title: Write/Edit CSV-file (not rewrite the whole file!)
body: <p>I'm in a situation to replace some functionalities from a client that operates directly on a CSV file, which used as a config file for a system. </p>
  
  <p>Most of the cases available on search is about reading from CSV to other formats. </p>
  
  <p>Other takes the whole CSV into memory, attaching the dedicated rows and changes, then write them back to a new file (or overwrite existing). </p>
  
  <p>I would like to do this task smarter and ask for advices and code ideas. <br>
  We can presume that just one user per time, should have access to the file.<br>
  The file reads with File.ReadLines() .NET 4.<br></p>
  
  <p>A part from my sample project,</p>
  
  <pre><code>   var lines = from l in File.ReadLines("/Linq2Csv/data.csv")
                 where l.Split(',')[0].StartsWith("Jonas") //Just test 'n pick 1 line
                 select new
                 {
                   Name = l.Split(',')[0],
                   ...
  </code></pre>