README.md

   1 libgit2 - the Git linkable library
   2 ==================================
   3
   4 | Build Status | |
   5 | ------------ | - |
   6 | **master** branch CI builds | [![Azure Pipelines Build Status](https://dev.azure.com/libgit2/libgit2/_apis/build/status/libgit2?branchName=master)](https://dev.azure.com/libgit2/libgit2/_build/latest?definitionId=7&branchName=master)   |
   7 | **v1.0 branch** CI builds | [![Azure Pipelines Build Status](https://dev.azure.com/libgit2/libgit2/_apis/build/status/libgit2?branchName=maint/v1.0)](https://dev.azure.com/libgit2/libgit2/_build/latest?definitionId=7&branchName=maint/v1.0) |
   8 | **v0.28 branch** CI builds | [![Azure Pipelines Build Status](https://dev.azure.com/libgit2/libgit2/_apis/build/status/libgit2?branchName=maint/v0.28)](https://dev.azure.com/libgit2/libgit2/_build/latest?definitionId=7&branchName=maint/v0.28) |
   9 | **Nightly** builds | [![Azure Pipelines Build Status](https://libgit2.visualstudio.com/libgit2/_apis/build/status/nightly?branchName=master&label=Full+Build)](https://libgit2.visualstudio.com/libgit2/_build/latest?definitionId=9&branchName=master) [![Coverity Build Status](https://dev.azure.com/libgit2/libgit2/_apis/build/status/coverity?branchName=master&label=Coverity+Build)](https://dev.azure.com/libgit2/libgit2/_build/latest?definitionId=21?branchName=master) [![Coverity Scan Build Status](https://scan.coverity.com/projects/639/badge.svg)](https://scan.coverity.com/projects/639) |
  10
  11 `libgit2` is a portable, pure C implementation of the Git core methods
  12 provided as a linkable library with a solid API, allowing to build Git
  13 functionality into your application.  Language bindings like
  14 [Rugged](https://github.com/libgit2/rugged) (Ruby),
  15 [LibGit2Sharp](https://github.com/libgit2/libgit2sharp) (.NET),
  16 [pygit2](http://www.pygit2.org/) (Python) and
  17 [NodeGit](http://nodegit.org) (Node) allow you to build Git tooling
  18 in your favorite language.
  19
  20 `libgit2` is used to power Git GUI clients like
  21 [GitKraken](https://gitkraken.com/) and [gmaster](https://gmaster.io/)
  22 and on Git hosting providers like [GitHub](https://github.com/),
  23 [GitLab](https://gitlab.com/) and
  24 [Azure DevOps](https://azure.com/devops).
  25 We perform the merge every time you click "merge pull request".
  26
  27 `libgit2` is licensed under a **very permissive license** (GPLv2 with a special
  28 Linking Exception).  This basically means that you can link it (unmodified)
  29 with any kind of software without having to release its source code.
  30 Additionally, the example code has been released to the public domain (see the
  31 [separate license](examples/COPYING) for more information).
  32
  33 Table of Contents
  34 =================
  35
  36 * [Quick Start](#quick-start)
  37 * [Getting Help](#getting-help)
  38 * [What It Can Do](#what-it-can-do)
  39 * [Optional dependencies](#optional-dependencies)
  40 * [Initialization](#initialization)
  41 * [Threading](#threading)
  42 * [Conventions](#conventions)
  43 * [Building libgit2 - Using CMake](#building-libgit2---using-cmake)
  44     * [Building](#building)
  45     * [Installation](#installation)
  46     * [Advanced Usage](#advanced-usage)
  47     * [Compiler and linker options](#compiler-and-linker-options)
  48     * [MacOS X](#macos-x)
  49     * [Android](#android)
  50     * [MinGW](#mingw)
  51 * [Language Bindings](#language-bindings)
  52 * [How Can I Contribute?](#how-can-i-contribute)
  53 * [License](#license)
  54
  55 Quick Start
  56 ===========
  57
  58 **Prerequisites** for building libgit2:
  59
  60 1. [CMake](https://cmake.org/), and is recommended to be installed into
  61    your `PATH`.
  62 2. [Python](https://www.python.org) is used by our test framework, and
  63    should be installed into your `PATH`.
  64 3. C compiler: libgit2 is C90 and should compile on most compilers.
  65    * Windows: Visual Studio is recommended
  66    * Mac: Xcode is recommended
  67    * Unix: gcc or clang is recommended.
