title: Locking files in linux with c/c++
body: <p>I am wondering if you can : lock only a line or a single character in a file in linux and the rest of the file should remain accessible for other processes?
  I received a task regarding simulating transaction on a file with c/c++ under linux .
  Please give me an answer and if this answer is yes ,give me some links from where i could take a peek to make this task.</p>
  
  <p>Thanks,
  Madicemickael</p>