FIFOs - who uses them?

[gwyn%brl-vld at sri-unix.UUCP]

From:      Doug Gwyn (VLD/VMB) <gwyn at brl-vld>

A FIFO is a "named pipe".  I.e., it acts like a pipe but can be opened
by its name in the file system rather than having to be passed as an
open fd created by a parent process.

The additional kernel code to support FIFOs was minimal, which may
have something to do with this facility being there; it integrates
nicely with the existing pipe and file facilities.

This idea was tried by RAND Corp. several years ago but wasn't
implemented as cleanly.

One could use a FIFO for any server daemon; the known file name would
serve as a port to send requests to.  Berkeley sockets could also be
used this way.