Technical Standard: Networking Services (XNS), Issue 5.2 Draft 2.0
Copyright © 1999 The Open Group
Support for the headers defined in this Chapter is mandatory.
This chapter describes the contents of headers used by the X/Open Sockets
functions, macros and external variables.
Headers contain the definition of symbolic constants, common structures,
preprocessor macros and defined types.
Each function in
specifies the headers that an application must include in order to use
that function. In most cases only one header is required.
These headers are present on an application development
system; they do not have to be present on the target execution system.