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 Building libgit2 - Using CMake
  84 ==============================
  85
  86 `libgit2` builds cleanly on most platforms without any external dependencies.
  87 Under Unix-like systems, like Linux, \*BSD and Mac OS X, libgit2 expects `pthreads` to be available;
  88 they should be installed by default on all systems. Under Windows, libgit2 uses the native Windows API
  89 for threading.
  90
  91 The `libgit2` library is built using [CMake](<http://www.cmake.org>) (version 2.8 or newer) on all platforms.
  92
  93 On most systems you can build the library using the following commands
  94
  95         $ mkdir build && cd build
  96         $ cmake ..
  97         $ cmake --build .
  98
  99 Alternatively you can point the CMake GUI tool to the CMakeLists.txt file and generate platform specific build project or IDE workspace.
 100
 101 To install the library you can specify the install prefix by setting:
 102
 103         $ cmake .. -DCMAKE_INSTALL_PREFIX=/install/prefix
 104         $ cmake --build . --target install
 105
 106 For more advanced use or questions about CMake please read <http://www.cmake.org/Wiki/CMake_FAQ>.
 107
 108 The following CMake variables are declared:
 109
 110 - `BIN_INSTALL_DIR`: Where to install binaries to.
 111 - `LIB_INSTALL_DIR`: Where to install libraries to.
 112 - `INCLUDE_INSTALL_DIR`: Where to install headers to.
 113 - `BUILD_SHARED_LIBS`: Build libgit2 as a Shared Library (defaults to ON)
 114 - `BUILD_CLAR`: Build [Clar](https://github.com/vmg/clar)-based test suite (defaults to ON)
 115 - `THREADSAFE`: Build libgit2 with threading support (defaults to ON)
 116 - `STDCALL`: Build libgit2 as `stdcall`. Turn off for `cdecl` (Windows; defaults to ON)
 117
 118 Compiler and linker options
 119 ---------------------------
 120
 121 CMake lets you specify a few variables to control the behavior of the
 122 compiler and linker. These flags are rarely used but can be useful for
 123 64-bit to 32-bit cross-compilation.
 124
 125 - `CMAKE_C_FLAGS`: Set your own compiler flags
 126 - `CMAKE_FIND_ROOT_PATH`: Override the search path for libraries
 127 - `ZLIB_LIBRARY`, `OPENSSL_SSL_LIBRARY` AND `OPENSSL_CRYPTO_LIBRARY`:
 128 Tell CMake where to find those specific libraries
 129
 130 MacOS X
 131 -------
 132
 133 If you want to build a universal binary for Mac OS X, CMake sets it
 134 all up for you if you use `-DCMAKE_OSX_ARCHITECTURES="i386;x86_64"`
 135 when configuring.
 136
 137 Windows
 138 -------
 139
 140 You need to run the CMake commands from the Visual Studio command
 141 prompt, not the regular or Windows SDK one. Select the right generator
 142 for your version with the `-G "Visual Studio X" option.
 143
 144 See [the website](https://libgit2.github.com/docs/guides/build-and-link)
 145 for more detailed instructions.
 146
 147 Android
 148 -------
 149
 150 Extract toolchain from NDK using, `make-standalone-toolchain.sh` script.
 151 Optionally, crosscompile and install OpenSSL inside of it. Then create CMake
 152 toolchain file that configures paths to your crosscompiler (substitute `{PATH}`
 153 with full path to the toolchain):
 154
 155         SET(CMAKE_SYSTEM_NAME Linux)
 156         SET(CMAKE_SYSTEM_VERSION Android)
 157
 158         SET(CMAKE_C_COMPILER   {PATH}/bin/arm-linux-androideabi-gcc)
 159         SET(CMAKE_CXX_COMPILER {PATH}/bin/arm-linux-androideabi-g++)
 160         SET(CMAKE_FIND_ROOT_PATH {PATH}/sysroot/)
 161
 162         SET(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
 163         SET(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
 164         SET(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
 165
 166 Add `-DCMAKE_TOOLCHAIN_FILE={pathToToolchainFile}` to cmake command
 167 when configuring.
 168
 169 Language Bindings
 170 ==================================
 171
 172 Here are the bindings to libgit2 that are currently available:
 173
 174 * C++
 175     * libqgit2, Qt bindings <https://projects.kde.org/projects/playground/libs/libqgit2/>
 176 * Chicken Scheme
 177     * chicken-git <https://wiki.call-cc.org/egg/git>
 178 * D
 179     * dlibgit <https://github.com/s-ludwig/dlibgit>
 180 * Delphi
 181     * GitForDelphi <https://github.com/libgit2/GitForDelphi>
 182 * Erlang
 183     * Geef <https://github.com/carlosmn/geef>
 184 * Go
 185     * git2go <https://github.com/libgit2/git2go>
 186 * GObject
 187     * libgit2-glib <https://live.gnome.org/Libgit2-glib>
 188 * Haskell
 189     * hgit2 <https://github.com/fpco/gitlib>
 190 * Java
 191     * Jagged <https://github.com/ethomson/jagged>
 192 * Julia
 193     * LibGit2.jl <https://github.com/jakebolewski/LibGit2.jl>
 194 * Lua
 195     * luagit2 <https://github.com/libgit2/luagit2>
 196 * .NET
 197     * libgit2sharp <https://github.com/libgit2/libgit2sharp>
 198 * Node.js
 199     * node-gitteh <https://github.com/libgit2/node-gitteh>
 200     * nodegit <https://github.com/tbranyen/nodegit>
 201 * Objective-C
 202     * objective-git <https://github.com/libgit2/objective-git>
 203 * OCaml
 204     * ocaml-libgit2 <https://github.com/fxfactorial/ocaml-libgit2>
 205 * Parrot Virtual Machine
 206     * parrot-libgit2 <https://github.com/letolabs/parrot-libgit2>
 207 * Perl
 208     * Git-Raw <https://github.com/jacquesg/p5-Git-Raw>
 209 * PHP
 210     * php-git <https://github.com/libgit2/php-git>
 211 * PowerShell
 212     * GitPowerShell <https://github.com/ethomson/gitpowershell>
 213 * Python
 214     * pygit2 <https://github.com/libgit2/pygit2>
 215 * R
 216     * git2r <https://github.com/ropensci/git2r>
 217 * Ruby
 218     * Rugged <https://github.com/libgit2/rugged>
 219 * Rust
 220     * git2-rs <https://github.com/alexcrichton/git2-rs>
 221 * Swift
 222     * Gift <https://github.com/modocache/Gift>
 223 * Vala
 224     * libgit2.vapi <https://github.com/apmasell/vapis/blob/master/libgit2.vapi>
 225
 226 If you start another language binding to libgit2, please let us know so
 227 we can add it to the list.
 228
 229 How Can I Contribute?
 230 ==================================
 231
 232 Check the [contribution guidelines](CONTRIBUTING.md) to understand our
 233 workflow, the libgit2 [coding conventions](CONVENTIONS.md), and our list of
 234 [good starting projects](PROJECTS.md).
 235
 236 License
 237 ==================================
 238
 239 `libgit2` is under GPL2 **with linking exception**. This means you can link to
 240 and use the library from any program, proprietary or open source; paid or
 241 gratis.  However, you cannot modify libgit2 and distribute it without
 242 supplying the source.
 243
 244 See the [COPYING file](COPYING) for the full license text.