title: reading values from file, line by line in c
body: <p>I have to open and read a .dat-file with sensorvalues. Every line has a new value I have to read, like:</p>
  
  <pre><code>timestamp, value
  000000001, 1.233
  000000002, 1.345
  ...
  </code></pre>
  
  <p>I have to write a function which returns everytime i call it a new sensorvalue.
  I know how to read whole files, put I dont know how to implement something like a linepointer (who tells me which line to read next) or something like that. 
  The timestamps are NOT regulary, so I think i cant use them to get the newest value.</p>
  
  <p>Hope you understand my problem and can help me, thanks!</p>