GetLongPathNameTransactedW function (winbase.h)
[Microsoft strongly recommends developers utilize alternative means to achieve your application’s needs. Many scenarios that TxF was developed for can be achieved through simpler and more readily available techniques. Furthermore, TxF may not be available in future versions of Microsoft Windows. For more information, and alternatives to TxF, please see Alternatives to using Transactional NTFS.]
Converts the specified path to its long form as a transacted operation.
To perform this operation without a transaction, use the GetLongPathName function.
For more information about file and path names, see Naming Files, Paths, and Namespaces.
Syntax
DWORD GetLongPathNameTransactedW(
[in] LPCWSTR lpszShortPath,
[out] LPWSTR lpszLongPath,
[in] DWORD cchBuffer,
[in] HANDLE hTransaction
);
Parameters
[in] lpszShortPath
The path to be converted.
The path must reside on the local computer; otherwise, the function fails and the last error code is set to ERROR_TRANSACTIONS_UNSUPPORTED_REMOTE.
By default, the name is limited to MAX_PATH characters. To extend this limit to 32,767 wide characters, prepend "\\?\" to the path. For more information, see Naming Files, Paths, and Namespaces.
Tip
Starting with Windows 10, Version 1607, you can opt-in to remove the MAX_PATH limitation without prepending "\\?\". See the "Maximum Path Length Limitation" section of Naming Files, Paths, and Namespaces for details.
[out] lpszLongPath
A pointer to the buffer to receive the long path.
You can use the same buffer you used for the lpszShortPath parameter.
[in] cchBuffer
The size of the buffer lpszLongPath points to, in TCHARs.
[in] hTransaction
A handle to the transaction. This handle is returned by the CreateTransaction function.
Return value
If the function succeeds, the return value is the length, in TCHARs, of the string copied to lpszLongPath, not including the terminating null character.
If the lpBuffer buffer is too small to contain the path, the return value is the size, in TCHARs, of the buffer that is required to hold the path and the terminating null character.
If the function fails for any other reason, such as if the file does not exist, the return value is zero. To get extended error information, call GetLastError.
Remarks
On many file systems, a short file name contains a tilde (~) character. However, not all file systems follow this convention. Therefore, do not assume that you can skip calling GetLongPathNameTransacted if the path does not contain a tilde (~) character.
If a long path is not found, this function returns the name specified in the lpszShortPath parameter in the lpszLongPath parameter.
If the return value is greater than the value specified in cchBuffer, you can call the function again with a buffer that is large enough to hold the path. For an example of this case, see the Example Code section for GetFullPathName.
In Windows 8 and Windows Server 2012, this function is supported by the following technologies.
| Technology | Supported |
|---|---|
| Server Message Block (SMB) 3.0 protocol | No |
| SMB 3.0 Transparent Failover (TFO) | No |
| SMB 3.0 with Scale-out File Shares (SO) | No |
| Cluster Shared Volume File System (CsvFS) | No |
| Resilient File System (ReFS) | No |
SMB 3.0 does not support TxF.
Note
The winbase.h header defines GetLongPathNameTransacted as an alias that automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that is not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows Vista [desktop apps only] |
| Minimum supported server | Windows Server 2008 [desktop apps only] |
| Target Platform | Windows |
| Header | winbase.h (include Windows.h) |
| Library | Kernel32.lib |
| DLL | Kernel32.dll |