# Gzip Component

The Gzip component implements a gzip compressor and decompressor. It is compliant with RFC 1952 and compatible with the UNIX gzip and gunzip utilities.

## Syntax

```text
TipzGzip
```

## Remarks

The gzip file format is typically used only to archive a single file. Accordingly, the operation of the component is simpler than that of the other components.

To compress with the component, set [ArchiveFile](#archivefile-property-gzip-component) to the name of the gzip file to be created, and [FileDecompressedName](#filedecompressedname-property-gzip-component) to the name of the file to be compressed. Finally, invoke [Compress](#compress-method-gzip-component). To extract the file, first set [ArchiveFile](#archivefile-property-gzip-component). [FileDecompressedName](#filedecompressedname-property-gzip-component) may then be set; if not, it will automatically be set from the gzip file headers. Finally, invoke the [Extract](#extract-method-gzip-component) or [Compress](#compress-method-gzip-component) method.

.tar.gz files may be created or extracted in one step by using the **Tar** component. See the documentation for **Tar** for more details.

**Example (Creating a Gzip File)**

```text
ZipControl.ArchiveFile = "c:\test.gz"
ZipControl.FileDecompressedName = "c:\test.txt"
ZipControl.Compress()
```

 **Example (Extracting from a Gzip File)**

```text
ZipControl.ArchiveFile = "c:\test.gz"
ZipControl.Scan()
ZipControl.FileDecompressedName = "c:\test.txt"
ZipControl.Extract()
```

## Property List

*The following is the full list of the properties of the component with short descriptions. Click on the links for further details.*

|  |  |
| --- | --- |
| [ArchiveFile](#archivefile-property-gzip-component) | The name of the zip, gzip, tar, or jar archive. |
| [CompressionLevel](#compressionlevel-property-gzip-component) | The compression level to use. |
| [CompressionMethod](#compressionmethod-property-gzip-component) | The compression method for the component to use. |
| [ExtractToPath](#extracttopath-property-gzip-component) | A base path to decompress to. |
| [FileCompressedDate](#filecompresseddate-property-gzip-component) | The date and time of the compressed file, as stored within the gzip archive. |
| [FileCompressedName](#filecompressedname-property-gzip-component) | Filename, as stored inside of the archive. |
| [FileDecompressedName](#filedecompressedname-property-gzip-component) | File name to decompress to, or compress from. |
| [FileDecompressedSize](#filedecompressedsize-property-gzip-component) | Gets the size of the file, as decompressed outside the archive. |
| [FileInputData](#fileinputdata-property-gzip-component) | The data of the file to be compressed. |
| [GzipData](#gzipdata-property-gzip-component) | (Decompression only) The gzip file contents as a byte array. |
| [HasMoreData](#hasmoredata-property-gzip-component) | Shows whether or not there is more data in the gzip archive. |

## Method List

*The following is the full list of the methods of the component with short descriptions. Click on the links for further details.*

|  |  |
| --- | --- |
| [Abort](#abort-method-gzip-component) | Aborts the current operation. |
| [Append](#append-method-gzip-component) | Adds specified file to an existing archive. |
| [Compress](#compress-method-gzip-component) | Creates the compressed gzip archive. |
| [Config](#config-method-gzip-component) | Sets or retrieves a configuration setting. |
| [Extract](#extract-method-gzip-component) | Extracts the compressed file from the gzip archive. |
| [ExtractAll](#extractall-method-gzip-component) | Extracts all files from the compressed archive. |
| [Reset](#reset-method-gzip-component) | Resets the component. |
| [Scan](#scan-method-gzip-component) | Scans the compressed archive. |

## Event List

*The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.*

|  |  |
| --- | --- |
| [BeginFile](#beginfile-event-gzip-component) | Fired before a file is processed. |
| [EndFile](#endfile-event-gzip-component) | Fired after a file is processed. |
| [Error](#error-event-gzip-component) | Information about non-fatal errors. |
| [Overwrite](#overwrite-event-gzip-component) | Fired whenever a file exists and may be overwritten. |
| [Progress](#progress-event-gzip-component) | Fired as progress is made. |

## Config Settings

*The following is a list of config settings for the component with short descriptions. Click on the links for further details.*

|  |  |
| --- | --- |
| [FileComment](#FileComment) | Holds the comment associated with the archive. |
| [PreserveModifiedTime](#PreserveModifiedTime) | Whether or not to preserve the original modified time on extracted files. |
| [WriteToProgressEvent](#WriteToProgressEvent) | Whether or not to write data to the Progress Event. |
| [BuildInfo](#BuildInfo) | Information about the product's build. |
| [CodePage](#CodePage) | The system code page used for Unicode to Multibyte translations. |
| [LicenseInfo](#LicenseInfo) | Information about the current license. |
| [MaskSensitiveData](#MaskSensitiveData) | Whether sensitive data is masked in log messages. |
| [UseInternalSecurityAPI](#UseInternalSecurityAPI) | Whether or not to use the system security libraries or an internal implementation. |

# ArchiveFile Property ([Gzip](#gzip-component) Component)

The name of the zip, gzip, tar, or jar archive.