  68
  69 **Build**
  70
  71 1. Create a build directory beneath the libgit2 source directory, and change
  72    into it: `mkdir build && cd build`
  73 2. Create the cmake build environment: `cmake ..`
  74 3. Build libgit2: `cmake --build .`
  75
  76 Trouble with these steps?  Read our [troubleshooting guide](docs/troubleshooting.md).
  77 More detailed build guidance is available below.
  78
  79 Getting Help
  80 ============
  81
  82 **Chat with us**
  83
  84 - via IRC: join [#libgit2](https://webchat.freenode.net/#libgit2) on Freenode
  85 - via Slack: visit [slack.libgit2.org](http://slack.libgit2.org/) to sign up,
  86   then join us in `#libgit2`
  87
  88 **Getting Help**
  89
  90 If you have questions about the library, please be sure to check out the
  91 [API documentation](http://libgit2.github.com/libgit2/).  If you still have
  92 questions, reach out to us on Slack or post a question on
  93 [StackOverflow](http://stackoverflow.com/questions/tagged/libgit2) (with the `libgit2` tag).
  94
  95 **Reporting Bugs**
  96
  97 Please open a [GitHub Issue](https://github.com/libgit2/libgit2/issues) and
  98 include as much information as possible.  If possible, provide sample code
  99 that illustrates the problem you're seeing.  If you're seeing a bug only
 100 on a specific repository, please provide a link to it if possible.
 101
 102 We ask that you not open a GitHub Issue for help, only for bug reports.
 103
 104 **Reporting Security Issues**
 105
 106 Please have a look at SECURITY.md.
 107
 108 What It Can Do
 109 ==============
 110
 111 libgit2 provides you with the ability to manage Git repositories in the
 112 programming language of your choice.  It's used in production to power many
 113 applications including GitHub.com, Plastic SCM and Azure DevOps.
 114
 115 It does not aim to replace the git tool or its user-facing commands. Some APIs
 116 resemble the plumbing commands as those align closely with the concepts of the
 117 Git system, but most commands a user would type are out of scope for this
 118 library to implement directly.
 119
 120 The library provides:
 121
 122 * SHA conversions, formatting and shortening
 123 * abstracted ODB backend system
 124 * commit, tag, tree and blob parsing, editing, and write-back
 125 * tree traversal
 126 * revision walking
 127 * index file (staging area) manipulation
 128 * reference management (including packed references)
 129 * config file management
 130 * high level repository management
 131 * thread safety and reentrancy
 132 * descriptive and detailed error messages
 133 * ...and more (over 175 different API calls)
 134
 135 As libgit2 is purely a consumer of the Git system, we have to
 136 adjust to changes made upstream. This has two major consequences:
 137
 138 * Some changes may require us to change provided interfaces. While we try to
 139   implement functions in a generic way so that no future changes are required,
 140   we cannot promise a completely stable API.
 141 * As we have to keep up with changes in behavior made upstream, we may lag
 142   behind in some areas. We usually to document these incompatibilities in our
 143   issue tracker with the label "git change".
 144
 145 Optional dependencies
 146 =====================
 147
 148 While the library provides git functionality without the need for
 149 dependencies, it can make use of a few libraries to add to it:
 150
 151 - pthreads (non-Windows) to enable threadsafe access as well as multi-threaded pack generation
 152 - OpenSSL (non-Windows) to talk over HTTPS and provide the SHA-1 functions
 153 - LibSSH2 to enable the SSH transport
 154 - iconv (OSX) to handle the HFS+ path encoding peculiarities
 155
 156 Initialization
 157 ===============
 158
 159 The library needs to keep track of some global state. Call
 160
 161     git_libgit2_init();
 162
 163 before calling any other libgit2 functions. You can call this function many times. A matching number of calls to
 164
 165     git_libgit2_shutdown();
 166
 167 will free the resources.  Note that if you have worker threads, you should
 168 call `git_libgit2_shutdown` *after* those threads have exited.  If you
 169 require assistance coordinating this, simply have the worker threads call
 170 `git_libgit2_init` at startup and `git_libgit2_shutdown` at shutdown.
 171
 172 Threading
 173 =========
 174
 175 See [threading](docs/threading.md) for information
 176
 177 Conventions
 178 ===========
 179
 180 See [conventions](docs/conventions.md) for an overview of the external
 181 and internal API/coding conventions we use.
 182
 183 Building libgit2 - Using CMake
 184 ==============================
 185
 186 Building
 187 --------
 188
 189 `libgit2` builds cleanly on most platforms without any external dependencies.
 190 Under Unix-like systems, like Linux, \*BSD and Mac OS X, libgit2 expects `pthreads` to be available;
 191 they should be installed by default on all systems. Under Windows, libgit2 uses the native Windows API
 192 for threading.
 193
 194 The `libgit2` library is built using [CMake](<https://cmake.org/>) (version 2.8 or newer) on all platforms.
 195
 196 On most systems you can build the library using the following commands
 197
 198         $ mkdir build && cd build
 199         $ cmake ..
