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