title: When going over a binary file in c, do I go by bits or bytes?
body: <p>I have a long binary string which contains a number of bytes,
  I need to use <code>fseek</code> to get to a specific byte in the string.</p>
  
  <p>I know I need to calculate the offset but I'm not sure if the offset
  is calculated by bits or bytes. If I need to get to the 3rd byte for example
  I need to advance the indicator by 3 or by (3*8=)24?</p>