Geek Languages

package wordcount;
       
import java.io.IOException;
import java.util.Iterator;
import java.util.StringTokenizer;

import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapred.FileInputFormat;
import org.apache.hadoop.mapred.FileOutputFormat;
import org.apache.hadoop.mapred.JobClient;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.MapReduceBase;
import org.apache.hadoop.mapred.Mapper;
import org.apache.hadoop.mapred.OutputCollector;
import org.apache.hadoop.mapred.Reducer;
import org.apache.hadoop.mapred.Reporter;
import org.apache.hadoop.mapred.TextInputFormat;
import org.apache.hadoop.mapred.TextOutputFormat;

public class WordCount
{
  public static class Map extends MapReduceBase implements
            Mapper<LongWritable, Text, Text, IntWritable>
      {

 public void map(LongWritable key, Text value, OutputCollector<Text,  IntWritable> output, Reporter reporter)
            throws IOException
        {
            String line = value.toString();
            StringTokenizer tokenizer = new StringTokenizer(line);

            while (tokenizer.hasMoreTokens())
           { 
                value.set(tokenizer.nextToken());
                output.collect(value, new IntWritable(1));
           }

      }
    }

    public static class Reduce extends MapReduceBase implements
            Reducer<Text, IntWritable, Text, IntWritable>
      {
        public void reduce(Text key, Iterator<IntWritable> values,
                OutputCollector<Text, IntWritable> output, Reporter reporter)
                throws IOException
        {
               int sum = 0;
               while (values.hasNext())
           {
               sum += values.next().get();
            }

            output.collect(key, new IntWritable(sum));
       }
    }

    public static void main(String[] args) throws Exception

 {     JobConf conf = new JobConf(WordCount.class);                                                conf.setJobName("wordcount");

        conf.setOutputKeyClass(Text.class);
        conf.setOutputValueClass(IntWritable.class);

        conf.setMapperClass(Map.class);
        conf.setReducerClass(Reduce.class);

        conf.setInputFormat(TextInputFormat.class);
          conf.setOutputFormat(TextOutputFormat.class);

        FileInputFormat.setInputPaths(conf, new Path(args[0]));
        FileOutputFormat.setOutputPath(conf, new Path(args[1]));

       JobClient.runJob(conf); 

    }
}

                        <<<<<<COMMANDS>>>>>>>>>




hadoop fs ls:

The hadoop ls command is used to list out the directories and files. An example is shown below:


$./hadoop fs -ls input/
Found 1 items
drwxr-xr-x   - hadoop hadoop  0 2013-09-10 09:47 /input/abc.txt

-------------------------------------
hadoop fs lsr:

The hadoop lsr command recursively displays the directories, sub directories and files in the specified directory. The usage example is shown below:

$./hadoop fs -lsr /user/hadoop/dir
Found 2 items
drwxr-xr-x   - hadoop hadoop  0 2013-09-10 09:47 /user/hadoop/dir/products
-rw-r--r--   2 hadoop hadoop    1971684 2013-09-10 09:47 /user/hadoop/dir/products/products.dat

------------------------------------
hadoop fs cat:

Hadoop cat command is used to print the contents of the file on the terminal. The usage example of hadoop cat command is shown below:
EX:
hadoop fs -cat input/abc.txt

-------------------------------
hadoop fs chmod:

The hadoop chmod command is used to change the permissions of files. The usage is shown below:
SYNTAX:
hadoop fs -chmod  <octal mode> <file or directory name>
EX:
$./hadoop fs -chmod 700 input/abc.txt

--------------------------------------------
hadoop fs chown:

The hadoop chown command is used to change the ownership of files. The usage is shown below:
SYNTAX
hadoop fs -chown <NewOwnerName> <file or directory name>
EX:
$./hadoop fs -chown hadoop input/abc.txt
---------------------------------------
hadoop fs mkdir:

