Nsis7z NSIS Plugin

NSIS plugin for extracting 7z, ZIP and NSIS archives.

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Available Versions

Version	7-Zip	Formats	Notes
19.00	7-Zip 19.00	7z, LZMA, XZ, Split	Original updated version
25.01	7-Zip 25.01	7z, ZIP, LZMA, XZ, Split, NSIS	With NSIS archive support
26.00	7-Zip 26.00	7z, ZIP, LZMA, XZ, Split, NSIS	Recommended

Supported Architectures

Architecture	Description
x86-ansi	32-bit ANSI (legacy)
x86-unicode	32-bit Unicode
amd64-unicode	64-bit Unicode

Quick Start

!addplugindir "plugins\x86-unicode"

Section
  ; Simple extraction (7z, ZIP, NSIS)
  Nsis7z::Extract "$EXEDIR\data.7z"

  ; With progress text in label
  Nsis7z::ExtractWithDetails "$EXEDIR\data.7z" "Installing %s..."

  ; With callback to show files in listbox
  GetFunctionAddress $0 MyExtractCallback
  Nsis7z::ExtractWithFileCallback "$EXEDIR\data.7z" $0
SectionEnd

Function MyExtractCallback
  Pop $0   ; completedSize
  Pop $1   ; totalSize
  Pop $2   ; fileName
  DetailPrint "$2"
FunctionEnd

Build Scripts

The repo includes a single unified build_plugin.py script that replaces the previous per-version scripts.

Build

# Recommended: 7-Zip 26.00 with auto-detected toolset
python build_plugin.py

# Select 7-Zip version (19.00 | 25.01 | 26.00)
python build_plugin.py --7zip-version 25.01

# Specific toolset (2022|2026|auto)
python build_plugin.py --toolset 2022

# Linux host path (cross-build with MinGW-w64, 26.00)
python build_plugin.py --host linux

# Print version and exit
python build_plugin.py --version

Linux notes:

• Local Linux path currently supports --7zip-version 26.00.
• Requires MinGW-w64 toolchains (x86_64-w64-mingw32-* and i686-w64-mingw32-*) and make.

Repository Structure

nsis-plugin-ns7zip/
├── build_plugin.py              # Unified build script (all versions)
├── build_zstd.cmd               # Build script for 7-zip-zstd variant
├── rebuild_nsis7z1900-src.ps1   # Rebuilds 19.00 sources
├── versions/
│   ├── 19.00/                   # 7-Zip 19.00 modified
│   ├── 25.01/                   # 7-Zip 25.01 modified (ZIP + NSIS handler)
│   ├── 26.00/                   # 7-Zip 26.00 modified (ZIP + NSIS handler)
│   └── 7-zip-zstd/              # 7-Zip zstd fork (submodule)
├── plugins/                     # Compiled DLLs output
├── tools/
│   ├── fix_vcxproj.py           # Project file patcher
│   ├── update_gitea_releases.py # Backfill Gitea release bodies (one-shot)
│   ├── release-notes/           # Per-version Markdown snippets
│   ├── linux/                   # Linux-specific build helpers
│   └── legacy/                  # Old per-version build scripts
└── .github/workflows/
    ├── build.yml                # CI: Windows + Linux matrix build
    └── release.yml              # Release: build artifacts + publish to GitHub & Gitea

CI / Release Workflow

• build.yml — runs on every push/PR; builds all three configs on Windows (MSBuild) and Linux (MinGW-w64) in parallel.
• release.yml — triggered by a v* tag push; builds and packages artifacts, creates a GitHub Release with the relevant CHANGELOG section as body, and updates the corresponding Gitea release body via API (GITEA_TOKEN secret required).

Changes from Original

NSIS Archive Handler (25.01, 26.00)

Added support for extracting .exe archives created with NSIS (not present in the original plugin):

• Archive\Nsis\NsisHandler.cpp/h
• Archive\Nsis\NsisIn.cpp/h
• Archive\Nsis\NsisDecode.cpp/h
• Archive\Nsis\NsisRegister.cpp
• Compress\BZip2Decoder.cpp/h (required by NsisDecode)
• Compress\BZip2Crc.cpp

Bug Fixes (25.01, 26.00)

• Divide-by-zero: added guard if (totalSize == 0) return 0 in GetPercentComplete
• ExtractWithFileCallback: NSIS callback triggered only on filename change (avoids crash with totalSize = UINT64_MAX on first SetTotal call)

License

• 7-Zip: LGPL 2.1 + BSD 3-clause
• NSIS Plugin: Afrow UK

Credits

• Igor Pavlov (7-Zip)
• Afrow UK (Original plugin)
• Simone (x64 support, VS2022/VS2026, ZIP, NSIS handler, ExtractWithFileCallback)

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See README_IT.md for the Italian version.