title: c++ fastest way to read only last line of text file?
body: <p>I would like to read only the last line of a text file (I'm on UNIX, can use Boost). All the methods I know require scanning through the entire file to get the last line which is not efficient at all.  Is there an efficient way to get only the last line?</p>
  
  <p>Also, I need this to be robust enough that it works even if the text file in question is constantly being appended to by another process.</p>