## Syntax

*C++ Builder Syntax*

```text
__property String ArchiveFile = { read=FArchiveFile, write=FSetArchiveFile };
```

## Default Value

""

## Remarks

This property specifies the name of the archive to be read or written. This property is required when extracting files.

When [Scan](#scan-method-gzip-component), [Extract](#extract-method-gzip-component), or [ExtractAll](#extractall-method-gzip-component) is invoked, the file specified by ArchiveFile will be opened for read. If the file does not exist, a trappable error will be generated.

When [Compress](#compress-method-gzip-component) is called, the file named by ArchiveFile will be written; if a file of this name already exists the [Overwrite](#overwrite-event-gzip-component) event will be fired. If ArchiveFile is set to the empty string (""), the archive will not be written to disk, and will be provided only through the [Progress](#progress-event-gzip-component) event.

The filename may be specified with or without a path. Paths may be relative or absolute, and should be specified in the format native to the host operating system. The filename should be specified with the appropriate extension (such as "zip"); an extension will not automatically be appended by the component.

If the file cannot be read, or written, as appropriate, a trappable error will be generated.

**Example (Creating an Archive)**

```text
ZipControl.ArchiveFile = "c:\test.zip"
ZipControl.RecurseSubdirectories = true
ZipControl.IncludeFiles("c:\foo\*")
ZipControl.Compress()
```

NOTE: an archive already open for read may be closed by setting ArchiveFile to the empty string ("").

## Data Type

String

# CompressionLevel Property ([Gzip](#gzip-component) Component)

The compression level to use.

## Syntax

*C++ Builder Syntax*

```text
__property int CompressionLevel = { read=FCompressionLevel, write=FSetCompressionLevel };
```

## Default Value

4

## Remarks

This property specifies the level of compression to be used, between 1 and 6. Higher values will cause the component to compress better; lower values will cause the component to compress faster.

Storing without compression is not supported for **Gzip**.

## Data Type

Integer

# CompressionMethod Property ([Gzip](#gzip-component) Component)

The compression method for the component to use.

## Syntax

*C++ Builder Syntax*

```text
__property TipzGzipCompressionMethods CompressionMethod = { read=FCompressionMethod, write=FSetCompressionMethod };
enum TipzGzipCompressionMethods {
  cmgDeflate=0,
  cmgLZCCompress=1
};
```

## Default Value

cmgDeflate

## Remarks

By default, the component uses the Deflate compression method described in rfc 1952. When set to LZC compress method, the component will use a variation of the method described by the LZW (Lempel-Ziv-Welch) algorithm that is compatible with Unix's compress utility.

## Data Type

Integer

# ExtractToPath Property ([Gzip](#gzip-component) Component)

A base path to decompress to.

## Syntax

*C++ Builder Syntax*

```text
__property String ExtractToPath = { read=FExtractToPath, write=FSetExtractToPath };
```

## Default Value

""

## Remarks

Setting the ExtractToPath property affects the operation of the [Extract](#extract-method-gzip-component) and [ExtractAll](#extractall-method-gzip-component) methods. Setting this property to a nonempty string will cause all decompressed files to be written to the specified path. If pathnames are given in the values of [FileDecompressedName](#filedecompressedname-property-gzip-component) they will be regarded as relative to ExtractToPath.

If the specified directory does not exist, it will be created when extraction is done.

ExtractToPath should always be specified in the format native to the host operating system, and with a trailing slash or backslash. If the path is specified otherwise, it will be immediately converted and stored in the converted format. For example, "/temp" would be immediately converted to "\temp\" on a Windows system.

**Example (Extracting from an Archive)**

```text
ZipControl.ArchiveFile = "c:\temp.zip"
ZipControl.ExtractToPath = "c:\extracted\"
ZipControl.ExtractAll()
```

## Data Type

String

# FileCompressedDate Property ([Gzip](#gzip-component) Component)

The date and time of the compressed file, as stored within the gzip archive.

## Syntax

*C++ Builder Syntax*

```text
__property __int64 FileCompressedDate = { read=FFileCompressedDate };
```

## Default Value

0

## Remarks

FileCompressedDate contains the last modified date of the file, as stored within the archive (it does not generally correspond to when the file was compressed).

FileCompressedDate is returned in a platform-specific format. The **Java** and other editions will return the number of milliseconds since January 1, 1970, 00:00:00. This value may be passed directly to the *java.util.Date* constructor to create a *java.util.Date* object representing this date.

The **.NET** Edition will return the number of ticks, or 100-nanosecond intervals, since January 1, 0001, 00:00:00. This value may be passed directly to the *System.DateTime* constructor to create a *System.DateTime* object representing this date.

Reading the value of this property will return a meaningful value only after a call to [Scan](#scan-method-gzip-component) or [Extract](#extract-method-gzip-component). If a meaningful value is not available this property will return a value of 0.

This property is read-only and not available at design time.

## Data Type

Long64

# FileCompressedName Property ([Gzip](#gzip-component) Component)

Filename, as stored inside of the archive.

