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libgit2 is a portable, pure C implementation of the Git core methodsprovided as a linkable library with a solid API, allowing to build Gitfunctionality into your application.

libgit2 is used in a variety of places, from GUI clients to hostingproviders ("forges") and countless utilities and applications inbetween. Because it's written in C, it can be made available to anyother programming language through "bindings", so you can use it inRuby,.NET,Python,Node.js,Rust, and more.

libgit2 is licensed under avery permissive license (GPLv2 witha special Linking Exception). This means that you can link againstthe library with any kind of software without making that softwarefall under the GPL. Changes to libgit2 would still be covered underits GPL license.

• Using libgit2
• Quick Start
• Getting Help
• What It Can Do
• Optional dependencies
• Initialization
• Threading
• Conventions
• Building libgit2 - Using CMake
  • Building
  • Installation
  • Advanced Usage
  • Compiler and linker options
  • macOS
  • iOS
  • Android
  • MinGW
• Language Bindings
• How Can I Contribute?
• License

Most of these instructions assume that you're writing an applicationin C and want to use libgit2 directly. If you'renot using C,and you're writing in a different language or platform like .NET,Node.js, or Ruby, then there is probably a"language binding" that you can use to take careof the messy tasks of calling into native code.

But if youdo want to use libgit2 directly - because you're buildingan application in C - then you may be able use an existing binary.There are packages for thevcpkg andconanpackage managers. And libgit2 is available inHomebrew and most Linuxdistributions.

However, these versionsmay be outdated and we recommend using thelatest version if possible. Thankfully libgit2 is not hard to compile.

Prerequisites for building libgit2:

1. CMake, and is recommended to be installed intoyourPATH.
2. Python is used by our test framework, andshould be installed into yourPATH.
3. C compiler: libgit2 is C90 and should compile on most compilers.
   • Windows: Visual Studio is recommended
   • Mac: Xcode is recommended
   • Unix: gcc or clang is recommended.

Build

1. Create a build directory beneath the libgit2 source directory,and change into it:mkdir build && cd build
2. Create the cmake build environment:cmake ..
3. Build libgit2:cmake --build .

Trouble with these steps? Read ourtroubleshooting guide.More detailed build guidance is available below.

Chat with us

• via IRC: join#libgit2 onlibera.
• via Slack: visitslack.libgit2.orgto sign up, then join us in#libgit2

Getting Help

If you have questions about the library, please be sure to check out theAPI documentation. If you still havequestions, reach out to us on Slack or post a question onStackOverflow(with thelibgit2 tag).

Reporting Bugs

Please open aGitHub Issueand include as much information as possible. If possible, providesample code that illustrates the problem you're seeing. If you'reseeing a bug only on a specific repository, please provide a link toit if possible.

We ask that you not open a GitHub Issue for help, only for bug reports.

Reporting Security Issues

Please have a look at SECURITY.md.

libgit2 provides you with the ability to manage Git repositories in theprogramming language of your choice. It's used in production to power manyapplications including GitHub.com, Plastic SCM and Azure DevOps.

It does not aim to replace the git tool or its user-facing commands. SomeAPIs resemble the plumbing commands as those align closely with theconcepts of the Git system, but most commands a user would type are outof scope for this library to implement directly.

The library provides:

• SHA conversions, formatting and shortening
• abstracted ODB backend system
• commit, tag, tree and blob parsing, editing, and write-back
• tree traversal
• revision walking
• index file (staging area) manipulation
• reference management (including packed references)
• config file management
• high level repository management
• thread safety and reentrancy
• descriptive and detailed error messages
• ...and more (over 175 different API calls)

As libgit2 is purely a consumer of the Git system, we have toadjust to changes made upstream. This has two major consequences:

• Some changes may require us to change provided interfaces. Whilewe try to implement functions in a generic way so that no futurechanges are required, we cannot promise a completely stable API.
• As we have to keep up with changes in behavior made upstream, wemay lag behind in some areas. We usually to document theseincompatibilities in our issue tracker with the label "git change".

While the library provides git functionality with very fewdependencies, some recommended dependencies are used for performanceor complete functionality.