The hadoop mkdir command is for creating directories in the hdfs. You can use the -p option for creating parent directories. This is similar to the unix mkdir command. The usage example is shown below:


$./hadoop fs -mkdir -p input/

The above command creates the input directory in /user/ratul directory.
-------------------------------
hadoop fs copyFromLocal:

The hadoop copyFromLocal command is used to copy a file from the local file system to the hadoop hdfs. The syntax and usage example are shown below:

Syntax:
hadoop fs -copyFromLocal <source> <destination>

Example:

Check the data in local file
> cat sales.txt
2000,iphone
2001, htc

Now copy this file to hdfs

$./hadoop fs -copyFromLocal /home/ratul/sales.txt input/

View the contents of the hdfs file.

$./hadoop fs -cat input/sales.txt
2000,iphone
2001, htc
-----------------------------------
hadoop fs copyToLocal:

The hadoop copyToLocal command is used to copy a file from the hdfs to the local file system. The syntax and usage example is shown below:
SYNTAX
hadoop fs -copyToLocal <source> <destination>
EX:
$./hadoop fs -copyToLocal input/sales.txt /home/ratul/

---------------------------
hadoop fs cp:

The hadoop cp command is for copying the source into the target. The cp command can also be used to copy multiple files into the target. In this case the target should be a directory. The syntax is shown below:
SYNTAX
>hadoop fs -cp <source> <destination>
EX:
$./hadoop fs -cp input/sales.txt new/

----------------------------
hadoop fs put:

Hadoop put command is used to copy multiple sources to the destination system. The syntax for the put command are shown below:

Syntax1: copy single file to hdfs

>./hadoop fs -put home/ratul/abc.txt input/

Syntax2: copy multiple files to hdfs

>./hadoop fs -put home/ratul/abc.txt home/ratul/qwerty.txt /new_folder

---------------------------------
hadoop fs get:

Hadoop get command copies the files from hdfs to the local file system. The syntax of the get command is shown below:
SYNTAX:
hadoop fs -get <source_from_hdfs> <destination_to_local>
EX:
$./hadoop fs -get input/abc.txt /home/ratul/
-------------------------------------
hadoop fs moveFromLocal:

The hadoop moveFromLocal command moves a file from local file system to the hdfs directory. It removes the original source file. The usage example is shown below:
SYNTAX:
hadoop fs -moveFromLocal <source_from_local> <destination_to_hdfs>
EX:
$./hadoop fs -moveFromLocal /home/ratul/abc.txt input/

-------------------------------
hadoop fs mv:

It moves the files from source hdfs to destination hdfs. Hadoop mv command can also be used to move multiple source files into the target directory. The syntax is shown below:
SYNTAX:
hadoop fs -mv <SrcFile> <destinationFile>
EX:
$./hadoop fs -mv input/abc.txt input/a/


----------------------
hadoop fs du:

The du command displays aggregate length of files contained in the directory or the length of a file in case its just a file. The syntax and usage is shown below:

$./hadoop fs -du abc.txt
------------------------------
hadoop fs rm:

Removes the specified list of files and empty directories. An example is shown below:

$./hadoop fs -rm input/file.txt
--------------------------------
hadoop fs -rmr:

Recursively deletes the files and sub directories. The usage of rmr is shown below:
$./hadoop fs -rmr input/folder/
-------------------------------------
hadoop fs setrep:

Hadoop setrep is used to change the replication factor of a file.

