Listing the contents of a tar archive

This topic demonstrates how to get a listing of all of the files contained in a GZipped Tar archive, that is, a Tar archive that has been compressed using GZip. Note: Tar and FileSystem-based GZip are not currently available in Xceed's .NET Compact Framework products.

Basic steps

To list the contents of a gzipped Tar archive, the following steps must be performed:

Retrieve a reference to an AbstractFile-derived class, such as the DiskFile, MemoryFile or IsolatedFile class, using the name of the GZipped Tar archive.
Retrieve a reference to a GZip archive using the GZippedFile class, passing the AbstractFile-based object retrieved in the previous step to its constructor. Note: To create a non-GZipped Tar archive, omit this step.
Retrieve a reference to a Tar archive using the TarArchive class, passing the GZippedFile retrieved in the previous step to its constructor (or the DiskFile object from the first step for a non-GZipped Tar archive).
You can now loop through the files and extract the desired information.

When performing many operations on an archive, you may wish to consider optimizing your code by using batch updates.

Using a non-GZipped Tar archive may be preferable in some situations: for example, when read/write speed is essential but storage space is unlimited, when you need to access individual files in the Tar archive without uncompressing the entire archive, or when the files inside the Tar archive are already compressed.

Setting the LicenseKey property with Tar also unlocks the GZip capabilities.

Demonstration

This example demonstrates how to list the contents of a GZipped Tar archive.

VB.NET Copy Code

VB.NET	Copy Code
`Imports Xceed.Tar Imports Xceed.GZip Imports Xceed.FileSystem` `Dim diskFile As New DiskFile("c:\test.tar.gz") Dim gzip As New GZippedFile(diskFile) Dim tar As New TarArchive(gzip)` `Dim f As AbstractFile` `For Each f In tar.GetFiles( True ) ListBox1.Items.Add( f.FullName ) Next`

Imports Xceed.Tar Imports Xceed.GZip Imports Xceed.FileSystem

Dim diskFile As New DiskFile("c:\test.tar.gz") Dim gzip As New GZippedFile(diskFile) Dim tar As New TarArchive(gzip)

Dim f As AbstractFile

For Each f In tar.GetFiles( True ) ListBox1.Items.Add( f.FullName ) Next

C# Copy Code

C#	Copy Code
`using Xceed.Tar; using Xceed.GZip; using Xceed.FileSystem;` `DiskFile diskFile = new DiskFile(@"E:\test.tar.gz"); GZippedFile gzip = new GZippedFile(diskFile); TarArchive tar = new TarArchive(gzip);` `foreach (AbstractFile file in tar.GetFiles(true)) { Console.WriteLine("File {0} is {1} bytes", file.FullName, file.Size); }`

using Xceed.Tar; using Xceed.GZip; using Xceed.FileSystem;

DiskFile diskFile = new DiskFile(@"E:\test.tar.gz"); GZippedFile gzip = new GZippedFile(diskFile); TarArchive tar = new TarArchive(gzip);

foreach (AbstractFile file in tar.GetFiles(true)) { Console.WriteLine("File {0} is {1} bytes", file.FullName, file.Size); }

Things you should consider

The main questions you should ask yourself when listing the contents of a Tar file are:

Do you want to filter (specify specific files and folders) the items that are to be listed? Use filters.
Do you also want to retrieve a listing of the Tarred folders? Use the GetFolders method.
Do you want to retrieve a reference to a single Tarred file or folder? Use the GetFile or GetFolder methods.
Do you want to display the status of the operation? See the Events topic.
Do you want to list the contents of a specific folder within the Tar archive? Create an instance of a TarredFolder object rather than a TarArchive object.