Adds a directory to the search path used to locate DLLs for the application.

Syntax

BOOL WINAPI SetDllDirectory(
  __in_opt  LPCTSTR lpPathName
);

Parameters

lpPathName [in, optional]

The directory to be added to the search path. If this parameter is an empty string (""), the call removes the current directory from the default DLL search order. If this parameter is NULL, the function restores the default search order.

Return Value

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The SetDllDirectory function affects all subsequent calls to the LoadLibrary and LoadLibraryEx functions. It also effectively disables safe DLL search mode while the specified directory is in the search path.

After calling SetDllDirectory, the DLL search path is:

1. The directory from which the application loaded.
2. The directory specified by the lpPathName parameter.
3. The system directory. Use the GetSystemDirectory function to get the path of this directory. The name of this directory is System32.
4. The 16-bit system directory. There is no function that obtains the path of this directory, but it is searched. The name of this directory is System.
5. The Windows directory. Use the GetWindowsDirectory function to get the path of this directory.
6. The directories that are listed in the PATH environment variable.

To revert to the default search path used by LoadLibrary and LoadLibraryEx, call SetDllDirectory with NULL. This also restores safe DLL search mode based on the SafeDllSearchMode registry value.

To compile an application that uses this function, define _WIN32_WINNT as 0x0502 or later. For more information, see Using the Windows Headers.

Requirements

See Also

Dynamic-Link Library Search Order

GetDllDirectory

GetSystemDirectory

GetWindowsDirectory

LoadLibrary

LoadLibraryEx

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Build date: 11/19/2009