Example:
$./hadoop fs -setrep - 3 /input/abc.txt


---------------------------------
hadoop fs stat:

Hadoop stat returns the stats information on a path. The syntax of stat is shown below:
EX:
$./hadoop fs -stat /input/abc.txt
2013-09-24 07:53:04
----------------------------
hadoop fs tail:

Hadoop tail command prints the last 10 lines of the file. 
$./hafoop fs -tail /user/hadoop/abc.txt

12345 abc
2456 xyz
---------------------
hadoop fs text:

The hadoop text command displays the source file in text format. The syntax is shown below:
SYNTAX:
hadoop fs -text <src>
EX:
$./hadoop fs -text input/abc.txt

----------------------------------------
hadoop fs touchz:

The hadoop touchz command creates a zero byte file. This is similar to the touch command in unix. The syntax is shown below:
SYNTAX:
$./hadoop fs -touchz /input/aaa.txt

class Person < ApplicationRecord
  validates :name, presence: true
end

 OR

class Person < ApplicationRecord
  validates :name, :login, :email, presence: true
end

class Person < ApplicationRecord
  validates :terms_of_service, acceptance: true
end

class Person < ApplicationRecord
  validates :email, confirmation: true
end

class Product < ApplicationRecord
  validates :legacy_code, format: { with: /\A[a-zA-Z]+\z/,
    message: "only allows letters" }
OR a-z,A-Z,0-9
end

class Person < ApplicationRecord
  validates :name, length: { minimum: 2 }
  validates :bio, length: { maximum: 500 }
  validates :password, length: { in: 6..20 }
  validates :registration_number, length: { is: 6 }
end

class Player < ApplicationRecord
  validates :points, numericality: true
end

class Account < ApplicationRecord
  validates :email, uniqueness: true
end

TAGS:

ERB tags                   <%    %>
print ERB tags          <%=  %>
print ERB comment  <%# %>
if block                      <% if %>...<% end %>
if / else                       <% if %>...<% else %>...<% end %>
else tag     else           <% else %>
elsif tag     elsif          <% elsif %>
end block     end        <% end %>
link_to helper             <%= link_to ..., ... %>
form_for helper     form      <%= form_for(@) do %>

Helpers:

   Form Component     Output Code Snippet

   f.submit                       <%= f.submit "Submit"  %>
   f.password_field          <%= f.password_field :attribute %>
   f.text_area                   <%= f.text_area :attribute %>
   f.check_box                 <%= f.check_box :attribute %>
   f.label                          <%= f.label :attribute, "Attribute" %>
   f.text_field                   <%= f.text_field :attribute %>
   f.file_field                    <%= f.file_field :attribute %>
   f.hidden_field              <%= f.hidden_field :attribute %>

<html>
       
<body>
<!----heading-->
<h1> GEEK</h1>
<h1>Geek Languages</h1>
<hr />
<h2>Geek Languages</h2>
<hr />
<h3>Geek Languages</h3>
<h4>Geek Languages</h4>
<h5>This is a Heading 5</h5>
<h6>Geek Languages</h6>
<!---paragraph-->
<p>Geek Languages</p>

<p>
My Bonnie lies over the ocean.
My Bonnie lies over the sea.
My Bonnie lies over the ocean.
Oh, bring back my Bonnie to me.
</p>

<!---tags-->
<p><b>This text is bold</b></p>
<p><strong>This text is strong</strong></p>
<p><big>This text is big</big></p>
<p><em>This text is emphasized</em></p> <br />
<p><i>This text is italic</i></p><br />
<p><small>This text is small</small></p>
<p>This is_subscript and ^superscript
</p>
<p>
a dozen is
<del>twenty</del>
<ins>twelve</ins>
pieces
</p>

<!--pre fromateed text--->
<pre>
This is
preformatted text.
It preserves
both spaces
and line breaks and shows the text in a monospace font.
</pre>

<!-- anchor tag--->
<a href="http://www.geeklanguages.blogspot.com">This is a link to my Web site.</a>

<!-- IMAGE TAG-->
<img src="aa.png" width="104" height="142" /> <br/>
<!-- ABBREVATION-->
<abbr title="United Nations">UN</abbr>
<br />
<acronym title="World Wide Web">WWW</acronym>


