Mastering Embedded Linux Programming - Second Edition

FIFOs and named pipes

FIFO and named pipe are just different terms for the same thing. They are an extension of the anonymous pipe that is used to communicate between parent and child processes when implementing pipes in the shell.

A FIFO is a special sort of file, created by the mkfifo(1) command. As with Unix sockets, the file access permissions determine who can read and write. They are unidirectional, which means that there is one reader and usually one writer, though there may be several. The data is a pure byte stream but with a guarantee of the atomicity of messages that are smaller than the buffer associated with the pipe. In other words, writes less than this size will not be split into several smaller writes and so you will read ...