A simple No-SQL key-value db using self-modifying ruby script: An interesting application of Ruby's Reflection API

I am basically a java developer and I recently started learning ruby and was amazed at the ease in which you can develop in it and elegance of the language. The easiest way to learn any programming language is to develop simple applications in it that use various features of language. So when going through the various features I came across Reflection and Metaprogramming in Ruby. A very powerful feature in ruby. It amazing how the eval function allows one to write and execute ruby code dynamically. So while thinking of an application using this feature I came up with the following application.
It is a simple No-SQL key-value db that stores data in hash in ruby. The first line declares a hash. Then the following part of script reads its own code and uses eval function to execute it declare the hash. Then depending upon the function called GET/SET it either retrieves the value associated with the key or sets a new key/value in hash. Then it simply stores the new hash in the source code.
Here is the source code for the ruby script:

hash={"1"=>"Narendra", "2"=>"Mangesh", "3"=>"Viru", "4"=>"Virendra", "5"=>"Genh"}
z=[]
err_msg="ruby #{__FILE__} <GET/SET> <key_to_search/key_to_set> <not_required/value_to_set>"
if ARGV.length<2 && (ARGV[0]!="GET" || ARGV[0]!="SET")
  puts err_msg
  exit
end
if ARGV[0]=="SET" && ARGV.length!=3
  puts err_msg
  exit
end
File.open(__FILE__,'r'){|f| f.each_line {|l| z<<l}}
c=eval(z[0])
if ARGV[0]=="GET"
  puts c[ARGV[1]] if c.include?(ARGV[1])
elsif ARGV[0]=="SET"
  c[ARGV[1]]=ARGV[2]
  z[0]="hash="+c.inspect+"\n"
  File.open(__FILE__,'w'){|f| z.each{|x| f<<x}}
end

Hacking the Little Alchemy game with only Chrome in less than an hour

Today my friend introduced me to this cute little but addictive game named Little Alchemy.
So playing around with it for few minutes and looking at the time it took to find new elements I wondered how much time it would take to find all. Not having the patience to play whole game to determine all elements I thought why not do it the hacker style. So popped open the Chrome Web Inspector and looked around in the network tab to see what all data is sent by littlealchemy web page. I noticed it stores all data in application cache and retrieves from there. Looking around the js files for something interesting I struck gold when I found the logic in alchemy.js file. It seemed to make ajax call to 2 files /base/names.json and /base/base.json. Then I looked into these files and found that the mapping of all the elements was stored in base.json in array forms and all the names of elements were stored in names.json. After finding this it was a piece of cake to hack together a javascript code to display the combinations for all elements. So then I opened the javascript console and put together this piece of code to print the combinations for all elements and dumped it to a html file. You can check the output here.

And here is the piece of javascript code

var base,names,i,j;
$.ajax({
          type: "GET",
          url: "http://littlealchemy.com/base/base.json",
          }).done(function( data ) {
          base=data;
});
$.ajax({
          type: "GET",
          url: "http://littlealchemy.com/base/names.json",
          }).done(function( data ) {
          names=data;
});
for(i=4;i<base.base.length;i++){
   for(j=0;j<base.base[i].length;j++){
      if(names.lang[Number(base.base[i][j][0])]==undefined){
         console.log(names.lang[i]+ " doesn't have any combination");
         continue;
      }
      console.log(names.lang[Number(base.base[i][j][0])]+" + "+names.lang[Number(base.base[i][j][1])]+" => "+names.lang[i]);
   }
}