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

You almost certainly don't need to worry about it. The runtime may well buffer the last block that it read for each file handle. Even if it doesn't, the operating system is caching file accesses for you.

That said, if you read a block at a time, you do save on call overheads to the fseek and fread functions. The bigger the block you read at once, the more you save on call overheads - though other costs obviously start making themselves felt beyond a certain point.