With APAR PJ43020, the z/TPF TCP/IP stack now supports the use of UNIX domain sockets. UNIX domain sockets allow for interprocess communication on the same machine while using sockets as a transport mechanism. The implementation of UNIX domain sockets will allow application programmers another method of interprocess communication as well as make future porting efforts easier.
UNIX domain sockets differ from internet sockets in that they bind to a unique file path on the file system rather than a port and IP address combination. UNIX domain sockets support stream-oriented (TCP) and datagram-oriented (UDP) protocols and any socket application programming interface (API) that can be issued for an internet socket can be issued for a UNIX domain socket.
APAR PJ43020 also adds support for the socketpair API. Calling the socketpair API will return two connected, TCP UNIX domain sockets. This allows the application to immediately start sending and receiving data on the UNIX domain sockets returned without having to explicitly call socket, bind, listen, accept, and connect.
For more information, please see the APEDIT:
http://www-01.ibm.com/support/docview.wss?uid=swg1PJ43020