The GNU Awk User's Guide
11.4 Using gawk with BSD Portals
Similar to the `/inet' special files, if gawk
is configured with the `--enable-portals' option
(see section Compiling gawk for Unix),
then gawk treats
files whose pathnames begin with /p as 4.4 BSD-style portals.
When used with the `|&' operator, gawk opens the file
for two-way communications. The operating system's portal mechanism
then manages creating the process associated with the portal and
the corresponding communications with the portal's process.