 200         $ cmake --build .
 201
 202 Alternatively you can point the CMake GUI tool to the CMakeLists.txt file and generate platform specific build project or IDE workspace.
 203
 204 Running Tests
 205 -------------
 206
 207 Once built, you can run the tests from the `build` directory with the command
 208
 209         $ ctest -V
 210
 211 Alternatively you can run the test suite directly using,
 212
 213         $ ./libgit2_clar
 214
 215 Invoking the test suite directly is useful because it allows you to execute
 216 individual tests, or groups of tests using the `-s` flag.  For example, to
 217 run the index tests:
 218
 219     $ ./libgit2_clar -sindex
 220
 221 To run a single test named `index::racy::diff`, which corresponds to the test
 222 function [`test_index_racy__diff`](https://github.com/libgit2/libgit2/blob/master/tests/index/racy.c#L23):
 223
 224     $ ./libgit2_clar -sindex::racy::diff
 225
 226 The test suite will print a `.` for every passing test, and an `F` for any
 227 failing test.  An `S` indicates that a test was skipped because it is not
 228 applicable to your platform or is particularly expensive.
 229
 230 **Note:** There should be _no_ failing tests when you build an unmodified
 231 source tree from a [release](https://github.com/libgit2/libgit2/releases),
 232 or from the [master branch](https://github.com/libgit2/libgit2/tree/master).
 233 Please contact us or [open an issue](https://github.com/libgit2/libgit2/issues)
 234 if you see test failures.
 235
 236 Installation
 237 ------------
 238
 239 To install the library you can specify the install prefix by setting:
 240
 241         $ cmake .. -DCMAKE_INSTALL_PREFIX=/install/prefix
 242         $ cmake --build . --target install
 243
 244 Advanced Usage
 245 --------------
 246
 247 For more advanced use or questions about CMake please read <https://cmake.org/Wiki/CMake_FAQ>.
 248
 249 The following CMake variables are declared:
 250
 251 - `CMAKE_INSTALL_BINDIR`: Where to install binaries to.
 252 - `CMAKE_INSTALL_LIBDIR`: Where to install libraries to.
 253 - `CMAKE_INSTALL_INCLUDEDIR`: Where to install headers to.
 254 - `BUILD_SHARED_LIBS`: Build libgit2 as a Shared Library (defaults to ON)
 255 - `BUILD_CLAR`: Build [Clar](https://github.com/vmg/clar)-based test suite (defaults to ON)
 256 - `THREADSAFE`: Build libgit2 with threading support (defaults to ON)
 257
 258 To list all build options and their current value, you can do the
 259 following:
 260
 261         # Create and set up a build directory
 262         $ mkdir build
 263         $ cmake ..
 264         # List all build options and their values
 265         $ cmake -L
 266
 267 Compiler and linker options
 268 ---------------------------
 269
 270 CMake lets you specify a few variables to control the behavior of the
 271 compiler and linker. These flags are rarely used but can be useful for
 272 64-bit to 32-bit cross-compilation.
 273
 274 - `CMAKE_C_FLAGS`: Set your own compiler flags
 275 - `CMAKE_FIND_ROOT_PATH`: Override the search path for libraries
 276 - `ZLIB_LIBRARY`, `OPENSSL_SSL_LIBRARY` AND `OPENSSL_CRYPTO_LIBRARY`:
 277 Tell CMake where to find those specific libraries
 278
 279 MacOS X
 280 -------
 281
 282 If you want to build a universal binary for Mac OS X, CMake sets it
 283 all up for you if you use `-DCMAKE_OSX_ARCHITECTURES="i386;x86_64"`
 284 when configuring.
 285
 286 Android
 287 -------
 288
 289 Extract toolchain from NDK using, `make-standalone-toolchain.sh` script.
 290 Optionally, crosscompile and install OpenSSL inside of it. Then create CMake
 291 toolchain file that configures paths to your crosscompiler (substitute `{PATH}`
 292 with full path to the toolchain):
 293
 294         SET(CMAKE_SYSTEM_NAME Linux)
 295         SET(CMAKE_SYSTEM_VERSION Android)
 296
 297         SET(CMAKE_C_COMPILER   {PATH}/bin/arm-linux-androideabi-gcc)
 298         SET(CMAKE_CXX_COMPILER {PATH}/bin/arm-linux-androideabi-g++)
 299         SET(CMAKE_FIND_ROOT_PATH {PATH}/sysroot/)
 300
 301         SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
 302         SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
 303         SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
 304
 305 Add `-DCMAKE_TOOLCHAIN_FILE={pathToToolchainFile}` to cmake command
 306 when configuring.
