LZOpenFile

The LZOpenFile function creates, opens, reopens, or deletes the specified file.

INT LZOpenFile(
  LPTSTR lpFileName,       // file name
  LPOFSTRUCT lpReOpenBuf,  // file information buffer
  WORD wStyle              // action to take
);

Parameters

lpFileName

[in] Pointer to a string that specifies the name of a file.

lpReOpenBuf

[out] 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 refer to the open file.

The szPathName member of this structure contains characters from the original equipment manufacturer (OEM) character set.

wStyle

[in] Specifies the action to take. This parameter can be one or more of the following values.

Value	Meaning
OF_CANCEL	Ignored. In the Win32-based application programming interface (API), the OF_PROMPT style produces a dialog box containing a Cancel button.
OF_CREATE	Directs LZOpenFile to create a new file. If the file already exists, it is truncated to zero length.
OF_DELETE	Deletes the file.
OF_EXIST	Opens the file and then closes it to test for a file's existence.
OF_PARSE	Fills the OFSTRUCT structure but carries out no other action.
OF_PROMPT	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.
OF_READ	Opens the file for reading only.
OF_READWRITE	Opens the file for reading and writing.
OF_REOPEN	Opens the file using information in the reopen buffer.
OF_SHARE_DENY_NONE	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.
OF_SHARE_DENY_READ	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.
OF_SHARE_DENY_WRITE	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.
OF_SHARE_EXCLUSIVE	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.
OF_WRITE	Opens the file for writing only.

Return Values

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.

Note  LZOpenFile calls neither SetLastError nor SetLastErrorEx; thus, its failure does not affect a thread's last-error code.

The following is the list of the error codes that LZOpenFile can return upon failure.

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 LZEXPAND.DLL; it should not be used for other file operations.

Windows NT/ 2000: If LZOpenFile is unable to open the file specified by lpFileName, 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.

Requirements

  Windows NT/2000: Requires Windows NT 3.1 or later.
  Windows 95/98: Requires Windows 95 or later.
  Header: Declared in Lzexpand.h; include Windows.h.
  Library: Use Lz32.lib.
  Unicode: Implemented as Unicode and ANSI versions on Windows NT/2000.

See Also

Data Decompression Library Overview, Data Decompression Library Functions, LZClose, LZInit, LZRead, OFSTRUCT