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Overview

7-Zip is a file archiver developed and maintained by Igor Pavlov. The project is open source and distributed under the GNU LGPL license (with some exceptions for specific components). 7-Zip Copyright (C) 1999-2026 Igor Pavlov.

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Source Code Repository

The 7-Zip source code is organized into several main directories:
  • DOC - Documentation files
  • Asm - Optimized assembler code for CRC, SHA, AES, and LZMA decoding
  • C - Source code in C
  • CPP - Source code in C++
    • Common - Common files for C++ projects
    • Windows - Windows-specific code
    • 7zip - Core 7-Zip modules

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Compilation Instructions

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Compiling on Windows

To compile 7-Zip on Windows, you need Visual Studio or Windows SDK.
Supported Platforms:
  • x86 (Visual C++ 6.0 with Platform SDK or VS 2017/2019/2022)
  • x64 (Windows Server 2003 R2 Platform SDK or VS 2017/2019/2022)
  • arm64 (VS 2017/2019/2022)
  • arm (VS 2017/2019/2022)
  • ia64 (Windows Server 2003 R2 Platform SDK)
Required Tools:
  • Microsoft Macro Assembler (ml.exe for x86, ml64.exe for x64)
Compile Options:
  1. Via makefile (recommended for production):
cd SRC\CPP\7zip
%comspec% /k "C:\Program Files\VS2022\VC\Auxiliary\Build\vcvars64.bat"
nmake
  1. Via DSP file in Visual Studio (for development/debugging)
Makefile Macros:
  • PLATFORM - x64, x86, arm64, arm, ia64
  • OLD_COMPILER - for old VC compilers like MSVC 6.0
  • MY_DYNAMIC_LINK - for dynamic linking to msvcrt.dll

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Compiling on Linux/macOS

7-Zip can be compiled on Unix-like systems using GCC or Clang.
Assembler Support:For optimal performance, you can compile with assembler code:Basic Compilation:
cd CPP/7zip/Bundles/Alone2
make -j -f makefile.gcc
Optimized Compilation:
# GCC without assembler
make -j -f ../../cmpl_gcc.mak

# Clang without assembler
make -j -f ../../cmpl_clang.mak

# GCC x86-64 with assembler
make -j -f ../../cmpl_gcc_x64.mak

# GCC arm64 with assembler
make -j -f ../../cmpl_gcc_arm64.mak

# macOS arm64
make -j -f ../../cmpl_mac_arm64.mak
Makefile Variables:
  • USE_JWASM=1 - Use JWasm instead of Asmc (note: JWasm doesn’t support AES instructions)
  • DISABLE_RAR=1 - Remove all RAR-related code
  • DISABLE_RAR_COMPRESS=1 - Remove RAR decompression codecs (keeps archive listing/stored file extraction)
Using UASM:
UASM="$PWD/GccUnixR/uasm"
cd "7zip-src/CPP/7zip/Bundles/Alone2"
make -f makefile.gcc -j IS_X64=1 USE_ASM=1 MY_ASM="$UASM"

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Build Targets

The 7-Zip source can be compiled into various binaries:
TargetDescription
7za.exeStandalone console version (7z/xz/cab/zip/gzip/bzip2/tar)
7zz.exeStandalone console version (all formats)
7zr.exeStandalone console version (7z only, reduced)
7z.exeConsole version
7zFM.exe7-Zip File Manager
7zG.exe7-Zip GUI version
7z.dllDLL supporting all formats
7za.dllDLL for .7z support
7-zip.dll7-Zip Shell extension
lzma.exeLZMA compression/decompression

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Development Guidelines

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Code Organization

7-Zip uses a modular COM-based architecture (though it doesn’t use standard COM interfaces):
  • 7zip/Common - Common modules
  • 7zip/Archive - Archive format handlers
  • 7zip/Compress - Compression/decompression algorithms
  • 7zip/Crypto - Encryption/decryption
  • 7zip/UI - User interface components
  • 7zip/Bundle - Standalone module bundles

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Using 7-Zip DLLs

See the 7zip/UI/Client7z folder for examples of using 7-Zip DLL files.
Some DLL files may depend on other 7-Zip DLLs. For standalone DLLs without dependencies, use bundle versions like 7zip/Bundles/Format7z.

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RAR Support Compilation Options

RAR decompression codecs have additional license restrictions that may not be fully compatible with free-software licenses.
When compiling, you can control RAR support:
  • Full RAR support (default) - Includes all RAR decompression capabilities
  • DISABLE_RAR_COMPRESS=1 - Removes “not fully free” RAR decompression codecs. 7-Zip can still:
    • Open RAR archives
    • List files
    • Extract stored (uncompressed) files
  • DISABLE_RAR=1 - Completely removes RAR support

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LZMA SDK

The 7-Zip source package includes files from LZMA SDK, which is written and placed in the public domain by Igor Pavlov. LZMA SDK is available separately at: http://www.7-zip.org/sdk.html

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7-Zip vs p7zip

There are two different ports of 7-Zip for Linux/macOS:
  1. p7zip - Independent port (latest version 16.02, now outdated)
  2. 7-Zip for Linux/macOS - Official port with all changes from latest Windows version
    • Recommended for new projects
These ports are not identical. Some Linux-specific features may be better implemented in p7zip.

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Additional Resources

  • 7zC.txt - 7z ANSI-C Decoder description
  • 7zFormat.txt - 7z format specification
  • Methods.txt - Compression method IDs
  • lzma.txt - LZMA compression description
  • src-history.txt - Source code change history

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Contact

Igor Pavlov
http://www.7-zip.org

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