SharpSevenZip

A managed C# wrapper around the native 7-Zip library. SharpSevenZip drives 7z.dll through its COM interface and adds an LZMA SDK implementation and self-extracting archive support on top.

Resource	Link
Source code	github.com/JeremyAnsel/SharpSevenZip
Documentation	jeremyansel.github.io/SharpSevenZip
NuGet	SharpSevenZip
NuGet (strong-named)	SharpSevenZip.StrongName
Build	AppVeyor
License	LGPL-3.0-or-later

Installation

dotnet add package SharpSevenZip

Target frameworks are net8.0, net48 and netstandard2.0. The package ships the x86 and x64 builds of 7z.dll and copies them into the corresponding subfolders of the output directory; set the MSBuild property ExcludeSevenZipAssemblies to true to suppress that.

Quick start

The library exposes three main types:

Type	Purpose
SharpSevenZipExtractor	Extracts archives, single entries or LZMA-compressed byte arrays
SharpSevenZipCompressor	Creates and updates archives from files, directories or streams
SharpSevenZipSfx	Builds self-extracting archives

LzmaEncodeStream and LzmaDecodeStream are fully managed Stream implementations for raw LZMA data and need no native library.

Extracting

using SharpSevenZip;

using var extractor = new SharpSevenZipExtractor(@"C:\archive.7z");

foreach (var entry in extractor.ArchiveFileData)
{
    Console.WriteLine($"{entry.FileName} ({entry.Size} bytes)");
}

extractor.ExtractArchive(@"C:\output");

The input format is detected from the archive signature, so every format in InArchiveFormat — 7z, zip, rar, cab, iso and many more — can be read. Extraction from SFX archives and other formats with embedded archives is supported as well.

Compressing

using SharpSevenZip;

var compressor = new SharpSevenZipCompressor
{
    ArchiveFormat = OutArchiveFormat.SevenZip,
    CompressionLevel = CompressionLevel.High
};

compressor.CompressDirectory(@"C:\input", @"C:\archive.7z");

Output is limited to the formats 7-Zip can write: SevenZip, Zip, Tar, GZip, BZip2 and XZ. GZip and BZip2 compress a single file at a time.

Native library

A native 7-Zip library is required at runtime. By default SharpSevenZip loads <directory of SharpSevenZip.dll>\x86\7z.dll or …\x64\7z.dll, matching the process architecture.

Another location can be configured in app.config or at runtime:

SharpSevenZipBase.SetLibraryPath(@"C:\Program Files\7-Zip\7z.dll");

7z.dll covers all archive operations. 7za.dll is a smaller variant restricted to 7z archives, and a custom build of the 7-Zip sources containing only the formats you need works too.

Features

• All 7-Zip archive formats for reading, all writable formats for compression
• Encryption, passwords and encrypted headers
• Archive properties, archive updates and multi-volume archives
• Streaming, multi-threading, configurable compression level and method
• Self-extracting archives

Self-extracting archives

SharpSevenZipSfx uses the SFX module by Oleg Scherbakov, which is embedded in the assembly.

Alternative modules are available in SharpSevenZip/sfx. Combined with SfxSettings scenarios this can produce small installers; the available directives are listed under "configuration file parameters" of the SFX module.

Custom compression switches

SharpSevenZipCompressor.CustomParameters accepts the switches of the 7z.exe command line, for example to enable multi-threaded compression:

compressor.CustomParameters.Add("mt", "on");

The complete list of switches is documented in 7-zip.chm and SevenZipDoc.chm of a 7-Zip installation.

Strong naming

Two packages are published from the same sources:

Package	Assembly identity
SharpSevenZip	not strong-named
SharpSevenZip.StrongName	strong-named, public key token 7b9e68449741c4c5

Use SharpSevenZip.StrongName when your own application or library is strong-named and therefore requires strong-named references. Both packages contain an assembly named SharpSevenZip, so a project can reference only one of them.

The key pair used for signing, SharpSevenZip/SharpSevenZip/SharpSevenZip.snk, is part of the repository. Anyone can build an assembly with that identity; strong naming provides an identity, not a security guarantee.

Benchmarks

Decompression compared against System.IO.Compression, SharpCompress and SevenZipSharp. Empty decompresses an empty archive, Sum1 a small payload; the stream variants read from a Stream instead of a file.

Scenario	Library	Mean (net48)	Alloc (net48)	Mean (net8.0)	Alloc (net8.0)
Empty	System.IO.Compression	1.077 ms	56 KB	2.990 ms	51.3 KB
Empty	SharpCompress	2.902 ms	152 KB	7.448 ms	131.8 KB
Empty	SevenZipSharp	7.412 ms	1440.1 KB	14.186 ms	1437.2 KB
Empty	SharpSevenZip	2.238 ms	72 KB	7.723 ms	83.7 KB
Sum1	System.IO.Compression	5.875 ms	64 KB	8.799 ms	59.8 KB
Sum1	SharpCompress	5.156 ms	824.7 KB	9.976 ms	797.8 KB
Sum1	SharpCompress (stream)	8.936 ms	816.7 KB	12.757 ms	797.0 KB
Sum1	SevenZipSharp	24.214 ms	28333.2 KB	32.895 ms	28359.7 KB
Sum1	SharpSevenZip	9.725 ms	112 KB	19.595 ms	123.6 KB
Sum1	SharpSevenZip (stream)	34.122 ms	171.6 KB	18.431 ms	129.2 KB

The benchmark project is SharpSevenZipBenchmarks.

History

SharpSevenZip is a fork of Squid-Box.SevenZipSharp, which forked tomap's fork of the original CodePlex project by Markovtsev Vadim.

As required by the license, the notable changes since the CodePlex project, including those made in tomap's fork, are:

• Target frameworks moved from .NET Framework 2.0 to .NET Standard 2.0, .NET Framework 4.8 and .NET 8.0.
• Continuous integration added for both building and publishing.
• Tests rewritten as NUnit 3 test cases.
• General code cleanup, along with a number of improvements and bug fixes.

License

Licensed under the GNU Lesser General Public License v3.0 or later.