title: Read text file block by block
body: <p>I have text file which contain 200000 rows. I want to read first 50000 rows and then process it and then read second part say 50001 to 100000 etc. When I read second block I don't write to loop on first 1 to 50000. I want that reader pointer directly goes to row number 50001 and start reading.</p>
  
  <p>How it can be possible? Which reader is used for that? </p>