Question

I read in a file with ifstream, and I want to write out with cout how much of the file already read, in percent.

long length = 0, now = 0;
int i = 0;
double d = 0;

file.seekg( 0, std::ios::end );
length = file.teelg();
file.seekg( 0, std::ios::beg );

while ( std::getline( file, buffer ) ) {
    now = file.teelg;

    i = now / length * 100;
    d = now / length * 100;

    std::cout << length << " "      // working
              << now << " "     // working
              << ( now / length * 100 ) << " "  // not working = 0
              << i << " "           // not working = 0
              << d;         // not working = 0
}

Only if now = length shows me that it’s 100%, but every other time it fails and gives me back 0.
I can imagine, that the answer is simple as the 1*1, but now I can’t find the solution. I also tried with casting, maybe because of that’s the problem, but of course nothing.

Answer 1

Unless one of the operands is a float or double, / does integer division and discards the remainder.

Write it like this:

( (double)now / length * 100 )