Archives #

Archives are files that act as containers for other files and folders. The C# standard library allows working with archives in .zip and .tar (from .NET 7) formats through classes in the System.IO.Compression namespace.

ZIP Archives #

ZIP archives, in addition to grouping files, also offer data compression by default.

For simple operations, the static ZipFile class is used, which allows for quick creation of an archive from a folder (CreateFromDirectory) or extracting it (ExtractToDirectory).

const string sourceDirectory = "my_files_to_zip";
const string zipPath = "archive.zip";
const string extractPath = "extracted_files";

Directory.CreateDirectory(sourceDirectory);
File.WriteAllText(Path.Combine(sourceDirectory, "file1.txt"), "Hello");
Directory.CreateDirectory(Path.Combine(sourceDirectory, "subfolder"));
File.WriteAllText(Path.Combine(sourceDirectory, "subfolder", "file2.txt"), "World");

// Creating .zip archive (override existing)
if (File.Exists(zipPath)) File.Delete(zipPath);
ZipFile.CreateFromDirectory(sourceDirectory, zipPath);

// Extracting archive (override if files exist)
if (Directory.Exists(extractPath)) Directory.Delete(extractPath, true);
ZipFile.ExtractToDirectory(zipPath, extractPath);

For more advanced operations, the ZipFile.Open method is used, which returns a ZipArchive object. This allows for precise manipulation of archive contents entry by entry. An archive can be opened in one of three modes: Read, Create, or Update.

using ZipArchive zip = ZipFile.Open("archive.zip", ZipArchiveMode.Read);

Console.WriteLine("Archive content:");
foreach (ZipArchiveEntry entry in zip.Entries)
{
    Console.WriteLine($"{entry.FullName,-32} Size: {entry.Length} bytes");
}

The table below presents selected methods and properties that allow for precise manipulation of archives after opening them.

Method or Property	Description
`ZipArchive.Entries`	Retrieves a collection of all entries (files and folders) within the archive.
`ZipArchive.CreateEntry`	Creates a new, empty entry in the archive.
`ZipArchive.GetEntry`	Retrieves a specific entry from the archive based on its name.
`ZipArchive.CreateEntryFromFile`	(Extension method) Creates a new entry in the archive based on an existing file on disk.
`ZipArchive.ExtractToDirectory`	(Extension method) Extracts the entire contents of the archive to a specified folder.
`ZipArchiveEntry.Delete`	Deletes the current entry from the archive.
`ZipArchiveEntry.Open`	Opens a stream to the entry’s content, allowing it to be read or written.
`ZipArchiveEntry.ExtractToFile`	(Extension method) Extracts the current entry to a file on disk.

TAR Archives (.NET 7) #

The TAR (Tape Archive) format only groups files into a single container, but does not apply compression itself. Its advantage is support for Unix system attributes. In practice, .tar archives are often additionally compressed using GZip, Brotli, or BZip2 (not available in the standard library) algorithms, resulting in files with .tar.gz (or .tgz) and .tar.br extensions.

Similar to ZIP, the TarFile class provides easy-to-use CreateFromDirectory and ExtractToDirectory methods.

const string sourceDirectory = "my_files_to_tar";
const string tarPath = "archive.tar";

Directory.CreateDirectory(sourceDirectory);
File.WriteAllText(Path.Combine(sourceDirectory, "log.txt"), "Log entry");

// Creating .tar archive
if (File.Exists(tarPath)) File.Delete(tarPath);
TarFile.CreateFromDirectory(sourceDirectory, tarPath);

Similarly, the ExtractToDirectory method is used to extract archives. Unlike ZipFile, it requires the target folder to exist.

const string tarPath = "archive.tar";
const string extractPath = "extracted_tar_files";

// Extracting .tar archive
if (Directory.Exists(extractPath)) Directory.Delete(extractPath, true);
Directory.CreateDirectory(extractPath);
TarFile.ExtractToDirectory(tarPath, extractPath, false);

To create a compressed .tar.gz archive, instead of providing a path, provide a stream with applied compression when creating the archive:

// Creating .tar.gz archive
using FileStream fileStream = new("archive.tar.gz", FileMode.Create);
using GZipStream gzipStream = new(fileStream, CompressionMode.Compress);
TarFile.CreateFromDirectory(sourceDirectory, gzipStream, false);

To extract a compressed archive (e.g., .tar.gz), use the appropriate decompression stream.

const string sourceArchive = "archive.tar.gz";
const string destinationDirectory = "extracted_targz_files";

if (Directory.Exists(destinationDirectory)) Directory.Delete(destinationDirectory, true);
Directory.CreateDirectory(destinationDirectory);

// Extracting .tar.gz archive
using FileStream fileStream = File.OpenRead(sourceArchive);
using GZipStream gzipStream = new(fileStream, CompressionMode.Decompress);
TarFile.ExtractToDirectory(gzipStream, destinationDirectory, false);