This guy is amazing, I understand him better as I grow up.

We aspire to be like you, but Steve Jobs will always be known as “The crazy one” and “The insanely awesome” visionary!

Your job is done, sleep well :)

And……a small gift for you: StayHungryStayFoolish.me

protected int next(int bits)

Implementation of Random.java via Google code:

1
2
3
4
5
6
7
8
9

    protected int next(int bits) {
        long oldseed, nextseed;
        AtomicLong seed = this.seed;
        do {
            oldseed = seed.get();
            nextseed = (oldseed * multiplier + addend) & mask;
        } while (!seed.compareAndSet(oldseed, nextseed));
        return (int)(nextseed >>> (48 - bits));
    }

The general contract of next is that it returns an int value and if the argument bits is between 1 and 32 (inclusive), then that many low-order bits of the returned value will be (approximately) independently chosen bit values, each of which is (approximately) equally likely to be 0 or 1. The method next is implemented by class Random by atomically updating the seed to

(seed * 0x5DEECE66DL + 0xBL) & ((1L << 48) - 1)

and returning

(int)(seed >>> (48 - bits))

This is a linear congruential pseudorandom number generator, as defined by D. H. Lehmer and described by Donald E. Knuth in The Art of Computer Programming, Volume 3: Seminumerical Algorithms, section 3.2.1.

Interesting!

EDIT: Something even more interesting: Why this code is giving strange result? So Random?

Link to JavaDocs for Random.

Stuff I am using are:

1. ECB – emacs code browser
2. emacs-for-python which includes all the goodies you need for python development!
3. Solarized dark theme, whose emacs port is here.

My fav feature? It’s M-x artist-mode , see a screencast here

(HOW-TO: Use mouse middle button to get options, COMMAND+click on a mac. Exit using M-x artist-mode-off)

If you are using Aquamacs, I recommend you not to use ~/.emacs but directly edit the file which it loads, its located here: ~/Library/Preferences/Aquamacs Emacs/Preferences.el

The ultimate emacs course – An awesome 2hr video lecture for emacs!

Why? Because if you want to customize a desktop at home, there is nothing like buying cheap parts from eBay!

And our app was judged 2nd! The first prize went to an app built with some awesome javascript + eBay API hackery.

Anyway, some highlights:

1. We were using python for the first time. Yes. This was the first time we were using python and django.
2. eBay API were very new to us.
3. We had 14hrs to build a working prototype. It was fun! Photographs of the event on Flickr
4. Something good came out of the hackathon, we are building a python wrapper for eBay API, called python-ebay. It’s an excuse to work more on python and help the eBay at the same time :D

The freebies we got were awesome: Raffles every hour for iPod, Apple TVs, gaming keyboards etc (alas, I had an unlucky number :( ), Snuggies for all of us, 24hr supply of RedBull, eBay developers support through out the Hackathon, more eBay Developer Program swag like T-Shirts and stickers!

Now, coming to the review, how was my experience? Well, it was mixed. eBay API documentation is vast and at times, it’s an information overload.

For example, look at this FindProducts API call reference vs. Google’s custom search API call reference.

I understand, it’s like comparing apples to oranges, but keeping aside the actual functional perspective of the API, it’s not intuitive enough.

An interesting read: What Developers Say About API Documentation

I am sure eBay Developer Program is working really hard to constantly improve it, keeping in mind eBay API is one of the oldest API on the internet. And as of now, we are working on python-ebay which hopefully should be complete by end of this month.

A screenshot of our hack:

Where is it?
Yeah right! It’s a secret!

Also, Node.js is one of the new event driven framework, which is freaking fast! A very good guide to understanding what is Node.js and Event driven programming in it self is very well documented here:

1. Node.js, Doctor’s Offices and Fast Food Restaurants – Understanding Event-driven Programming

2. A Programmer’s Tutorial on Event-Driven Programming, Asynchronous Input/Output, and the Bamboo DHT

Anyway, time for some results!!

