The GNU Awk User's Guide
5.7.3 Special Files for Network Communications
Starting with version 3.1 of gawk, awk programs
can open a two-way
TCP/IP connection, acting as either a client or a server.
This is done using a special file name of the form:
| | `/inet/protocol/local-port/remote-host/remote-port'
|
The protocol is one of `tcp', `udp', or `raw',
and the other fields represent the other essential pieces of information
for making a networking connection.
These file names are used with the `|&' operator for communicating
with a coprocess
(see section Two-Way Communications with Another Process).
This is an advanced feature, mentioned here only for completeness.
Full discussion is delayed until
Using gawk for Network Programming.