• Hash generation: Git uses SHA1DC (collision detecting SHA1) forits default hash generation. SHA256 support is experimental, andoptimized support is provided by system libraries on macOS andWindows, or by the HTTPS library on Unix systems when available.
• Threading: is provided by the system libraries on Windows, andpthreads on Unix systems.
• HTTPS: is provided by the system libraries on macOS and Windows,or by OpenSSL or mbedTLS on other Unix systems.
• SSH: is provided bylibssh2 or by invokingOpenSSH.
• Unicode: is provided by the system libraries on Windows and macOS.

The library needs to keep track of some global state. Call

git_libgit2_init();

before calling any other libgit2 functions. You can call this function many times. A matching number of calls to

git_libgit2_shutdown();

will free the resources. Note that if you have worker threads, you shouldcallgit_libgit2_shutdownafter those threads have exited. If yourequire assistance coordinating this, simply have the worker threads callgit_libgit2_init at startup andgit_libgit2_shutdown at shutdown.

Seethreading for information

Seeconventions for an overview of the externaland internal API/coding conventions we use.

libgit2 builds cleanly on most platforms without any externaldependencies as a requirement.libgit2 is built usingCMake (version 2.8 or newer) on all platforms.

On most systems you can build the library using the following commands

$ mkdir build && cd build$ cmake ..$ cmake --build .

To include the examples in the build, usecmake -DBUILD_EXAMPLES=ON ..instead ofcmake ... The built executable for the examples can thenbe found inbuild/examples, relative to the toplevel directory.

Alternatively you can point the CMake GUI tool to the CMakeLists.txt file and generate platform specific build project or IDE workspace.

If you're not familiar with CMake,a more detailed explanation may be helpful.

You can specify a number of options tocmake that will change thewaylibgit2 is built. To use this, specify-Doption=value duringthe initialcmake configuration. For example, to enable SHA256compatibility:

$ mkdir build && cd build$ cmake -DEXPERIMENTAL_SHA256=ON ..$ cmake --build .

libgit2 options:

• EXPERIMENTAL_SHA256=ON: turns on SHA256 compatibility; note thatthis is an API-incompatible change, hence why it is labeled"experimental"

Build options:

• BUILD_EXAMPLES=ON: builds the suite of example code
• BUILD_FUZZERS=ON: builds the fuzzing suite
• ENABLE_WERROR=ON: build with-Werror or the equivalent, which turnscompiler warnings into errors in the libgit2 codebase (but not itsdependencies)

Dependency options:

• USE_SSH=type: enables SSH support and optionally selects the provider;type can be set tolibssh2 orexec (which will execute an externalOpenSSH command).ON implieslibssh2; defaults toOFF.
• USE_HTTPS=type: enables HTTPS support and optionally selects theprovider;type can be set toOpenSSL,OpenSSL-Dynamic (to notlink against OpenSSL, but load it dynamically),SecureTransport,Schannel orWinHTTP; the default isSecureTransport on macOS,WinHTTP on Windows, and whichever ofOpenSSL ormbedTLS isdetected on other platforms. Defaults toON.
• USE_SHA1=type: selects the SHA1 mechanism to use;type can be settoCollisionDetection,HTTPS to use the system or HTTPS provider,or one ofOpenSSL,OpenSSL-Dynamic,OpenSSL-FIPS (to use FIPScompliant routines in OpenSSL),CommonCrypto, orSchannel.Defaults toCollisionDetection. This option is retained forbackward compatibility and should not be changed.
• USE_SHA256=type: selects the SHA256 mechanism to use;type can beset toHTTPS to use the system or HTTPS driver,builtin, or one ofOpenSSL,OpenSSL-Dynamic,OpenSSL-FIPS (to use FIPS compliantroutines in OpenSSL),CommonCrypto, orSchannel. Defaults toHTTPS.
• USE_GSSAPI=<on/off>: enables GSSAPI for SPNEGO authentication onUnix. Defaults toOFF.
• USE_HTTP_PARSER=type: selects the HTTP Parser; eitherhttp-parserfor an externalhttp-parser dependency,llhttp for an externalllhttpdependency, orbuiltin. Defaults tobuiltin.
• REGEX_BACKEND=type: selects the regular expression backend to use;one ofregcomp_l,pcre2,pcre,regcomp, orbuiltin. Thedefault is to useregcomp_l where available, PCRE if found, otherwise,to use the builtin.
• USE_BUNDLED_ZLIB=type: selects the bundled zlib; eitherON orOFF.Defaults to using the system zlib if available, falling back to thebundled zlib.