## Syntax

*C++ Builder Syntax*

```text
__property String FileCompressedName = { read=FFileCompressedName, write=FSetFileCompressedName };
```

## Default Value

""

## Remarks

FileCompressedName contains the name of the compressed file, as stored within the gzip header.

This field should generally be set with a relative path or with no path at all. The exact interpretation of the path is left to the decompression software; generally, pathnames will be interpreted as relative to a base directory, and these subdirectories will be created as needed. Absolute pathnames (paths beginning with a */* character) will not be interpreted correctly by the component, and may or may not be interpreted correctly by other decompression software.

Paths should be specified in standard (UNIX) format. They may also be specified in the format native to the host operating system, in which case they will be immediately converted.

It is not usually necessary to manually set the value of this property; it will be assigned by [Compress](#compress-method-gzip-component) if it is not specified, and it will always be written by a call to [Scan](#scan-method-gzip-component) or [Extract](#extract-method-gzip-component).

## Data Type

String

# FileDecompressedName Property ([Gzip](#gzip-component) Component)

File name to decompress to, or compress from.

## Syntax

*C++ Builder Syntax*

```text
__property String FileDecompressedName = { read=FFileDecompressedName, write=FSetFileDecompressedName };
```

## Default Value

""

## Remarks

FileDecompressedName contains the name of the file in the archive, as stored on the file system, outside the archive.

When compressing a file, this property should be specified with a path, if necessary, to allow the file to be found by the component. If the file cannot be found when [Compress](#compress-method-gzip-component) is called, a trappable error will be generated, and the archive will not be correctly written.

When decompressing files, this property may be set after calling [Scan](#scan-method-gzip-component) and prior to calling [Extract](#extract-method-gzip-component). If this property is set to the empty string when [Extract](#extract-method-gzip-component) is called, [Extract](#extract-method-gzip-component) will automatically set this property to an appropriate value.

NOTE: If [Scan](#scan-method-gzip-component) is not called before [Extract](#extract-method-gzip-component), the component will internally call the method and any value in FileDecompressedName will be overwritten.

 Paths on the local file system should be specified in the format native to the host operating system. They may also be specified in standard (UNIX) format, in which case they will be immediately converted.

## Data Type

String

# FileDecompressedSize Property ([Gzip](#gzip-component) Component)

Gets the size of the file, as decompressed outside the archive.

## Syntax

*C++ Builder Syntax*

```text
__property __int64 FileDecompressedSize = { read=FFileDecompressedSize };
```

## Default Value

-1

## Remarks

This property holds the decompressed size of the file. If an archive is open for read (i.e. has been scanned or decompressed), this information will be read from the archive headers. If an archive is not open for read, the component will retrieve the information for the corresponding value of DecompressedName from the local file system.

A value of -1 will be returned in case of an I/O error.

This property is read-only and not available at design time.

## Data Type

Long64

# FileInputData Property ([Gzip](#gzip-component) Component)

The data of the file to be compressed.

## Syntax

*C++ Builder Syntax*

```text
__property String FileInputData = { read=FFileInputData, write=FSetFileInputData };
__property DynamicArray<Byte> FileInputDataB = { read=FFileInputDataB, write=FSetFileInputDataB };
```

## Default Value

""

## Remarks

When this property is set, the component will read in the data from this property instead of reading from the file contained in the [FileDecompressedName](#filedecompressedname-property-gzip-component) property.

This property is not available at design time.

## Data Type

Byte Array

# GzipData Property ([Gzip](#gzip-component) Component)

(Decompression only) The gzip file contents as a byte array.

## Syntax

*C++ Builder Syntax*

```text
__property String GzipData = { write=FSetGzipData };
__property DynamicArray<Byte> GzipDataB = { write=FSetGzipDataB };
```

## Default Value

""

## Remarks

Normally you should set [ArchiveFile](#archivefile-property-gzip-component) before invoking [Scan](#scan-method-gzip-component) or [Extract](#extract-method-gzip-component). If you prefer to read the gzip file from memory you may set GzipData instead. GzipData should be set to the entire contents of the gzip file; this will allow you to read from the archive without writing any temporary files to disk.

If you would like to extract data from the archive without ever writing to disk you should also set [WriteToProgressEvent](#WriteToProgressEvent) to true, and after invoking [Scan](#scan-method-gzip-component), you should set the value of [FileDecompressedName](#filedecompressedname-property-gzip-component) to an empty string. Then, when you invoke [Extract](#extract-method-gzip-component) (or [ExtractAll](#extractall-method-gzip-component)) the data will be provided in the [Progress](#progress-event-gzip-component) event.

This property is write-only. Note that modifying a gzip file stored in GzipData is not supported, so [Append](#append-method-gzip-component) will throw exceptions.

This property is write-only and not available at design time.

## Data Type

Byte Array

# HasMoreData Property ([Gzip](#gzip-component) Component)

Shows whether or not there is more data in the gzip archive.

