README.md

   1 libgit2 - the Git linkable library
   2 ==================================
   3
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   7
   8 `libgit2` is a portable, pure C implementation of the Git core methods
   9 provided as a re-entrant linkable library with a solid API, allowing you to
  10 write native speed custom Git applications in any language with bindings.
  11
  12 `libgit2` is licensed under a **very permissive license** (GPLv2 with a special
  13 Linking Exception).  This basically means that you can link it (unmodified)
  14 with any kind of software without having to release its source code.
  15 Additionally, the example code has been released to the public domain (see the
  16 [separate license](examples/COPYING) for more information).
  17
  18 Getting Help
  19 ============
  20
  21 **Join us on Slack**
  22
  23 Visit [slack.libgit2.org](http://slack.libgit2.org/) to sign up, then join
  24 us in `#libgit2`.  If you prefer IRC, you can also point your client to our
  25 slack channel once you've registered.
  26
  27 **Getting Help**
  28
  29 If you have questions about the library, please be sure to check out the
  30 [API documentation](http://libgit2.github.com/libgit2/).  If you still have
  31 questions, reach out to us on Slack or post a question on
  32 [StackOverflow](http://stackoverflow.com/questions/tagged/libgit2) (with the `libgit2` tag).
  33
  34 **Reporting Bugs**
  35
  36 Please open a [GitHub Issue](https://github.com/libgit2/libgit2/issues) and
  37 include as much information as possible.  If possible, provide sample code
  38 that illustrates the problem you're seeing.  If you're seeing a bug only
  39 on a specific repository, please provide a link to it if possible.
  40
  41 We ask that you not open a GitHub Issue for help, only for bug reports.
  42
  43 What It Can Do
  44 ==============
  45
  46 `libgit2` is already very usable and is being used in production for many
  47 applications including the GitHub.com site, in Plastic SCM and also powering
  48 Microsoft's Visual Studio tools for Git.  The library provides:
  49
  50 * SHA conversions, formatting and shortening
  51 * abstracted ODB backend system
  52 * commit, tag, tree and blob parsing, editing, and write-back
  53 * tree traversal
  54 * revision walking
  55 * index file (staging area) manipulation
  56 * reference management (including packed references)
  57 * config file management
  58 * high level repository management
  59 * thread safety and reentrancy
  60 * descriptive and detailed error messages
  61 * ...and more (over 175 different API calls)
  62
  63 Optional dependencies
  64 =====================
  65
  66 While the library provides git functionality without the need for
  67 dependencies, it can make use of a few libraries to add to it:
  68
  69 - pthreads (non-Windows) to enable threadsafe access as well as multi-threaded pack generation
  70 - OpenSSL (non-Windows) to talk over HTTPS and provide the SHA-1 functions
  71 - LibSSH2 to enable the SSH transport
  72 - iconv (OSX) to handle the HFS+ path encoding peculiarities
  73
  74 Initialization
  75 ===============
  76
  77 The library needs to keep track of some global state. Call
  78
  79     git_libgit2_init();
  80
  81 before calling any other libgit2 functions. You can call this function many times. A matching number of calls to
  82
  83     git_libgit2_shutdown();
  84
  85 will free the resources.  Note that if you have worker threads, you should
  86 call `git_libgit2_shutdown` *after* those threads have exited.  If you
  87 require assistance coordinating this, simply have the worker threads call
  88 `git_libgit2_init` at startup and `git_libgit2_shutdown` at shutdown.
  89
  90 Threading
  91 =========
  92
  93 See [THREADING](THREADING.md) for information
  94
  95 Conventions
  96 ===========
  97
  98 See [CONVENTIONS](CONVENTIONS.md) for an overview of the external
  99 and internal API/coding conventions we use.
 100
 101 Building libgit2 - Using CMake
 102 ==============================
 103
 104 `libgit2` builds cleanly on most platforms without any external dependencies.
