C Socket application programming interface

Note: The TCP/IP C socket API is not being enhanced for IPv6. The use of the UNIX C socket library is encouraged for IPv4 application development and is required for IPv6 application development. For more information, see z/OS XL C/C++ Runtime Library Reference.

This information describes the C IPv4 socket application program interface (API) provided with TCP/IP. Use the socket routines to interface with the TCP, UDP, and IP protocols. The socket routines allow you to communicate with other programs across networks. You can, for example, use socket routines when you write a client program that must communicate with a server program running on another computer.

Topics include:

Compiler restrictions
Compiling and linking C applications
Compiler messages
Program abends
C socket implementation
C socket header files
C structures
Error messages and return codes
C socket calls
Sample C socket programs

To use the C socket API, you must know C language programming. For more information about C language programming, see z/OS XL C/C++ Programming Guide.