## Syntax

*C++ Builder Syntax*

```text
__property bool HasMoreData = { read=FHasMoreData };
```

## Default Value

false

## Remarks

The Gzip format described in RFC 1952 allows multiple gzipped data members to be concatenated into a single file. However, due to the nature of the algorithm it is impossible to determine the number of data members until after the entire archive has been decompressed. The HasMoreData property can be used to cycle through the archive and extract each file.

Simply set the [ArchiveFile](#archivefile-property-gzip-component) and [ExtractToPath](#extracttopath-property-gzip-component) properties, then call [Extract](#extract-method-gzip-component) as long as the component has available data.

**Note**: the component will not update [FileDecompressedName](#filedecompressedname-property-gzip-component) unless you call [Scan](#scan-method-gzip-component) or manually set [FileDecompressedName](#filedecompressedname-property-gzip-component) on each loop before calling [Extract](#extract-method-gzip-component).

**Example (Extracting Multiple Files)**

```text
ZipControl.ArchiveFile = "c:\temp.zip"
ZipControl.ExtractToPath = "c:\extracted\"
Do
  ZipControl.Scan()
  //here you may inspect the file name in FileDecompressedName prior to extraction
  ZipControl.Extract()
While ZipControl.HasMoreData
```

This property is read-only.

## Data Type

Boolean

# Abort Method ([Gzip](#gzip-component) Component)

Aborts the current operation.

## Syntax

*C++ Builder Syntax*

```text
void __fastcall Abort();
```

## Remarks

Abort may be used to immediately interrupt compression or decompression. Any files partially written by the component will be deleted.

# Append Method ([Gzip](#gzip-component) Component)

Adds specified file to an existing archive.

## Syntax

*C++ Builder Syntax*

```text
void __fastcall Append();
```

## Remarks

The file contained in the [FileDecompressedName](#filedecompressedname-property-gzip-component) property will be appended to the archive specified by [ArchiveFile](#archivefile-property-gzip-component).

This method may only be used to add files to an existing archive. To add files to a new archive, [Compress](#compress-method-gzip-component) method should be used.

# Compress Method ([Gzip](#gzip-component) Component)

Creates the compressed gzip archive.

## Syntax

*C++ Builder Syntax*

```text
void __fastcall Compress();
```

## Remarks

Invoking Compress creates the archive specified by [ArchiveFile](#archivefile-property-gzip-component). When the method is called, the file specified by [FileDecompressedName](#filedecompressedname-property-gzip-component) will be opened, and the file specified by [ArchiveFile](#archivefile-property-gzip-component) will contain the compressed output.

The filename to be stored within the archive is given by [FileCompressedName](#filecompressedname-property-gzip-component). If this property is set to the empty string, it will be set to an appropriate value automatically; the component always writes a filename in the gzip headers.

As the data is compressed the [Progress](#progress-event-gzip-component) event will be fired at regular intervals. This event may be used to stream out the gzip file, or to display a progress bar to the user.

# Config Method ([Gzip](#gzip-component) Component)

Sets or retrieves a configuration setting.

## Syntax

*C++ Builder Syntax*

```text
String __fastcall Config(String ConfigurationString);
```

## Remarks

Config is a generic method available in every component. It is used to set and retrieve [configuration settings](#config-settings-gzip-component) for the component.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these *internal properties* is provided through the Config method.

To set a configuration setting named *PROPERTY*, you must call *Config("PROPERTY=VALUE")*, where *VALUE* is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a [configuration setting](#config-settings-gzip-component), you must call *Config("PROPERTY")*. The value will be returned as a string.

# Extract Method ([Gzip](#gzip-component) Component)

Extracts the compressed file from the gzip archive.

## Syntax

*C++ Builder Syntax*

```text
void __fastcall Extract();
```

## Remarks

Invoking Extract decompresses the archive specified by [ArchiveFile](#archivefile-property-gzip-component). The compressed file will be extracted, and written to disk. Also, [FileCompressedName](#filecompressedname-property-gzip-component) will be set to the filename found in the archive.

If [FileDecompressedName](#filedecompressedname-property-gzip-component) is set to a nonempty string the file will be written there. Otherwise the component will automatically set [FileDecompressedName](#filedecompressedname-property-gzip-component) to an appropriate value:

If a filename (i.e., [FileCompressedName](#filecompressedname-property-gzip-component)) is stored in the gzip headers, this filename will be used.

Otherwise, if [ArchiveFile](#archivefile-property-gzip-component) ends in ".gz", this filename, less the ".gz" extension will be used. If there are multiple files in the archive, the current 0-based file index will be appended to all files after the first file to differentiate between multiple files. For instance "test.gz" would become "test" for the first file and "test.gz" would become "test.1" for the second file in the archive.

If neither of these two conditions holds, ".unzipped" will be appended to [ArchiveFile](#archivefile-property-gzip-component).

# ExtractAll Method ([Gzip](#gzip-component) Component)

Extracts all files from the compressed archive.

## Syntax

*C++ Builder Syntax*

```text
void __fastcall ExtractAll();
```

## Remarks

ExtractAll extracts all files from the archive. The file(s) will be extracted to the directory specified by [ExtractToPath](#extracttopath-property-gzip-component), and given the names found in the archive or specified by [FileDecompressedName](#filedecompressedname-property-gzip-component).

