title: Load file in Pig and Transform it to one row with separator
body: <p>i need your help please to output my file loaded in Pig which contains data like this : </p>
  
  <pre><code>AAAA,message1
  BBBB,message2
  CCCC,message3
  DDDD,message4
  </code></pre>
  
  <p>and what i need to do is to get an output like this</p>
  
  <pre><code>AAAA,message1,BBBB,message2,CCCC,message3,DDDD,message4
  </code></pre>
  
  <p>this output i will use it in other pig udf after..</p>
  
  <p>thank you for your help </p>