Fastest way to read every 30th byte of large binary file?

Question

What is the fastest way to read every 30th byte of a large binary file (2-3 GB)? I\'ve read there are performance problems with fseek because of I/O buffers, but I don\'t wa

Answer 1

What I'd suggest is that you create a buffer of a few thousand bytes, read every 30th byte from it, reload the buffer with the next few thousand bytes, and continue until you reach the eof. That way the amount of data read into memory is limited, and you also don't have to read from the file as often. You'll find that the larger the buffer you create, the faster it'll be.

Edit: Actually, as suggested below, you'll probably want to make your buffer a few hundred kb's, not a few thousand bytes (like I said - bigger buffer = faster file read).