Reading data from text file and Splitting & distinguish them in C++

I am storing data (distance, amplitude & angle) from a sensor into a text file. Number of data is very huge(252000 in a second). I am saving in following format: (see the screenshot for better idea)

Timestamp
distance amplitude angle; distance amplitude angle; ...
Timestamp
distance amplitude angle; distance amplitude angle; ...

Now, I want to read all these data from the text file and want separate & distinguish them like the first one is always 'distance' second is 'amplitude' and the third is 'angle' and than ';'.
How do I do this..??