\nA colleague of mine nominated this code for Function of the Year.\n(This is the same person who was the\n\nfirst to report that a Windows beta used a suspect URL<\/A>.)\nI have to admit that this code is pretty impressive. Of all the ways\nto check the operating system, you have to agree that sniffing\nat an undocumented implementation detail of memory-mapped files\nis certainly creative!\n<\/P>\n GetSystemDirectory(szFile, MAX_PATH);\n strcat(szFile, “\\\\MAIN.CPL”);\n hFile = CreateFile(szFile, GENERIC_READ | GENERIC_WRITE, 0,\n NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);<\/p>\n hFileMapping = CreateFileMapping(hFile, NULL, PAGE_READWRITE,\n 0, 0, NULL);<\/p>\n pbFile = (PBYTE) MapViewOfFile(hFileMapping, FILE_MAP_WRITE,\n 0, 0, 0);<\/p>\n pbFile2 = (PBYTE) MapViewOfFile(hFileMapping, FILE_MAP_WRITE,\n 0, 65536, 0);<\/p>\n if (pbFile + 65536 != pbFile2)\n return 1;<\/p>\n return 0;\n}<\/I>\n<\/PRE>\n \nNevermind that the function also leaves a file locked and leaks\ntwo handles and two views each time you call it!\n<\/P>\n \nWhat’s more, this function may erroneously report \nIt can also erroneously report \nThis particular function is from a library\nthat is used by many popular multimedia titles.\n<\/P>\n\n\/\/ following the typographical convention that code\n\/\/ in italics is wrong\nint AreWeRunningOnWindowsNT()\n{\n HANDLE hFile, hFileMapping;\n BYTE *pbFile, *pbFile2;\n char szFile[MAX_PATH];<\/p>\nFALSE<\/CODE>\non a Windows NT machine if by an amazing coincidence the\nmemory manager happens to assign the second file view to the very\nnext 64K block of memory (which it is permitted to do since\n\naddress space granularity is 64K<\/A>).\n<\/P>\nTRUE<\/CODE>\non a Windows 95 machine if the MAIN.CPL<\/CODE> file happens to be\nsmaller than 64K, or if you don’t have write permission on the file.\n(Notice that the program requests read-write access\nto the MAIN.CPL<\/CODE> file.)\n<\/P>\n