1. <operating system> 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
2. <character> "|" ASCII
Used to represent a pipe between two processes in a shell
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. <jargon, networking> A connection to a network
See also light pipe