You can't trust your parents to protect you On Unix-like systems, setting sufficiently strict permissions on a dir allows one to disallow access to its content. Right? Turns out to be untrue on both macOS and Linux. Enter inodes trickery.
The brokenness of the sendfile() system call The sendfile() system call has a bad reputation. In theory it is pretty nice: the system call allows you to send a file over a socket, without having to read out the file and writing to the socket block-by-block. Instead