If [Scan](#scan-method-gzip-component) has not been invoked when ExtractAll is called, [Scan](#scan-method-gzip-component) will automatically be invoked, and the [FileCompressedName](#filecompressedname-property-gzip-component) and [FileDecompressedName](#filedecompressedname-property-gzip-component) properties will be set to the values found in the archive. To manually set the decompressed filenames, [Scan](#scan-method-gzip-component) should be invoked before setting [FileDecompressedName](#filedecompressedname-property-gzip-component).

The [BeginFile](#beginfile-event-gzip-component) and [EndFile](#endfile-event-gzip-component) events will be fired before and after each file is extracted, and the [Progress](#progress-event-gzip-component) event will be fired as the data is extracted. If [WriteToProgressEvent](#WriteToProgressEvent) is set to true, the decompressed data will be streamed out through the [Progress](#progress-event-gzip-component) event.

**Example (Extracting from an Archive)**

```text
ZipControl.ArchiveFile = "c:\temp.zip"
ZipControl.ExtractToPath = "c:\extracted\"
ZipControl.ExtractAll()
```

# Reset Method ([Gzip](#gzip-component) Component)

Resets the component.

## Syntax

*C++ Builder Syntax*

```text
void __fastcall Reset();
```

## Remarks

Reset resets the state of the component. All properties will be set to their default values, and any files open will be closed.

# Scan Method ([Gzip](#gzip-component) Component)

Scans the compressed archive.

## Syntax

*C++ Builder Syntax*

```text
void __fastcall Scan();
```

## Remarks

This method will scan the gzip archive specified by [ArchiveFile](#archivefile-property-gzip-component). The archive will be read, the header will be checked, and the stored filename will be written to [FileCompressedName](#filecompressedname-property-gzip-component).

Unlike in the **Zip**, **Tar**, and **Jar** components, it is never necessary to invoke this method, and it will not be automatically invoked by [Extract](#extract-method-gzip-component). Suggested uses for this method would be to check that the file is a gzip file, or to determine an appropriate value for [FileDecompressedName](#filedecompressedname-property-gzip-component).

# BeginFile Event ([Gzip](#gzip-component) Component)

Fired before a file is processed.

## Syntax

*C++ Builder Syntax*

```text
typedef struct {
  int Index;
  bool Skip;
} TipzGzipBeginFileEventParams;
typedef void __fastcall (__closure *TipzGzipBeginFileEvent)(System::TObject* Sender, TipzGzipBeginFileEventParams *e);
__property TipzGzipBeginFileEvent OnBeginFile = { read=FOnBeginFile, write=FOnBeginFile };
```

## Remarks

BeginFile is fired before compression or decompression begins. *Index* will contain 0.

You may use the *Skip* parameter to tell the component to skip the file when appending or decompressing.

# EndFile Event ([Gzip](#gzip-component) Component)

Fired after a file is processed.

## Syntax

*C++ Builder Syntax*

```text
typedef struct {
  int Index;
} TipzGzipEndFileEventParams;
typedef void __fastcall (__closure *TipzGzipEndFileEvent)(System::TObject* Sender, TipzGzipEndFileEventParams *e);
__property TipzGzipEndFileEvent OnEndFile = { read=FOnEndFile, write=FOnEndFile };
```

## Remarks

EndFile is fired when compression or decompression finishes. *Index* will contain 0.

# Error Event ([Gzip](#gzip-component) Component)

Information about non-fatal errors.

## Syntax

*C++ Builder Syntax*

```text
typedef struct {
  String Description;
  int ErrorCode;
  int Index;
  String FileName;
  bool Ignore;
} TipzGzipErrorEventParams;
typedef void __fastcall (__closure *TipzGzipErrorEvent)(System::TObject* Sender, TipzGzipErrorEventParams *e);
__property TipzGzipErrorEvent OnError = { read=FOnError, write=FOnError };
```

## Remarks

The Error event is fired when non-fatal errors occur during compression or decompression. Note that if this event is fired during decompression this may indicate that the archive is corrupt.

By default these errors will cause the component to fail with an exception. The exception may be overridden by setting *Ignore* to true. This will cause the error to be ignored, the file will be skipped if necessary, and the component will continue operation.

*ErrorCode* will correspond to one of the following errors:

|  |  |
| --- | --- |
| 1 | Bad or missing CRC-32 checksum. |
| 2 | Failed to set creation date of a file. |
| 111 | Can't open file for read (skipping). |

*Description* contains a textual description of the error. *Index* and *FileName* contain the array index (where appropriate) and filename of the file being processed at the time of the error.

# Overwrite Event ([Gzip](#gzip-component) Component)

Fired whenever a file exists and may be overwritten.

## Syntax

*C++ Builder Syntax*

```text
typedef struct {
  String FileName;
  bool Overwrite;
} TipzGzipOverwriteEventParams;
typedef void __fastcall (__closure *TipzGzipOverwriteEvent)(System::TObject* Sender, TipzGzipOverwriteEventParams *e);
__property TipzGzipOverwriteEvent OnOverwrite = { read=FOnOverwrite, write=FOnOverwrite };
```

## Remarks

Overwrite is fired when a file is about to be overwritten, and would overwrite an existing file. The event is fired during decompression.