 307
 308 MinGW
 309 -----
 310
 311 If you want to build the library in MinGW environment with SSH support enabled,
 312 you may need to pass `-DCMAKE_LIBRARY_PATH="${MINGW_PREFIX}/${MINGW_CHOST}/lib/"` flag
 313 to CMake when configuring. This is because CMake cannot find the Win32 libraries in
 314 MinGW folders by default and you might see an error message stating that CMake
 315 could not resolve `ws2_32` library during configuration.
 316
 317 Another option would be to install `msys2-w32api-runtime` package before configuring.
 318 This package installs the Win32 libraries into `/usr/lib` folder which is by default
 319 recognized as the library path by CMake. Please note though that this package is meant
 320 for MSYS subsystem which is different from MinGW.
 321
 322 Language Bindings
 323 ==================================
 324
 325 Here are the bindings to libgit2 that are currently available:
 326
 327 * C++
 328     * libqgit2, Qt bindings <https://projects.kde.org/projects/playground/libs/libqgit2/repository/>
 329 * Chicken Scheme
 330     * chicken-git <https://wiki.call-cc.org/egg/git>
 331 * D
 332     * dlibgit <https://github.com/s-ludwig/dlibgit>
 333 * Delphi
 334     * GitForDelphi <https://github.com/libgit2/GitForDelphi>
 335 * Erlang
 336     * Geef <https://github.com/carlosmn/geef>
 337 * Go
 338     * git2go <https://github.com/libgit2/git2go>
 339 * GObject
 340     * libgit2-glib <https://wiki.gnome.org/Projects/Libgit2-glib>
 341 * Guile
 342         * Guile-Git <https://gitlab.com/guile-git/guile-git>
 343 * Haskell
 344     * hgit2 <https://github.com/jwiegley/gitlib>
 345 * Java
 346     * Jagged <https://github.com/ethomson/jagged>
 347 * Javascript / WebAssembly ( browser and nodejs )
 348     * WASM-git <https://github.com/petersalomonsen/wasm-git>
 349 * Julia
 350     * LibGit2.jl <https://github.com/JuliaLang/julia/tree/master/stdlib/LibGit2>
 351 * Lua
 352     * luagit2 <https://github.com/libgit2/luagit2>
 353 * .NET
 354     * libgit2sharp <https://github.com/libgit2/libgit2sharp>
 355 * Node.js
 356     * nodegit <https://github.com/nodegit/nodegit>
 357 * Objective-C
 358     * objective-git <https://github.com/libgit2/objective-git>
 359 * OCaml
 360     * ocaml-libgit2 <https://github.com/fxfactorial/ocaml-libgit2>
 361 * Parrot Virtual Machine
 362     * parrot-libgit2 <https://github.com/letolabs/parrot-libgit2>
 363 * Perl
 364     * Git-Raw <https://github.com/jacquesg/p5-Git-Raw>
 365 * PHP
 366     * php-git <https://github.com/libgit2/php-git>
 367 * PowerShell
 368     * PSGit <https://github.com/PoshCode/PSGit>
 369 * Python
 370     * pygit2 <https://github.com/libgit2/pygit2>
 371 * R
 372     * git2r <https://github.com/ropensci/git2r>
 373 * Ruby
 374     * Rugged <https://github.com/libgit2/rugged>
 375 * Rust
 376     * git2-rs <https://github.com/rust-lang/git2-rs>
 377 * Swift
 378     * SwiftGit2 <https://github.com/SwiftGit2/SwiftGit2>
 379 * Vala
 380     * libgit2.vapi <https://github.com/apmasell/vapis/blob/master/libgit2.vapi>
 381
 382 If you start another language binding to libgit2, please let us know so
 383 we can add it to the list.
 384
 385 How Can I Contribute?
 386 ==================================
 387
 388 We welcome new contributors!  We have a number of issues marked as
 389 ["up for grabs"](https://github.com/libgit2/libgit2/issues?q=is%3Aissue+is%3Aopen+label%3A%22up+for+grabs%22)
 390 and
 391 ["easy fix"](https://github.com/libgit2/libgit2/issues?utf8=✓&q=is%3Aissue+is%3Aopen+label%3A%22easy+fix%22)
 392 that are good places to jump in and get started.  There's much more detailed
 393 information in our list of [outstanding projects](docs/projects.md).
 394
 395 Please be sure to check the [contribution guidelines](docs/contributing.md) to
 396 understand our workflow, and the libgit2 [coding conventions](docs/conventions.md).
 397
 398 License
 399 ==================================
 400
 401 `libgit2` is under GPL2 **with linking exception**. This means you can link to
 402 and use the library from any program, proprietary or open source; paid or
 403 gratis.  However, if you modify libgit2 itself, you must distribute the
 404 source to your modified version of libgit2.
 405
 406 See the [COPYING file](COPYING) for the full license text.