Limitations of POSIX Applications on Windows NT

This article discusses the limitations of the Portable Operating System Interface (POSIX) applications on Windows NT. POSIX is a standard set by ANSI/IEEE to promote source level compatibility that allows applications to run on a wide variety of systems and architectures. The POSIX interface on Windows NT strictly follows the POSIX 1003.1-1990 standards.

Following are some of the POSIX limitations:

• POSIX applications only launch other POSIX applications. They can not launch DOS, OS/2, Win16 or Win32 applications.
• POSIX applications can not call any Win32 APIs. They do not have any access to DDE, OLE, memory mapped files, named pipes, windows sockets and other Win32 features.
• POSIX applications can not implicitly or explicitly load a Win32 DLL.
• POSIX applications do not have access to any networking APIs such as pipes or sockets. They are not network aware, but they can access files over the network.
• POSIX applications do not have any source level debugger support. You cannot use Windbg or the Microsoft Visual C++ debugger to debug POSIX applications on Windows NT.

For additional information, please see the following article in the Microsoft Knowledge Base:

MSDN Development Library, "Understanding Windows NT POSIX Compatibility", by Ray Cort.