*FileName* contains the full name of the file, specified with its pathname.

*Overwrite* specifies whether or not the file will be overwritten. For Zip, Jar, and Tar, this is equal by default to the value of the OverwriteFiles property. For Gzip, this value defaults to true.

Either of the parameters may be changed when the event is fired. Changing the value of *Overwrite* will override the default behavior of the component, and cause the file to be overwritten or not overwritten, depending on the value set. If *FileName* is changed, the value of *Overwrite* will be ignored, and the file will be written with the specified name. If a file of the new name also exists this file will be silently overwritten.

# Progress Event ([Gzip](#gzip-component) Component)

Fired as progress is made.

## Syntax

*C++ Builder Syntax*

```text
typedef struct {
  String Data;
  DynamicArray<Byte> DataB;
  String FileName;
  __int64 BytesProcessed;
  int PercentProcessed;
} TipzGzipProgressEventParams;
typedef void __fastcall (__closure *TipzGzipProgressEvent)(System::TObject* Sender, TipzGzipProgressEventParams *e);
__property TipzGzipProgressEvent OnProgress = { read=FOnProgress, write=FOnProgress };
```

## Remarks

The Progress event is automatically fired as compression or decompression is performed. When [WriteToProgressEvent](#WriteToProgressEvent) is true, the output data is provided through the *Data* parameter, allowing for it to be streamed out.

*FileName* contains the name of the file being written. If no file is being written, *FileName* will contain an empty string, and the output data will be provided exclusively through this event.

*BytesProcessed* contains the total number of uncompressed bytes processed. *PercentProcessed* contains the percent of uncompressed bytes processed, corresponding roughly to the running time of the operation.

For **Gzip** extraction only, *BytesProcessed* and *PercentProcessed* will reflect the number of compressed bytes extracted, as it is generally impossible to predetermine the total uncompressed size.

If [WriteToProgressEvent](#WriteToProgressEvent) is false, *Data* will contain null.

# Config Settings ([Gzip](#gzip-component) Component)

 The component accepts one or more of the following *configuration settings*. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these *internal properties* is provided through the [Config](#config-method-gzip-component) method.

### Gzip Config Settings

**FileComment**: Holds the comment associated with the archive.When compressing this may be set to include a comment in the archive. This will also hold the comment associated with an archive after calling [Scan](#scan-method-gzip-component).

**PreserveModifiedTime**: Whether or not to preserve the original modified time on extracted files.Specifies whether or not the modified time of the extracted files use the current time or the original time of the file in the archive.

When set to True (default) the extracted files will have the same modified time as the original file.

When set to False the modified time on the extracted files will be set to the current time.

**WriteToProgressEvent**: Whether or not to write data to the Progress Event.If [WriteToProgressEvent](#WriteToProgressEvent) is set to true, then all data produced through invocations of [Extract](#extract-method-gzip-component), [ExtractAll](#extractall-method-gzip-component), and [Compress](#compress-method-gzip-component) will be written to the [Progress](#progress-event-gzip-component) event as well as to disk. Applications may stream out the compressed or decompressed data by trapping this event and copying the data.

If [WriteToProgressEvent](#WriteToProgressEvent) is set to false, the data will not be streamed out, and the *Data* parameter of the [Progress](#progress-event-gzip-component) event will contain null.

By default, this config is set to false.

### Base Config Settings

**BuildInfo**: Information about the product's build.When queried, this setting will return a string containing information about the product's build.

**CodePage**: The system code page used for Unicode to Multibyte translations.The default code page is Unicode UTF-8 (65001).

The following is a list of valid code page identifiers:

