BUG: CreateFile with OPEN_ALWAYS Sets Last Error Incorrectly (194929)
The information in this article applies to:
- Microsoft Win32 Application Programming Interface (API), when used with:
- the operating system: Microsoft Windows NT 3.1
- the operating system: Microsoft Windows NT 3.51
- the operating system: Microsoft Windows NT 4.0
- the operating system: Microsoft Windows 2000
This article was previously published under Q194929 SYMPTOMS
If you call the CreateFile API with the OPEN_ALWAYS flag when the specified
file already exists, the API should return a valid handle and GetLastError
should return ERROR_ALREADY_EXISTS.
When the file that is being opened is being accessed using either a UNC
path name or through a mapped drive, GetLastError sometimes returns
ERROR_SUCCESS even if the file already exists.
RESOLUTION
Break up the CreateFile call with the OPEN_ALWAYS flag into two separate
calls to CreateFile.
Call CreateFile with the OPEN_EXISTING flag. If the call to CreateFile
succeeds, the file already existed. If the call to CreateFile fails, you
can call CreateFile with the OPEN_ALWAYS flag.
STATUS
Microsoft has confirmed this to be a bug in the Microsoft products listed
at the beginning of this article.
MORE INFORMATION
This error only occurs if the file is being accessed using either a UNC
path name or through a mapped drive and the file is located on a Windows NT
Server.
| Modification Type: | Minor | Last Reviewed: | 3/3/2005 |
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| Keywords: | kbbug kbFileIO kbKernBase kbpending KB194929 |
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