-USER>

reverser

nospam@example.com (Anurag) — Thu, 05 Apr 2007 10:31:00 +0530

Konqueror

ever wondered how KDE apps look like when they are viewed in reverse?

$ konqueror --reverse