SetFileApisToOEM

SetFileApisToOEM

The SetFileApisToOEM function causes a set of Win32 file functions to use the OEM character set code page. This function is useful for 8-bit console input and output operations.

VOID SetFileApisToOEM(VOID)

Parameters

This function has no parameters.

Return Values

This function has no return value.

Remarks

The SetFileApisToOEM function is complemented by the SetFileApisToANSI function, which causes the same set of Win32 file functions to use the ANSI character set code page.

The 8-bit console functions use the OEM code page by default. All other functions use the ANSI code page by default. This means that strings returned by the console functions may not be processed correctly by other functions, and vice versa. For example, if the FindFirstFileA function returns a string that contains certain extended ANSI characters, and the 8-bit console functions are set to use the OEM code page, then the WriteConsoleA function will not display the string properly.

Use the AreFileApisANSI function to determine which code page the set of file functions is currently using. Use the SetConsoleCP and SetConsoleOutputCP functions to set the code page for the 8-bit console functions.

To solve the problem of code page incompatibility, it is best to use Unicode for console applications. Console applications that use Unicode are much more versatile than those that use 8-bit console functions. Barring that solution, a console application can call the SetFileApisToOEM function to cause the set of Win32 file functions to use OEM character set strings rather than ANSI character set strings. Use the SetFileApisToANSI function to set those functions back to the ANSI code page.

SetFileApisToANSI and SetFileApisToOEM affect these Win32 functions:

_lopen	GetDriveType	LoadLibrary
CopyFile	GetFileAttributes	LoadLibraryEx
CreateDirectory	GetFullPathName	MoveFile
CreateFile	GetModuleFileName	MoveFileEx
CreateProcess	GetModuleHandle	OpenFile
DeleteFile	GetSystemDirectory	RemoveDirectory
FindFirstFile	GetTempFileName	SearchPath
FindNextFile	GetTempPath	SetCurrentDirectory
GetCurrentDirectory	GetVolumeInformation	SetFileAttributes
GetDiskFreeSpace	GetWindowsDirectory

When dealing with command lines, a console application should obtain the command line in Unicode form, and then convert it to OEM form using the relevant character-to-OEM functions. Note also that the argv function uses the ANSI character set.