|  |  |
| --- | --- |
| Identifier | Name |
| 037 | IBM EBCDIC - U.S./Canada |
| 437 | OEM - United States |
| 500 | IBM EBCDIC - International |
| 708 | Arabic - ASMO 708 |
| 709 | Arabic - ASMO 449+, BCON V4 |
| 710 | Arabic - Transparent Arabic |
| 720 | Arabic - Transparent ASMO |
| 737 | OEM - Greek (formerly 437G) |
| 775 | OEM - Baltic |
| 850 | OEM - Multilingual Latin I |
| 852 | OEM - Latin II |
| 855 | OEM - Cyrillic (primarily Russian) |
| 857 | OEM - Turkish |
| 858 | OEM - Multilingual Latin I + Euro symbol |
| 860 | OEM - Portuguese |
| 861 | OEM - Icelandic |
| 862 | OEM - Hebrew |
| 863 | OEM - Canadian-French |
| 864 | OEM - Arabic |
| 865 | OEM - Nordic |
| 866 | OEM - Russian |
| 869 | OEM - Modern Greek |
| 870 | IBM EBCDIC - Multilingual/ROECE (Latin-2) |
| 874 | ANSI/OEM - Thai (same as 28605, ISO 8859-15) |
| 875 | IBM EBCDIC - Modern Greek |
| 932 | ANSI/OEM - Japanese, Shift-JIS |
| 936 | ANSI/OEM - Simplified Chinese (PRC, Singapore) |
| 949 | ANSI/OEM - Korean (Unified Hangul Code) |
| 950 | ANSI/OEM - Traditional Chinese (Taiwan; Hong Kong SAR, PRC) |
| 1026 | IBM EBCDIC - Turkish (Latin-5) |
| 1047 | IBM EBCDIC - Latin 1/Open System |
| 1140 | IBM EBCDIC - U.S./Canada (037 + Euro symbol) |
| 1141 | IBM EBCDIC - Germany (20273 + Euro symbol) |
| 1142 | IBM EBCDIC - Denmark/Norway (20277 + Euro symbol) |
| 1143 | IBM EBCDIC - Finland/Sweden (20278 + Euro symbol) |
| 1144 | IBM EBCDIC - Italy (20280 + Euro symbol) |
| 1145 | IBM EBCDIC - Latin America/Spain (20284 + Euro symbol) |
| 1146 | IBM EBCDIC - United Kingdom (20285 + Euro symbol) |
| 1147 | IBM EBCDIC - France (20297 + Euro symbol) |
| 1148 | IBM EBCDIC - International (500 + Euro symbol) |
| 1149 | IBM EBCDIC - Icelandic (20871 + Euro symbol) |
| 1200 | Unicode UCS-2 Little-Endian (BMP of ISO 10646) |
| 1201 | Unicode UCS-2 Big-Endian |
| 1250 | ANSI - Central European |
| 1251 | ANSI - Cyrillic |
| 1252 | ANSI - Latin I |
| 1253 | ANSI - Greek |
| 1254 | ANSI - Turkish |
| 1255 | ANSI - Hebrew |
| 1256 | ANSI - Arabic |
| 1257 | ANSI - Baltic |
| 1258 | ANSI/OEM - Vietnamese |
| 1361 | Korean (Johab) |
| 10000 | MAC - Roman |
| 10001 | MAC - Japanese |
| 10002 | MAC - Traditional Chinese (Big5) |
| 10003 | MAC - Korean |
| 10004 | MAC - Arabic |
| 10005 | MAC - Hebrew |
| 10006 | MAC - Greek I |
| 10007 | MAC - Cyrillic |
| 10008 | MAC - Simplified Chinese (GB 2312) |
| 10010 | MAC - Romania |
| 10017 | MAC - Ukraine |
| 10021 | MAC - Thai |
| 10029 | MAC - Latin II |
| 10079 | MAC - Icelandic |
| 10081 | MAC - Turkish |
| 10082 | MAC - Croatia |
| 12000 | Unicode UCS-4 Little-Endian |
| 12001 | Unicode UCS-4 Big-Endian |
| 20000 | CNS - Taiwan |
| 20001 | TCA - Taiwan |
| 20002 | Eten - Taiwan |
| 20003 | IBM5550 - Taiwan |
| 20004 | TeleText - Taiwan |
| 20005 | Wang - Taiwan |
| 20105 | IA5 IRV International Alphabet No. 5 (7-bit) |
| 20106 | IA5 German (7-bit) |
| 20107 | IA5 Swedish (7-bit) |
| 20108 | IA5 Norwegian (7-bit) |
| 20127 | US-ASCII (7-bit) |
| 20261 | T.61 |
| 20269 | ISO 6937 Non-Spacing Accent |
| 20273 | IBM EBCDIC - Germany |
| 20277 | IBM EBCDIC - Denmark/Norway |
| 20278 | IBM EBCDIC - Finland/Sweden |
| 20280 | IBM EBCDIC - Italy |
| 20284 | IBM EBCDIC - Latin America/Spain |
| 20285 | IBM EBCDIC - United Kingdom |
| 20290 | IBM EBCDIC - Japanese Katakana Extended |
| 20297 | IBM EBCDIC - France |
| 20420 | IBM EBCDIC - Arabic |
| 20423 | IBM EBCDIC - Greek |
| 20424 | IBM EBCDIC - Hebrew |
| 20833 | IBM EBCDIC - Korean Extended |
| 20838 | IBM EBCDIC - Thai |
| 20866 | Russian - KOI8-R |
| 20871 | IBM EBCDIC - Icelandic |
| 20880 | IBM EBCDIC - Cyrillic (Russian) |
| 20905 | IBM EBCDIC - Turkish |
| 20924 | IBM EBCDIC - Latin-1/Open System (1047 + Euro symbol) |
| 20932 | JIS X 0208-1990 & 0121-1990 |
| 20936 | Simplified Chinese (GB2312) |
| 21025 | IBM EBCDIC - Cyrillic (Serbian, Bulgarian) |
| 21027 | Extended Alpha Lowercase |
| 21866 | Ukrainian (KOI8-U) |
| 28591 | ISO 8859-1 Latin I |
| 28592 | ISO 8859-2 Central Europe |
| 28593 | ISO 8859-3 Latin 3 |
| 28594 | ISO 8859-4 Baltic |
| 28595 | ISO 8859-5 Cyrillic |
| 28596 | ISO 8859-6 Arabic |
| 28597 | ISO 8859-7 Greek |
| 28598 | ISO 8859-8 Hebrew |
| 28599 | ISO 8859-9 Latin 5 |
| 28605 | ISO 8859-15 Latin 9 |
| 29001 | Europa 3 |
| 38598 | ISO 8859-8 Hebrew |
| 50220 | ISO 2022 Japanese with no halfwidth Katakana |
| 50221 | ISO 2022 Japanese with halfwidth Katakana |
| 50222 | ISO 2022 Japanese JIS X 0201-1989 |
| 50225 | ISO 2022 Korean |
| 50227 | ISO 2022 Simplified Chinese |
| 50229 | ISO 2022 Traditional Chinese |
| 50930 | Japanese (Katakana) Extended |
| 50931 | US/Canada and Japanese |
| 50933 | Korean Extended and Korean |
| 50935 | Simplified Chinese Extended and Simplified Chinese |
| 50936 | Simplified Chinese |
| 50937 | US/Canada and Traditional Chinese |
| 50939 | Japanese (Latin) Extended and Japanese |
| 51932 | EUC - Japanese |
| 51936 | EUC - Simplified Chinese |
| 51949 | EUC - Korean |
| 51950 | EUC - Traditional Chinese |
| 52936 | HZ-GB2312 Simplified Chinese |
| 54936 | Windows XP: GB18030 Simplified Chinese (4 Byte) |
| 57002 | ISCII Devanagari |
| 57003 | ISCII Bengali |
| 57004 | ISCII Tamil |
| 57005 | ISCII Telugu |
| 57006 | ISCII Assamese |
| 57007 | ISCII Oriya |
| 57008 | ISCII Kannada |
| 57009 | ISCII Malayalam |
| 57010 | ISCII Gujarati |
| 57011 | ISCII Punjabi |
| 65000 | Unicode UTF-7 |
| 65001 | Unicode UTF-8 |

