Ubuntu tips: Add a PPA and update only that one

If you use ubuntu, you most probably have added some ppa-s in your system.
The problem is you have to update all the software sources after adding a ppa by `apt-get update` which is time consuming if you have a lot of software sources.

Y PPA Manager helps to cut down the process. You can only update that ppa easily with Y PPA Manager.

To show you how easy it is you need to execute command



sudo update-ppa ppa:videolan/stable-daily

This will add (if you haven’t already added the ppa) and update the ppa for you.

    To install Y PPA Manager:
sudo add-apt-repository ppa:webupd8team/y-ppa-manager #for the last time
sudo apt-get update #for the last time
sudo apt-get install y-ppa-manager

Android Preference: Show current value in summary

When creating android preference view, I found that the default preference like EditTextPreference does not show the current value as summary (and no way to make them do it). So I made the following class to help:

import android.content.Context;
import android.util.AttributeSet;

public class EditTextPreference extends android.preference.EditTextPreference {

	public EditTextPreference(Context context, AttributeSet attrs) {
		super(context, attrs);
	protected void onDialogClosed(boolean positiveResult) {

	public CharSequence getSummary() {
		return this.getText();

Netbeans tip: Show Files starting with dot (.) [files like .gitignore / .hidden ] in NB Projects

By default Netbeans hides files starting with a dot (.) except the htaccess file.
You can change this behavior by going to
Tools > Options > Miscellaneous > Files
Here you will see “Ignored Files Pattern:” under “Files Ignored by the IDE”
I have changed the pattern to


and now I can see .gitignore, .hidden, etc. files in my projects.


PS: Thanks to Josh Pratt‘s post

Upload to Amazon S3 server directly from browser in chunk and resumable way

UPDATE: This works for AWS sdk version 2.4.0. AWS sdk version 2.4.1 throws body missing exception.

I have written some javascript and php code to make big local files to be uploaded in Amazon S3 server directly, in chunk of 5 MB (amazon web service says that the chunk size should be at least 5MB), so the upload is resumable and recover easily from upload or network error.

To make this work we need our browsers to be able to read local files and send the data to cross-domain server with XMLHttpRequest2. Most mainstream browsers’ recent versions support these operations (Firefox, Chrome, Opera, IE, etc. and some mobile browsers also)

So what do we need? We also need a signing server which will sign the request we will send to the S3 server from browser (Why signing needed? Because we should not allow anybody to upload or manipulate our S3 bucket, shall we?). In my demonstration I used php backend server, but any backend can be used.

If you need a demonstration for inspiration or a starting point for your project, you can look at these source codes here – https://github.com/ienzam/s3-multipart-upload-browser

Please put your valuable comments ans suggestions.

Thank you all for reading.

AWS S3, PHP & Javascript – Get it working

UPDATE: This works for AWS sdk version 2.4.0. AWS sdk version 2.4.1 throws body missing exception.

Let me explain what I was trying to do. I was trying to call amazon web services from javascript directly, but as I can’t (must not) embed aws secret key to javascript I have to use some kind of server to sign my requests for me. As I was working on php, I am trying to use aws-sdk-php to sign my requests. After a lot of digging on the sdk code here is the rough hack code I have came up with (you need to set cors permission on your bucket to access from javascipt)

require 'vendor/autoload.php';

use Aws\Common\Enum\DateFormat;
use Aws\S3\S3Client;
use Guzzle\Common\Event;

$client = S3Client::factory(array(
'key' => AWS_KEY,
'secret' => AWS_SECRET

// for all available commands, go to
// http://docs.aws.amazon.com/aws-sdk-php-2/guide/latest/service-s3.html
$command = $client->getCommand('GetBucketAcl', array(
'Bucket' => BUCKET_NAME

$request = $command->prepare();
$request->setHeader('x-amz-date', gmdate(DateFormat::RFC2822));

// searching for these event dispatchers wasted a great deal of my time 😡
$client->getEventDispatcher()->dispatch('command.before_send', new Event(array(
'command' => $command,

$client->getEventDispatcher()->dispatch('request.before_send', new Event(array(
'request' => $request
<p>Open the browser console and network monitor to see the outputs</p>
<button onclick=&quot;doXMLHttpRequest()&quot;>XMLHttpRequest</button>
<button onclick=&quot;doJQueryRequest()&quot;>JQuery Request</button>
<script src=&quot;jquery-1.9.1.min.js&quot;></script>
var url = &quot;<?php echo($request->getUrl()) ?>&quot;;
var authHeader = &quot;<?php echo($request->getHeader('Authorization')) ?>&quot;;
var dateHeader = &quot;<?php echo($request->getHeader('x-amz-date')) ?>&quot;;
var methodType = &quot;<?php echo($request->getMethod()) ?>&quot;;


function doXMLHttpRequest() {
var request = new XMLHttpRequest();
request.open(methodType, url, true);
request.onreadystatechange = function() {
if (request.readyState === 4) {
console.log(&quot;Request complete from XMLHttpRequest, request object below&quot;);
request.setRequestHeader(&quot;x-amz-date&quot;, dateHeader);
request.setRequestHeader(&quot;Authorization&quot;, authHeader);

function doJQueryRequest() {
url: url,
headers: {
Authorization: authHeader,
&quot;x-amz-date&quot;: dateHeader
type: methodType
}).done(function(data) {
console.log(&quot;Request complete from JQuery, response data below&quot;);

