LZOpenFileA function (lzexpand.h)
Creates, opens, reopens, or deletes the specified file.
Syntax
INT LZOpenFileA(
[in] LPSTR lpFileName,
[out] LPOFSTRUCT lpReOpenBuf,
[in] WORD wStyle
);
Parameters
[in] lpFileName
The name of the file.
[out] lpReOpenBuf
A pointer to the OFSTRUCT structure that is to receive information about the file when the file is first opened. The structure can be used in subsequent calls to the LZOpenFile function to see the open file.
The szPathName member of this structure contains characters from the original equipment manufacturer (OEM) character set.
[in] wStyle
The action to be taken. This parameter can be one or more of the following values.
| Value | Meaning |
|---|---|
|
Ignored. Provided only for compatibility with 16-bit Windows. Use the OF_PROMPT style to display a dialog box containing a Cancel button. |
|
Directs LZOpenFile to create a new file. If the file already exists, it is truncated to zero length. |
|
Deletes the file. |
|
Opens the file and then closes it to test for a file's existence. |
|
Fills the OFSTRUCT structure but carries out no other action. |
|
Displays a dialog box if the requested file does not exist. The dialog box informs the user that the system cannot find the file, and it contains Retry and Cancel buttons. Clicking the Cancel button directs LZOpenFile to return a file not found error message. |
|
Opens the file for reading only. |
|
Opens the file for reading and writing. |
|
Opens the file using information in the reopen buffer. |
|
Opens the file without denying other processes read or write access to the file. LZOpenFile fails if the file has been opened in compatibility mode by any other process. |
|
Opens the file and denies other processes read access to the file. LZOpenFile fails if the file has been opened in compatibility mode or has been opened for read access by any other process. |
|
Opens the file and denies other processes write access to the file. LZOpenFile fails if the file has been opened in compatibility mode or has been opened for write access by any other process. |
|
Opens the file in exclusive mode, denying other processes both read and write access to the file. LZOpenFile fails if the file has been opened in any other mode for read or write access, even by the current process. |
|
Opens the file for writing only. |
Return value
If the function succeeds and the value specified by the wStyle parameter is not OF_READ, the return value is a handle identifying the file. If the file is compressed and opened with wStyle set to OF_READ, the return value is a special file handle.
If the function fails, the return value is an LZERROR_* code. These codes have values less than zero. There is no extended error information for this function; do not call GetLastError.
| Return code/value | Description |
|---|---|
|
The handle identifying the source file is not valid. The file cannot be read. |
|
The maximum number of open compressed files has been exceeded or local memory cannot be allocated. |
Remarks
If the wStyle parameter is the OF_READ flag (or OF_READ and any of the OF_SHARE_* flags) and the file is compressed, LZOpenFile calls the LZInit function, which performs the required initialization for the decompression operations.
The handle this function returns is compatible only with the functions in Lz32.dll; it should not be used for other file operations.
If LZOpenFile is unable to open the file specified by lpFileName, on some versions of Windows it attempts to open a file with almost the same file name, except the last character is replaced with an underscore (""). Thus, if an attempt to open "MyProgram.exe" fails, LZOpenFile tries to open "MyProgram.ex". Installation packages often substitute the underscore for the last letter of a file name extension to indicate that the file is compressed. For example, "MyProgram.exe" compressed might be named "MyProgram.ex_". To determine the name of the file opened (if any), examine the szPathName member of the OFSTRUCT structure in the lpReOpenBuf parameter.
In Windows 8 and Windows Server 2012, this function is supported by the following technologies.
| Technology | Supported |
|---|---|
| Server Message Block (SMB) 3.0 protocol | Yes |
| SMB 3.0 Transparent Failover (TFO) | Yes |
| SMB 3.0 with Scale-out File Shares (SO) | Yes |
| Cluster Shared Volume File System (CsvFS) | Yes |
| Resilient File System (ReFS) | Yes |
CsvFs will do redirected IO for compressed files.
Note
The lzexpand.h header defines LZOpenFile as an alias which 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 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 XP [desktop apps only] |
| Minimum supported server | Windows Server 2003 [desktop apps only] |
| Target Platform | Windows |
| Header | lzexpand.h (include Windows.h) |
| Library | Lz32.lib |
| DLL | Lz32.dll |