Release 10.1A: OpenEdge Development:
Programming Interfaces

Sockets

The 4GL provides direct access to TCP/IP sockets, both unsecured sockets and secured sockets using the Secure Sockets Layer (SSL). Sockets provide a means to implement interprocess communications with both local and remote processes. Using 4GL sockets, you can communicate with non-4GL processes, as well as other 4GL processes. Thus, you can implement socket-based applications completely in the 4GL that otherwise require the use of C modules accessible only through the HLC or shared library interfaces.

This chapter describes how you can access TCP/IP sockets directly from the 4GL. It assumes that you are familiar with basic TCP/IP socket programming and SSL.

Note: SSL incurs heavy performance penalties, depending on the client, server, and network resources and load. For more information, see OpenEdge Getting Started: Core Business Services .

This chapter contains the following sections:

4GL for programming sockets
Overview of tasks to implement 4GL sockets
Implementing a 4GL socket server
Implementing a 4GL socket client
Read, writing, and managing sockets on clients and servers
Implementing 4GL socket security
Examples using 4GL sockets