15.3.5.7 Miscellaneous Issues

Windows shared libraries (DLLs) are different from typical Unix shared libraries. They require special declarations for global variables declared in a shared library. Programs which use shared libraries must generally use special macros in their header files to define these appropriately. GNU libtool can help with some shared library issues, but not all.

There are some Unix system features which are not supported under Windows: pseudo terminals, effective user ID, file modes with user/group/other permission, named FIFOs, an executable overriding functions called by shared libraries, select on anything other than sockets.

There are some Windows system features which are not supported under Unix: the Windows event loop, many graphical capabilities, some aspects of the rich set of interthread communication mechanisms, the WSAAsyncSelect function. You should keep these issues in mind when designing and writing a program which should run on both Unix and Windows.