[sql-server] What are named pipes?

Unix and Windows both have things called "Named pipes", but they behave differently. On Unix, a named pipe is a one-way street which typically has just one reader and one writer - the writer writes, and the reader reads, you get it?

On Windows, the thing called a "Named pipe" is an IPC object more like a TCP socket - things can flow both ways and there is some metadata (You can obtain the credentials of the thing on the other end etc).

Unix named pipes appear as a special file in the filesystem and can be accessed with normal file IO commands including the shell. Windows ones don't, and need to be opened with a special system call (after which they behave mostly like a normal win32 handle).

Even more confusing, Unix has something called a "Unix socket" or AF_UNIX socket, which works more like (but not completely like) a win32 "named pipe", being bidirectional.