LibC allows you to choose between ANSI, POSIX, NetWare direct file system (DFS), and NKS interfaces for directory and file I/O. The decision on which interface to use should be based on portability and performance.
ANSI (ISO/IEC 9899:1999) and POSIX (ISO/IEC 9945:1996) are generally portable across multiple operating systems and might already be in use in your code. NKS interfaces are portable across NetWare® platforms and are useful when greater performance is needed or when they provide increased functionality. These interfaces sit right on top of the underlying file systems and provide, as will become apparent, advanced functionality over ANSI and POSIX.
This section describes how all the interfaces interact with the following features:
The Direct File System functions provide a way to bypassing the NetWare caching subsystem and read and write directly to the disk. For more information, see Section 13.4, Direct File System Overview.
The NKS functions provide access to information beyond what is available in standard I/O interfaces and to NetWare specific information. For more information, see NKS Overview.