<!---table-->
<h4>A background image:</h4>
<table border= "3" background="aa.png">
<tr>
<td bgcolor = blue>First</td>
<td>Row</td>
</tr>
<tr>
<td>Second</td>
<td>Row</td>
</tr>
<tr>
</table>

<!---table with spans-->

<h4>Cell that spans two columns:</h4>
<table border="1">
<tr>
<th>Name</th>
<th colspan="2">Telephone</th>
</tr>
<tr>
<td>Bill Gates</td>
<td>555 77 854</td>
<td>555 77 855</td>
</tr>
</table>

<!---table with cell padding-->
<h4>With cellpadding:</h4>
<table border="1" cellpadding="10">
<tr>
<td>First</td>
<td>Row</td>
</tr>
<tr>
<td>Second</td>
<td>Row</td>
</tr>
</table>

<div>
<table border = "2">
<th align="left">Money spent on....</th>
<th align="right">January</th>
<th align="right">February</th>
</tr>
</table>
</div>
<!--text color-->
<p style="color:grey" width = "150">
Color set by using color name
</p>



<!--Ordered (Numbered) List-->
<ol>
<li>First item</li>
<li>Next item</li>
</ol>

<!---  Definition List -->
<dl>
<dt>First term</dt>
<dd>Definition</dd>
<dt>Next term</dt>
<dd>Definition</dd>
</dl>


<!--Unordered list--->
<h4>A nested List:</h4>
<ul>
<li>Coffee</li>
  <li>Tea
   <ul>
<li>Black tea</li>
<li>Green tea
      <ul>
<li>China</li>
<li>Africa</li>
      </ul>
   </li>
</ul>
</li>
<li>Milk</li>
</ul>
</body>


</html>

<!---USE OF FRAMES--->
<html>
<frameset rows="50%,50%">
<frame src="frame_a.htm">
<frameset cols="25%,75%">
<frame src="frame_b.htm">
<frame src="frame_c.htm">
</frameset>
</frameset>
</html>

Ruby was created by Yukihiro Matsumoto, or "Matz", in Japan in the mid 1990's. It was designed for programmer productivity with the idea that programming should be fun for programmers. It emphasizes the necessity for software to be understood by humans first and computers second.
Ruby continues to gain popularity for its use in web application development. The Ruby on Rails framework, built with the Ruby language by David Heinemeier Hansson, introduced many people to the joys of programming in Ruby. Ruby has a vibrant community that is supportive for beginners and enthusiastic about producing high-quality code.

Features of Ruby

• Ruby is an open-source and is freely available on the Web.
• Ruby is a general-purpose, interpreted programming language.
• Ruby is a true object-oriented programming language.
• Ruby is a server-side scripting language similar to Python and PERL.
• Ruby can be embedded into Hypertext Markup Language (HTML).
• Ruby has a clean and easy syntax that allows a new developer to learn Ruby very quickly and easily.
• Ruby has similar syntax to that of many programming languages such as C++ and Perl.
• Ruby is very much scalable and big programs written in Ruby are easily maintainable.
• Ruby can be used for developing Internet applications.
• Ruby can be installed in Linux,Windows environments.
• Ruby can easily be connected to Sqlite, MySQL, Oracle.
• Ruby has a rich set of built-in functions, which can be used directly into Ruby scripts.

#class with rescue and raise in ruby program

class Question
attr_accessor  :a1, :a2
def initialize(a1,a2)
@a1=rand(50)
@a2=rand(50)

end
def make_random_substraction
begin
puts 'Random Substraction of two numbers.'

puts "What is '#@a1' - '#@a2' ?"


@a3 = Integer(@a1) - Integer(@a2)
puts "#@a3"

if @a3<0
raise 'exception'
end

rescue
puts "An exception : answer is in negative value."
puts "Lets retry it in other order."
@a3 = Integer(@a2) - Integer(@a1)

puts "Here, answer is : #@a3"
 
end
end
end
obj=Question.new(@a1,@a2)
obj.make_random_substraction