Thelibgit2 project usescmake since it helps with cross-platformprojects, especially those with many dependencies. If your dependenciesare in non-standard places, you may want to use the_ROOT_DIR optionsto specify their location. For example, to specify an OpenSSL location:

$ cmake -DOPENSSL_ROOT_DIR=/tmp/openssl-3.3.2 ..

Since these options are general to CMake, theirdocumentation may be helpful. Ifyou have questions about dependencies, pleasecontact us.

Once built, you can run the tests from thebuild directory with the command

$ ctest -V

Alternatively you can run the test suite directly using,

$ ./libgit2_tests

Invoking the test suite directly is useful because it allows you to executeindividual tests, or groups of tests using the-s flag. For example, torun the index tests:

$ ./libgit2_tests -sindex

To run a single test namedindex::racy::diff, which corresponds tothe test functiontest_index_racy__diff:

$ ./libgit2_tests -sindex::racy::diff

The test suite will print a. for every passing test, and anF for anyfailing test. AnS indicates that a test was skipped because it is notapplicable to your platform or is particularly expensive.

Note: There should beno failing tests when you build an unmodifiedsource tree from arelease,or from themain branch.Please contact us oropen an issueif you see test failures.

To install the library you can specify the install prefix by setting:

$ cmake .. -DCMAKE_INSTALL_PREFIX=/install/prefix$ cmake --build . --target install

For more advanced use or questions about CMake please read theCMake FAQ.

The following CMake variables are declared:

• CMAKE_INSTALL_BINDIR: Where to install binaries to.
• CMAKE_INSTALL_LIBDIR: Where to install libraries to.
• CMAKE_INSTALL_INCLUDEDIR: Where to install headers to.
• BUILD_SHARED_LIBS: Build libgit2 as a Shared Library (defaults to ON)
• BUILD_TESTS: Build the unit and integration test suites (defaults to ON)
• USE_THREADS: Build libgit2 with threading support (defaults to ON)

To list all build options and their current value, you can do thefollowing:

# Create and set up a build directory$ mkdir build && cd build$ cmake ..# List all build options and their values$ cmake -L

There are several options that control the behavior of the compiler andlinker. These flags may be useful for cross-compilation or specializedsetups.

• CMAKE_C_FLAGS: Set your own compiler flags
• CMAKE_C_STANDARD: the C standard to compile against; defaults toC90
• CMAKE_C_EXTENSIONS: whether compiler extensions are supported; defaults toOFF
• CMAKE_FIND_ROOT_PATH: Override the search path for libraries
• ZLIB_LIBRARY,OPENSSL_SSL_LIBRARY ANDOPENSSL_CRYPTO_LIBRARY:Tell CMake where to find those specific libraries
• LINK_WITH_STATIC_LIBRARIES: Link only with static versions ofsystem libraries

If you'd like to work with Xcode, you can generate an Xcode project with "-G Xcode".

# Create and set up a build directory$ mkdir build && cd build$ cmake -G Xcode ..

1. Get an iOS cmake toolchain File:

You can use a pre-existing toolchain file likeios-cmake or write your own.

2. Specify the toolchain and system Name:

• The CMAKE_TOOLCHAIN_FILE variable points to the toolchain file for iOS.
• The CMAKE_SYSTEM_NAME should be set to iOS.

3. Example Command:

Assuming you're using the ios-cmake toolchain, the command might look like this:

cmake -G Xcode -DCMAKE_TOOLCHAIN_FILE=path/to/ios.toolchain.cmake -DCMAKE_SYSTEM_NAME=iOS -DPLATFORM=OS64 ..

4. Build the Project:

After generating the project, open the .xcodeproj file in Xcode, select your iOS device or simulator as the target, and build your project.

Extract toolchain from NDK using,make-standalone-toolchain.sh script.Optionally, crosscompile and install OpenSSL inside of it. Then create CMaketoolchain file that configures paths to your crosscompiler (substitute{PATH}with full path to the toolchain):

SET(CMAKE_SYSTEM_NAME Linux)SET(CMAKE_SYSTEM_VERSION Android)SET(CMAKE_C_COMPILER   {PATH}/bin/arm-linux-androideabi-gcc)SET(CMAKE_CXX_COMPILER {PATH}/bin/arm-linux-androideabi-g++)SET(CMAKE_FIND_ROOT_PATH {PATH}/sysroot/)SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)

Add-DCMAKE_TOOLCHAIN_FILE={pathToToolchainFile} to cmake commandwhen configuring.

