I am trying to read data from file (binary). I use C++ ifstream to access the data.
The file has size around 900KB, which I can tell with:
stream.seekg(0, stream.end);
cout << stream.tellg() << endl;
stream.seekg(0, stream.beg);
cout << stream.tellg() << endl;
When I tried to read from the file, the pointer moves actually more than what I want to read. When I wrote the following code to track it (I know that the 1 byte in the buffer gets overridden):
int counter = 0;
while (stream.good()) {
stream.read(buffer, 1);
cout << stream.tellg() << " " << counter++ << " " << stream.gcount() << endl;
}
cout << counter << endl;
What surprised me was the fact that the tellg didn't increase as much as counter. Some of the output looked like this:
...
242770 25488 1
245760 25489 1
249345 25490 1
249346 25491 1
249347 25492 1
...
As you can see the position of the file pointer sometimes jumped by 1, sometimes by numbers like 2990 or 3585. Eventually the stream goes to eofbit/failbit, despite the fact that I have read less than the file size is. What is an explanation of such behaviour? NOTE: I am using windows/visual studio
