SmartExtract

A Windows-native context menu extension for 7-Zip that extracts archives intelligently — no double-wrapping, no scattered files.

The problem

Standard archive extraction has an annoying inconsistency:

• project.zip containing project/... → extract here → you get project/project/... (double-wrapped)
• files.zip containing loose files → extract here → files scatter into the current folder

You end up either manually moving folders or always extracting to a named subfolder regardless of what's inside.

What SmartExtract does

Right-click any archive and choose Smart Extract. SmartExtract inspects the archive contents first, then chooses the right extraction strategy automatically:

Archive contents	What happens
Single root folder whose name matches the archive	Extracted directly — no double-wrapping
Anything else (loose files, mismatched folder name, multiple entries)	Extracted into a new folder named after the archive

In both cases the result in your working directory is a single, cleanly named folder.

Example

# Archive: my-project.zip
# Contains: my-project/src/, my-project/README.md, ...
# Result: my-project/ appears directly — no my-project/my-project/ nesting

# Archive: release.zip
# Contains: bin/, lib/, README.md (no root folder)
# Result: release/ is created and all contents go inside it

Compound archive extensions are handled correctly: my-project.tar.gz produces a folder named my-project.

Requirements

• Windows — SmartExtract is designed exclusively for the Windows desktop environment. It integrates with the Windows shell context menu and relies on Windows-specific APIs (registry, WinForms message loop, Windows file associations). It will not build or run on Linux or macOS.
• 7-Zip installed (any recent version; 7z.exe and 7zG.exe must be present)
• .NET 10 Runtime (Desktop Runtime)

Supported formats

.zip · .7z · .rar · .gz · .bz2 · .tar

All formats supported by 7-Zip work transparently — SmartExtract delegates the actual extraction to 7zG.exe, so password-protected archives get 7-Zip's native password dialog.

Installation

Option A: Windows Installer (recommended)

Download SmartExtractSetup.exe from the latest release and run it.

The installer wizard will:

1. Let you choose between a machine-wide install (requires administrator) or a per-user install (no admin required)
2. Auto-detect your 7-Zip installation and let you confirm or correct the path
3. Register the Smart Extract context menu entry for all supported extensions

To uninstall, use Settings → Apps or Control Panel → Programs and Features.

Option B: PowerShell scripts (power users / CI)

1. Build

dotnet publish src/SmartExtract/SmartExtract.csproj -c Release -o build/publish/

2. Install (no administrator rights required — per-user install)

PowerShell -ExecutionPolicy Bypass -File scripts/install.ps1
# Optional: specify 7-Zip location explicitly
PowerShell -ExecutionPolicy Bypass -File scripts/install.ps1 -SevenZipDir "C:\Program Files\7-Zip\"

This copies the application to %LOCALAPPDATA%\Programs\SmartExtract\ and registers the Smart Extract context menu entry for all supported extensions under your user account (HKCU).

3. Use

Right-click any supported archive file in Windows Explorer → Smart Extract.

Uninstall

If installed via installer: use Settings → Apps → SmartExtract → Uninstall.

If installed via PowerShell:

PowerShell -ExecutionPolicy Bypass -File scripts/uninstall.ps1

Removes the context menu entries and the install directory. No leftovers.

How it works

SmartExtract is a headless C# WinForms application (WinExe) — it shows no window of its own. When invoked:

1. Inspect — calls 7z.exe l -slt to list archive contents
2. Decide — if there is exactly one top-level directory whose name matches the archive base name (case-insensitive), use Direct mode; otherwise use Wrapped mode
3. Extract — delegates to 7zG.exe (7-Zip's GUI executable), which shows the native 7-Zip progress dialog and handles any password prompts
4. Done — errors are surfaced as a MessageBox; silent on success

7-Zip's path is discovered from SmartExtract's stored configuration (HKCU\Software\SmartExtract\SevenZipPath), then 7-Zip's registry key, PATH, and finally C:\Program Files\7-Zip\.

Project structure

src/SmartExtract/
  Program.cs              Entry point — argument validation and orchestration
  NameHelper.cs           Archive base name extraction (strips .tar.gz etc.)
  ArchiveEntry.cs         Data record: path + directory flag
  ArchiveListParser.cs    Parses 7z.exe -slt output
  SmartExtractLogic.cs    Core Direct/Wrapped decision logic
  SevenZipLocator.cs      Finds 7-Zip installation
  ArchiveInspector.cs     Orchestrates listing and mode decision
  ExtractionRunner.cs     Invokes 7zG.exe

tests/SmartExtract.Tests/
  NameHelperTests.cs
  ArchiveListParserTests.cs
  SmartExtractLogicTests.cs
  SevenZipLocatorTests.cs
  ExtractionRunnerTests.cs

scripts/
  install.ps1             Per-user install + context menu registration
  uninstall.ps1           Cleanup

installer/
  SmartExtract.iss        Inno Setup script (produces dist/SmartExtractSetup.exe)

Building and testing

dotnet build SmartExtract.slnx
dotnet test SmartExtract.slnx -c Release

Note: Windows Smart App Control may block Debug-configuration DLLs from running under dotnet test. Use -c Release for tests.

Tech stack

• C# / .NET 10 (net10.0-windows)
• WinForms (System.Windows.Forms) — for MessageBox only; no window is shown
• Windows Registry (Microsoft.Win32) — for 7-Zip discovery and context menu registration
• xUnit 2.9 — unit tests
• 7-Zip (7z.exe, 7zG.exe) — archive listing and extraction

Architecture

Design decisions and implementation notes are in ARCHITECTURE.md.