Update: You can view the most recent results here

1. What text editor do you use?

Others:

Kod BBEdit Sublime Text 2 eclipse Sublime Text sublime text redcar AkelPad BBEdi tNotepad2 EditPlus sublime text nano Redcar Sublime Text TextWrangler Sublime Text Scite Komodo EditPhpED sublimetext Sublime Editor 2 nano

2. What is your Favorite IDE?

3. What programming language(s) do you use?

PS: People may select more than one checkbox, so percentages may add up to more than 100%. Also, I committed a monumental mistake of not including PHP in the list. So, the Google excel sheet I have shared is a formatted one, which also includes PHP in the charting. The original excel sheet can be found here.

XKCD Image credit: carlos.bueno.org

What is Vyuudha?
Vyuudha – A clean room implementation of a distributed storage middleware for education and research.

So, how do you fix this problem? You create multiple accounts on the Linux EC2 instance and generate keys for every individual accounts, here is how you do it:

Step 0. Login by default user, “ec2-user”:

1

static-9:ec2_thelostlogbook utkarsh$ ssh -i my_key.pem ec2-user@111.111.11.111

Step 1. Create a new user, we will call our new user “john”:

1

[ec2-user@ip-11-111-111-111 ~]$ sudo adduser john

Set password for “john” by:

1
2

[ec2-user@ip-11-111-111-111 ~]$ sudo su
[root@ip-11-111-111-111 ec2-user]$ passwd john

Add “john” to sudoer’s list by:

1

[root@ip-11-111-111-111 ec2-user]$ visudo

and add this to the last line:

1

john   ALL = (ALL)    ALL

Alright! We have our new user created, now you need to generate the key file which will be needed to login, like we have my_key.pem in Step 0.

Now, exit and go back to ec2-user, out of root.

Step 2. Creating the public and private keys:

1

[ec2-user@ip-11-111-111-111 ~]$ su john

Enter the password you created for “john” in Step 1.

1
2
3
4
5
6
7

[john@ip-11-111-111-111 ec2-user]$ cd /home/john/
[john@ip-11-111-111-111 ~]$ ssh-keygen -b 1024 -f john -t dsa
[john@ip-11-111-111-111 ~]$ mkdir .ssh
[john@ip-11-111-111-111 ~]$ chmod 700 .ssh
[john@ip-11-111-111-111 ~]$ cat john.pub > .ssh/authorized_keys
[john@ip-11-111-111-111 ~]$ chmod 600 .ssh/authorized_keys
[john@ip-11-111-111-111 ~]$ sudo chown john:ec2-user .ssh

In the above step, john is the user we created and ec2-user is the default user group.

1

[john@ip-11-111-111-111 ~]$ sudo chown john:ec2-user .ssh/authorized_keys

Step 3. Now you just need to download the key called “john”

I use scp to download/upload files from EC2, here is how you can do it:

You will still need to copy the file using ec2-user, since you only have the key for that user name. So, you will need to move the key to ec2-user folder and chmod it to 777.

1
2

[john@ip-11-111-111-111 ~]$ sudo cp john /home/ec2-user/
[john@ip-11-111-111-111 ~]$ sudo chmod 777 /home/ec2-user/john

Now come to local machine’s terminal, where you have my_key.pem file and do this:

1

static-9:ec2_thelostlogbook utkarsh$ scp -i my_key.pem ec2-user@111.111.11.111:/home/ec2-user/john john

The above command will copy the key “john” to the present working directory on your local machine. Once you have copied the key to your local machine, you should delete “/home/ec2-user/john”, since it’s a private key.

Now, one your local machine chmod john to 600.

1

static-9:ec2_thelostlogbook utkarsh$ chmod 600 john

Step 4. Time to test your key:

1

static-9:ec2_thelostlogbook utkarsh$ ssh -i john john@111.111.11.111

So, in this manner, you can setup multiple users to use one EC2 instance!!

PS: Please post your comments if you find any error.