 105 Under Unix-like systems, like Linux, \*BSD and Mac OS X, libgit2 expects `pthreads` to be available;
 106 they should be installed by default on all systems. Under Windows, libgit2 uses the native Windows API
 107 for threading.
 108
 109 The `libgit2` library is built using [CMake](<https://cmake.org/>) (version 2.8 or newer) on all platforms.
 110
 111 On most systems you can build the library using the following commands
 112
 113         $ mkdir build && cd build
 114         $ cmake ..
 115         $ cmake --build .
 116
 117 Alternatively you can point the CMake GUI tool to the CMakeLists.txt file and generate platform specific build project or IDE workspace.
 118
 119 To install the library you can specify the install prefix by setting:
 120
 121         $ cmake .. -DCMAKE_INSTALL_PREFIX=/install/prefix
 122         $ cmake --build . --target install
 123
 124 For more advanced use or questions about CMake please read <https://cmake.org/Wiki/CMake_FAQ>.
 125
 126 The following CMake variables are declared:
 127
 128 - `BIN_INSTALL_DIR`: Where to install binaries to.
 129 - `LIB_INSTALL_DIR`: Where to install libraries to.
 130 - `INCLUDE_INSTALL_DIR`: Where to install headers to.
 131 - `BUILD_SHARED_LIBS`: Build libgit2 as a Shared Library (defaults to ON)
 132 - `BUILD_CLAR`: Build [Clar](https://github.com/vmg/clar)-based test suite (defaults to ON)
 133 - `THREADSAFE`: Build libgit2 with threading support (defaults to ON)
 134 - `STDCALL`: Build libgit2 as `stdcall`. Turn off for `cdecl` (Windows; defaults to ON)
 135
 136 Compiler and linker options
 137 ---------------------------
 138
 139 CMake lets you specify a few variables to control the behavior of the
 140 compiler and linker. These flags are rarely used but can be useful for
 141 64-bit to 32-bit cross-compilation.
 142
 143 - `CMAKE_C_FLAGS`: Set your own compiler flags
 144 - `CMAKE_FIND_ROOT_PATH`: Override the search path for libraries
 145 - `ZLIB_LIBRARY`, `OPENSSL_SSL_LIBRARY` AND `OPENSSL_CRYPTO_LIBRARY`:
 146 Tell CMake where to find those specific libraries
 147
 148 MacOS X
 149 -------
 150
 151 If you want to build a universal binary for Mac OS X, CMake sets it
 152 all up for you if you use `-DCMAKE_OSX_ARCHITECTURES="i386;x86_64"`
 153 when configuring.
 154
 155 Windows
 156 -------
 157
 158 You need to run the CMake commands from the Visual Studio command
 159 prompt, not the regular or Windows SDK one. Select the right generator
 160 for your version with the `-G "Visual Studio X" option.
 161
 162 See [the website](http://libgit2.github.com/docs/guides/build-and-link/)
 163 for more detailed instructions.
 164
 165 Android
 166 -------
 167
 168 Extract toolchain from NDK using, `make-standalone-toolchain.sh` script.
 169 Optionally, crosscompile and install OpenSSL inside of it. Then create CMake
 170 toolchain file that configures paths to your crosscompiler (substitute `{PATH}`
 171 with full path to the toolchain):
 172
 173         SET(CMAKE_SYSTEM_NAME Linux)
 174         SET(CMAKE_SYSTEM_VERSION Android)
 175
 176         SET(CMAKE_C_COMPILER   {PATH}/bin/arm-linux-androideabi-gcc)
 177         SET(CMAKE_CXX_COMPILER {PATH}/bin/arm-linux-androideabi-g++)
 178         SET(CMAKE_FIND_ROOT_PATH {PATH}/sysroot/)
 179
 180         SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
 181         SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
 182         SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
 183
 184 Add `-DCMAKE_TOOLCHAIN_FILE={pathToToolchainFile}` to cmake command
 185 when configuring.
