Comment by imtomt

You could do that, but it's not really necessary, and adds extra overhead and complexity. And as the other commenter pointed out, it wouldn't work for text file types without magic numbers. I considered reading the magic number at first, but after doing more research, I've found most web servers (nginx and apache, anyway) just match based on file extension. I figure if it's good enough for them, it's good enough for ymawky.