Yes I know I have written very short description. But check out the code, that’s what matters, right? ( I am lazy 😛 )

How to Solve Netbeans Error “No tracked remote branch specified for local branch-name”

Short answer:
As of Git 1.7.0:
git branch --set-upstream foo upstream/foo

Long Answer:
Netbeans 7.3 introduce three new feature for git remote

  • Fetch from Upstream
  • Pull From Upstream
  • Push to Upstream

But whenever I tried to use this commands, it gave me the error
“No tracked remote branch specified for local branch-name”

After digging around for a while, I found the solution.
git branch --set-upstream branch-name remote-name/remote-branch-name

Thanks to this so answer: http://stackoverflow.com/a/2286030/472538

Now set up keyboard shortcuts for the commands and also for commit and increase your productivity 😀

Facebook Extra Emoticons (Emoji)

Facebook Emoji

Facebook has given some exclusive emoticons to it’s mobile messenger (which are actully emoji). Now you can use it on desktop too. Just choose your emoticon from below and paste it in your messenger (warning: many will not work in facebook web page if you use messenger like Pidgin it will work) 😀











Will post with facebook image of the emoticons later.


বাংলাদেশের উপজেলাগুলোর স্থানাঙ্ক (Coordinates of Upzilla’s of Bangladesh)

কিছুদিন আগে ঢাকায় হয়ে গেল সেনিটেশন হ্যাকাথন বাংলাদেশ। ওখানে একটা প্রজেক্টে সব ইউনিয়ন পরিষদের স্থানাঙ্ক লাগছিল, এজন্য খুঁজলাম কোথায় পাওয়া যায়। দেখলাম ভালো কোন সোর্স নাই, তবে উইকিপিডিয়ায় দেখলাম আছে। কিন্তু কালেক্ট করার কোন সহজ ব্যবস্থা দেখলাম না। তো অনেক কষ্টে সব কালেক্ট করলাম, কারো যদি ভবিষ্যতে লাগলে তাই এখানে দিয়ে দিলাম

CSV – https://dl.dropbox.com/u/5548100/Upzilla/Upzilla%20Coordinates.csv
JS – https://dl.dropbox.com/u/5548100/Upzilla/Upzilla%20Coordinates.js

গুগল ম্যাপে স্থানাঙ্কগুলোর ডিমো দেখতে চাইলে এই লিঙ্কে – https://dl.dropbox.com/u/5548100/Upzilla/show_map.htm

পুনশ্চঃ যেহেতু Wikipedia-র তথ্য CCSAL এ, তাই উপরের সব একই লাইসেন্সে দেওয়া হল।

(পুনশ্চঃ তবে কেউ ব্যবহার করলে কমেন্ট দিলে ভালো লাগবে 😛 )

Google Campus Recruitment Test

So for the first time Google conducted campus recruitment tests in Bangladesh. The test was conducted by Google India for jobs in Google USA.

This year the tests took place on Bangladesh University of Engineering & University (BUET), Dhaka University and North South University. The recently graduated batch and going to be graduated batch of the universities took part in the tests. The tests are indipendent, at BUET the test were on October 9, 2012 (http://www.buet.ac.bd/cse/calevents/calevents.php?eventsid=69). I am currently studying at BUET and took the test there.

The test took at exam hall, ECE building, BUET. First the delagates presented a presentation about Google, answered our questions. The presentation was great, we felt excited to know about Google and workspace and other fun and important parts about Google.

Then started the written exam. We are asked to bring pencil so that we can easily correct our codes as we have to write codes. The written test had two parts.

In first part, the questions are about algorithm complexity, algorithm categorization and network.

In second part, there are two coding problems. One is about bracket matching and another is about queue stack implementation. The delegates clearly instructed us to write code in popular languages like C++ / Java, not any pseudocode. They also instructed us to write correct, readble, clean code, and if possible generic code (like template code). By correct they did not mean correct syntax, missing some semicolon is not the problem, but correcting the format and other things.

I am not a good writer so forgive about the low quality 😛

টপকোডারে প্র্যাকটিস করা

টপকোডার সবচেয়ে পপুলার এবং ভালো অনলাইন জাজ গুলোর মধ্যে অন্যতম। তবে এখানে কনটেস্ট করার ধরনটা একটু ভিন্ন ধরনের। এখানে কিভাবে প্র্যাকটিস করতে হবে তার জন্য smilitude ভাইয়ের একটি সুন্দর টিউটোরিয়াল আছে, টিউটিরিয়ালটি pdf ফরম্যাটে। লিঙ্ক – https://sites.google.com/site/smilitude/topcoder.pdf

Click to access topcoder.pdf

ধন্যবাদ 🙂