 186
 187 Language Bindings
 188 ==================================
 189
 190 Here are the bindings to libgit2 that are currently available:
 191
 192 * C++
 193     * libqgit2, Qt bindings <https://projects.kde.org/projects/playground/libs/libqgit2/>
 194 * Chicken Scheme
 195     * chicken-git <https://wiki.call-cc.org/egg/git>
 196 * D
 197     * dlibgit <https://github.com/s-ludwig/dlibgit>
 198 * Delphi
 199     * GitForDelphi <https://github.com/libgit2/GitForDelphi>
 200 * Erlang
 201     * Geef <https://github.com/carlosmn/geef>
 202 * Go
 203     * git2go <https://github.com/libgit2/git2go>
 204 * GObject
 205     * libgit2-glib <https://wiki.gnome.org/Projects/Libgit2-glib>
 206 * Haskell
 207     * hgit2 <https://github.com/jwiegley/gitlib>
 208 * Java
 209     * Jagged <https://github.com/ethomson/jagged>
 210 * Julia
 211     * LibGit2.jl <https://github.com/jakebolewski/LibGit2.jl>
 212 * Lua
 213     * luagit2 <https://github.com/libgit2/luagit2>
 214 * .NET
 215     * libgit2sharp <https://github.com/libgit2/libgit2sharp>
 216 * Node.js
 217     * nodegit <https://github.com/nodegit/nodegit>
 218 * Objective-C
 219     * objective-git <https://github.com/libgit2/objective-git>
 220 * OCaml
 221     * ocaml-libgit2 <https://github.com/fxfactorial/ocaml-libgit2>
 222 * Parrot Virtual Machine
 223     * parrot-libgit2 <https://github.com/letolabs/parrot-libgit2>
 224 * Perl
 225     * Git-Raw <https://github.com/jacquesg/p5-Git-Raw>
 226 * PHP
 227     * php-git <https://github.com/libgit2/php-git>
 228 * PowerShell
 229     * PSGit <https://github.com/PoshCode/PSGit>
 230 * Python
 231     * pygit2 <https://github.com/libgit2/pygit2>
 232 * R
 233     * git2r <https://github.com/ropensci/git2r>
 234 * Ruby
 235     * Rugged <https://github.com/libgit2/rugged>
 236 * Rust
 237     * git2-rs <https://github.com/alexcrichton/git2-rs>
 238 * Swift
 239     * Gift <https://github.com/modocache/Gift>
 240 * Vala
 241     * libgit2.vapi <https://github.com/apmasell/vapis/blob/master/libgit2.vapi>
 242
 243 If you start another language binding to libgit2, please let us know so
 244 we can add it to the list.
 245
 246 How Can I Contribute?
 247 ==================================
 248
 249 We welcome new contributors!  We have a number of issues marked as
 250 ["up for grabs"](https://github.com/libgit2/libgit2/issues?q=is%3Aissue+is%3Aopen+label%3A%22up+for+grabs%22)
 251 and
 252 ["easy fix"](https://github.com/libgit2/libgit2/issues?utf8=✓&q=is%3Aissue+is%3Aopen+label%3A%22easy+fix%22)
 253 that are good places to jump in and get started.  There's much more detailed
 254 information in our list of [outstanding projects](PROJECTS.md).
 255
 256 Please be sure to check the [contribution guidelines](CONTRIBUTING.md) to
 257 understand our workflow, and the libgit2 [coding conventions](CONVENTIONS.md).
 258
 259 License
 260 ==================================
 261
 262 `libgit2` is under GPL2 **with linking exception**. This means you can link to
 263 and use the library from any program, proprietary or open source; paid or
 264 gratis.  However, if you modify libgit2 itself, you must distribute the
 265 source to your modified version of libgit2.
 266
 267 See the [COPYING file](COPYING) for the full license text.