 The following is a list of valid code page identifiers for Mac OS only:

|  |  |
| --- | --- |
| Identifier | Name |
| 1 | ASCII |
| 2 | NEXTSTEP |
| 3 | JapaneseEUC |
| 4 | UTF8 |
| 5 | ISOLatin1 |
| 6 | Symbol |
| 7 | NonLossyASCII |
| 8 | ShiftJIS |
| 9 | ISOLatin2 |
| 10 | Unicode |
| 11 | WindowsCP1251 |
| 12 | WindowsCP1252 |
| 13 | WindowsCP1253 |
| 14 | WindowsCP1254 |
| 15 | WindowsCP1250 |
| 21 | ISO2022JP |
| 30 | MacOSRoman |
| 10 | UTF16String |
| 0x90000100 | UTF16BigEndian |
| 0x94000100 | UTF16LittleEndian |
| 0x8c000100 | UTF32String |
| 0x98000100 | UTF32BigEndian |
| 0x9c000100 | UTF32LittleEndian |
| 65536 | Proprietary |

**LicenseInfo**: Information about the current license.When queried, this setting will return a string containing information about the license this instance of a component is using. It will return the following information:

- Product: The product the license is for.
- Product Key: The key the license was generated from.
- License Source: Where the license was found (e.g., RuntimeLicense, License File).
- License Type: The type of license installed (e.g., Royalty Free, Single Server).
- Last Valid Build: The last valid build number for which the license will work.

**MaskSensitiveData**: Whether sensitive data is masked in log messages.In certain circumstances it may be beneficial to mask sensitive data, like passwords, in log messages. Set this to *true* to mask sensitive data. The default is *true*.

**UseInternalSecurityAPI**: Whether or not to use the system security libraries or an internal implementation. When set to *false*, the component will use the system security libraries by default to perform cryptographic functions where applicable.

Setting this configuration setting to *true* tells the component to use the internal implementation instead of using the system security libraries.

 This setting is set to *false* by default on all platforms.

# Trappable Errors ([Gzip](#gzip-component) Component)

 **Errors**

The following errors may be generated by the component. Note that frequently the error message will contain more specific information than what is listed here.

Note that some non-fatal errors may be trapped and explicitly ignored in the [Error](#error-event-gzip-component) event. This will allow the component to continue operation even in case of error.

### Gzip Errors

|  |  |
| --- | --- |
| 102 | The gzip archive is of an invalid or unsupported format. |
| 111 | Can't open file for read. |
| 112 | Can't open file for write. |
| 113 | Can't create directory. |
| 114 | The file is too large. |
| 115 | Can't create empty archive. |
| 116 | The archive must be scanned prior to attempting this operation. |
| 117 | The array index is out of range. |
| 118 | The maximum size of the archive has been exceeded. |
| 119 | The archive must be specified, or streaming must be enabled. |
| 120 | The component is busy. |
| 124 | Must specify the compressed name. |
| 127 | Bad CRC-32 checksum. |
| 128 | Unable to set file date. |
| 133 | File already exists in the archive. |
| 150 | An I/O error has occurred (details follow). |