title: Count lines in large files
body: <p>I commonly work with text files of ~20 Gb size and I find myself counting the number of lines in a given file very often.</p>
  
  <p>The way I do it now it's just <code>cat fname | wc -l</code>, and it takes very long.  Is there any solution that'd be much faster?</p>
  
  <p>I work in a high performance cluster with Hadoop installed. I was wondering if a map reduce approach could help.</p>
  
  <p>I'd like the solution to be as simple as one line run, like the <code>wc -l</code> solution, but not sure how feasible it is.</p>
  
  <p>Any ideas?</p>