title: How to parallelize file reading and writing
body: <p>I have a program which reads data from 2 text files and then save the result to another file. Since there are many data to be read and written which cause a performance hit, I want to parallize the reading and writing operations.</p>
  
  <p>My initial thought is, use 2 threads as an example, one thread read/write from the beginning, and another thread read/write from the middle of the file. Since my files are formatted as lines, not bytes(each line may have different bytes of data), seek by byte does not work for me. And the solution I could think of is use getline() to skip over the previous lines first, which might be not efficient.</p>
  
  <p>Is there any good way to seek to a specified line in a file? or do you have any other ideas to parallize file reading and writing?</p>
  
  <p>Environment: Win32, C++, NTFS, Single Hard Disk</p>
  
  <p>Thanks.</p>
  
  <p>-Dbger</p>