LZCopy function (lzexpand.h)

Article
10/13/2021

Copies a source file to a destination file. If the source file has been compressed by the Lempel-Ziv algorithm, this function creates a decompressed destination file. If the source file is not compressed, this function duplicates the original file.

Syntax

LONG LZCopy(
  [in] INT hfSource,
  [in] INT hfDest
);

Parameters

[in] hfSource

A handle to the source file.

[in] hfDest

A handle to the destination file.

Return value

If the function succeeds, the return value specifies the size, in bytes, of the destination file.

If the function fails, the return value is an LZERROR_* code. These codes have values less than zero. Note that LZCopy calls neither SetLastError nor SetLastErrorEx; thus, its failure does not affect a thread's last-error code.

The following is a list of error codes that LZCopy can return upon failure.

Return code	Description
LZERROR_BADINHANDLE	The handle identifying the source file is not valid. The file cannot be read.
LZERROR_BADOUTHANDLE	The handle identifying the destination file is not valid. The file cannot be written.
LZERROR_GLOBALLOC	The maximum number of open compressed files has been exceeded or local memory cannot be allocated.
LZERROR_GLOBLOCK	The LZ file handle cannot be locked down.
LZERROR_READ	The source file format is not valid.

There is no extended error information for this function; do not call GetLastError.

Remarks

The handles identifying the source and destination files must be retrieved by calling the LZInit or LZOpenFile function.

If the function succeeds, the file identified by the hfDest parameter is always uncompressed.

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.

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