If you want to build the library in MinGW environment with SSH supportenabled, you may need to pass-DCMAKE_LIBRARY_PATH="${MINGW_PREFIX}/${MINGW_CHOST}/lib/" flagto CMake when configuring. This is because CMake cannot find theWin32 libraries in MinGW folders by default and you might see anerror message stating that CMake could not resolvews2_32 libraryduring configuration.

Another option would be to installmsys2-w32api-runtime package beforeconfiguring. This package installs the Win32 libraries into/usr/libfolder which is by default recognized as the library path by CMake.Please note though that this package is meant for MSYS subsystem whichis different from MinGW.

Here are the bindings to libgit2 that are currently available:

• C++
  • libqgit2, Qt bindingshttps://projects.kde.org/projects/playground/libs/libqgit2/repository/
• Chicken Scheme
  • chicken-githttps://wiki.call-cc.org/egg/git
• D
  • dlibgithttps://github.com/s-ludwig/dlibgit
• Delphi
  • GitForDelphihttps://github.com/libgit2/GitForDelphi
  • libgit2-delphihttps://github.com/todaysoftware/libgit2-delphi
• Erlang
  • Geefhttps://github.com/carlosmn/geef
• Go
  • git2gohttps://github.com/libgit2/git2go
• GObject
  • libgit2-glibhttps://wiki.gnome.org/Projects/Libgit2-glib
• Guile
  • Guile-Githttps://gitlab.com/guile-git/guile-git
• Haskell
  • hgit2https://github.com/jwiegley/gitlib
• Java
  • Jaggedhttps://github.com/ethomson/jagged
  • Git24jhttps://github.com/git24j/git24j
• Javascript / WebAssembly ( browser and nodejs )
  • WASM-githttps://github.com/petersalomonsen/wasm-git
• Julia
  • LibGit2.jlhttps://github.com/JuliaLang/julia/tree/master/stdlib/LibGit2
• Lua
  • luagit2https://github.com/libgit2/luagit2
• .NET
  • libgit2sharphttps://github.com/libgit2/libgit2sharp
• Node.js
  • nodegithttps://github.com/nodegit/nodegit
• Objective-C
  • objective-githttps://github.com/libgit2/objective-git
• OCaml
  • ocaml-libgit2https://github.com/fxfactorial/ocaml-libgit2
• Parrot Virtual Machine
  • parrot-libgit2https://github.com/letolabs/parrot-libgit2
• Perl
  • Git-Rawhttps://github.com/jacquesg/p5-Git-Raw
• Pharo Smalltalk
  • libgit2-pharo-bindingshttps://github.com/pharo-vcs/libgit2-pharo-bindings
• PHP
  • php-git2https://github.com/RogerGee/php-git2
• Python
  • pygit2https://github.com/libgit2/pygit2
• R
  • gerthttps://docs.ropensci.org/gert
  • git2rhttps://github.com/ropensci/git2r
• Ruby
  • Ruggedhttps://github.com/libgit2/rugged
• Rust
  • git2-rshttps://github.com/rust-lang/git2-rs
• Swift
  • SwiftGit2https://github.com/SwiftGit2/SwiftGit2
• Tcl
  • lg2https://github.com/apnadkarni/tcl-libgit2
• Vala
  • libgit2.vapihttps://github.com/apmasell/vapis/blob/master/libgit2.vapi

If you start another language binding to libgit2, please let us know sowe can add it to the list.

We welcome new contributors! We have a number of issues marked as"up for grabs"and"easy fix"that are good places to jump in and get started. There's much more detailedinformation in our list ofoutstanding projects.

Please be sure to check thecontribution guidelinesto understand our workflow, and the libgit2coding conventions.

libgit2 is under GPL2with linking exception. This means you canlink to and use the library from any program, proprietary or open source;paid or gratis. However, if you modify libgit2 itself, you must distributethe source to your modified version of libgit2.

See theCOPYING file for the full license text.