SFJulie2
How do I vouch for a dead comment?
file.seek is your friend. You should not use any dynamic allocation to make it more robust (yes preallocating fixed memory size with "char circular_ring[N * MAX_SIZE]") Where N and MAX_SIZE are fixed.
Well. It requires a complete rewrite for this code to not create a risk for your users. Your code is like full of hidden landmine by lack of design.
And you know what?
It used to be standard knowledge for introduction to CS for scientific. You know why? Because no users of computers like to lose their precious data made during a very long measurement spilling huge amount of data and costing a lot of resources. (like gold, helium, molybden, electricity, time, wages of qualified operators....)
It seems like coders do not care of their users, like a builder thinking it is reasonable to build 50 store buildings on quicksands because people only judges builder by the look of their creation.
Do you live in a state of perpetual nausea? Because there is so much code out there like this...I fear it could overwhelm your life to worry about it.
I think the best we can do is just fix the stuff we want to use and ignore the rest..