How can I read/stream a file without loading the entire file into memory?

Question

How can I read an arbitrary file and process it \"piece by piece\" (meaning byte by byte or some other chunk size that would give the best read performance) without loading

Answer 1

Here's an example of how to read a file in chunks of 1KB without loading the entire contents into memory:

const int chunkSize = 1024; // read the file by chunks of 1KB
using (var file = File.OpenRead("foo.dat"))
{
    int bytesRead;
    var buffer = new byte[chunkSize];
    while ((bytesRead = file.Read(buffer, 0, buffer.Length)) > 0)
    {
        // TODO: Process bytesRead number of bytes from the buffer
        // not the entire buffer as the size of the buffer is 1KB
        // whereas the actual number of bytes that are read are 
        // stored in the bytesRead integer.
    }
}