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.