Gzip ActiveX Reference

Gzip

GZip compression component.

Object Creation

(Visual Basic 6.0)
Dim obj As New Gzip
(ASP)
set obj = Server.CreateObject("Chilkat.Gzip")
(VBScript)
set obj = CreateObject("Chilkat.Gzip")
(Delphi)
obj := TGzip.Create(Self);
(FoxPro)
loObject = CreateObject('Chilkat.Gzip')
(SQL Server)
EXEC @hr = sp_OACreate 'Chilkat.Gzip', @obj OUT
(Javascript)
var obj = new ActiveXObject("Chilkat.Gzip");

Properties

Comment As String

Specifies an optional comment string that can be embedded within the .gz when any Compress* method is called.

ExtraData As Variant

Optional extra-data that can be included within a .gz when a Compress* method is called.

Filename As String

The filename that is embedded within the .gz during any Compress* method call. When extracting from a .gz using applications such as WinZip, this will be the filename that is created.

LastErrorHtml As String (read-only)

Error information in HTML format for the last method called.

LastErrorText As String (read-only)

Error information in plain-text format for the last method called.

LastErrorXml As String (read-only)

Error information in XML format for the last method called.

LastMod As Date

The last-modification date/time to be embedded within the .gz when a Compress* method is called. By default, the current system date/time is used.

UseCurrentDate As Long

If set to 1, the file produced by an Uncompress* method will use the current date/time for the last-modification date instead of the date/time found within the Gzip format.

Version As String (read-only)

Version of the component, such as "1.0.0"

Methods

CompressFile(inFilename As String, outGzipFilename As String) As Long

Compresses a file to create a GZip compressed file (.gz).

Returns 1 for success, 0 for failure.

CompressFile2(inFilename As String, embeddedFilename As String, outGzipFilename As String) As Long

Compresses a file to create a GZip compressed file (.gz). inFilename is the actual filename on disk. embeddedFilename is the filename to be embedded in the .gz such that when it is un-gzipped, this is the name of the file that will be created.

Returns 1 for success, 0 for failure.

CompressFileToMem(inFilename As String) As Variant

Gzip compresses a file to an in-memory image of a .gz file.

Returns an empty Variant on failure.

Returns a zero-length byte array (as a Variant) on failure

CompressMemToFile(inData As Variant, outFilename As String) As Long

Gzip compresses and creates a .gz file from in-memory data.

Returns 1 for success, 0 for failure.

CompressMemory(inData As Variant) As Variant

Compresses in-memory data to an in-memory image of a .gz file.

Returns a zero-length byte array (as a Variant) on failure

CompressString(inString As String, outCharset As String) As Variant

Gzip compresses a string and writes the output to a byte array. The string is first converted to the charset specified by outCharset. Typical charsets are "utf-8", "iso-8859-1", "shift_JIS", etc.

Returns a zero-length byte array (as a Variant) on failure

Full List of Charset Names

CompressStringToFile(inStr As String, outCharset As String, outFilename As String) As Long

Gzip compresses a string and writes the output to a .gz compressed file. The string is first converted to the charset specified by ARG2. Typical charsets are "utf-8", "iso-8859-1", "shift_JIS", etc.

Returns 1 for success, 0 for failure.

Full List of Charset Names

Decode(encodedStr As String, encoding As String) As Variant

Decodes an encoded string and returns the original data. The encoding mode is determined by encoding. It may be "base64", "hex", "quoted-printable", or "url".

Returns a zero-length byte array (as a Variant) on failure

DeflateStringENC(inString As String, charsetName As String, outputEncoding As String) As String

Provides the ability to use the zip/gzip's deflate algorithm directly to compress a string. Internal to this method, inString is first converted to the charset specified by charsetName. The data is then compressed using the deflate compression algorithm. The binary output is then encoded according to outputEncoding. Possible values for outputEncoding are "hex", "base64", "url", and "quoted-printable".

Note: The output of this method is compressed data with no Gzip file format. Use the Compress* methods to produce Gzip file format output.

Returns a null on failure

Full List of Charset Names

Encode(byteData As Variant, encoding As String) As String

Encodes binary data to a printable string. The encoding mode is determined by encoding. It may be "base64", "hex", "quoted-printable", or "url".

Returns a null on failure

ExamineFile(inGzFilename As String) As Long

Determines if the inGzFilename is a Gzip formatted file. Returns 1 if it is a Gzip formatted file, otherwise returns 0.

ExamineMemory(inGzData As Variant) As Long

Determines if the in-memory bytes (inGzData) contain a Gzip formatted file. Returns 1 if it is Gzip format, otherwise returns 0.

InflateStringENC(inString As String, convertFromCharset As String, inputEncoding As String) As String

This the reverse of DeflateStringENC.

The input string is first decoded according to inputEncoding. (Possible values for inputEncoding are "hex", "base64", "url", and "quoted-printable".) The compressed data is then inflated, and the result is then converted from convertFromCharset (if necessary) to return a string.

Returns a null on failure

IsUnlocked() As Long

Returns 1 if the component has been unlocked.

ReadFile(filename As String) As Variant

Reads a binary file into memory and returns the byte array. Note: This method does not parse a Gzip, it is only a convenience method for reading a binary file into memory.

Returns a zero-length byte array (as a Variant) on failure

SaveLastError(filename As String)

Saves the last error information to an XML formatted file.

UnTarGz(tgzFilename As String, destDir As String, bNoAbsolute As Long) As Long

Unpacks a .tar.gz file. The ungzip and untar occur in streaming mode. There are no temporary files and the memory footprint is constant (and small) while untarring. bNoAbsolute may be 1 or 0. A value of 1 protects from untarring to absolute paths. (For example, imagine the trouble if the tar contains files with absolute paths beginning with /Windows/system32)

Returns 1 for success, 0 for failure.

UncompressFile(inFilename As String, outFilename As String) As Long

Un-Gzips a .gz file. The output filename is specified by the 2nd argument and not by the filename embedded within the .gz.

Returns 1 for success, 0 for failure.

UncompressFileToMem(inFilename As String) As Variant

Un-Gzips a .gz file directly to memory.

Returns an empty Variant on failure.

Returns a zero-length byte array (as a Variant) on failure

UncompressFileToString(gzFilename As String, charset As String) As String

Uncompresses a .gz file that contains a text file. The contents of the text file are returned as a string. The character encoding of the text file is specified by charset. Typical charsets are "iso-8859-1", "utf-8", "windows-1252", "shift_JIS", "big5", etc.

Returns a null on failure

List of Valid Charsets

UncompressMemToFile(inData As Variant, outFilename As String) As Long

Un-Gzips from an in-memory image of a .gz file to a file.

Returns 1 for success, 0 for failure.

UncompressMemory(inData As Variant) As Variant

Un-Gzips from an in-memory image of a .gz file directly into memory.

Returns an empty Variant on failure.

Returns a zero-length byte array (as a Variant) on failure

UncompressString(inData As Variant, inCharset As String) As String

The reverse of CompressString.

The bytes in inData are uncompressed, then converted from inCharset (if necessary) to return a string.

Returns a null on failure

Full List of Charset Names

UnlockComponent(b1 As String) As Long

Unlocks the component allowing for the full functionality to be used.

Returns 1 for success, 0 for failure.

WriteFile(filename As String, binaryData As Variant) As Long

A convenience method for writing a binary byte array to a file.

Returns 1 for success, 0 for failure.

XfdlToXml(xfldData As String) As String

Converts base64-gzip .xfdl data to a decompressed XML string. The xfldData contains the base64 data. This method returns the decoded/decompressed XML string.

Returns a null on failure