pipe
1. One of {Unix}'s buffers which can be
written to by one {asynchronous} process and read by another,
with the {kernel} suspending and waking up the sender and
receiver according to how full the pipe is. In later versions
of Unix, rather than using an anonymous kernel-managed
temporary file to implement a pipe, it can be named and is
implemented as a local {socket} pair.
2. "|" {ASCII} character 124. Used to represent a
pipe between two processes in a {shell} command line. E.g.
grep foo log | more
which feeds the output of grep into the input of more without
requiring a named temporary file and without waiting for the
first process to finish.
3. A connection to a {network}.
See also {light pipe}.
(1996-09-24)