CommonMark ========== CommonMark is a rationalized version of Markdown syntax, with a [spec][the spec] and BSD3-licensed reference implementations in C and JavaScript. [Try it now!](http://spec.commonmark.org/dingus.html) For more information, see . This repository contains the C reference implementation. It provides a shared library (`libcmark`) with functions for parsing CommonMark documents to an abstract syntax tree (AST), manipulating the AST, and rendering the document to HTML or to an XML representation of the AST. It also provides a command-line program (`cmark`) for parsing and rendering CommonMark documents. The library and program are written in standard C99 and have no library dependencies. The parser is very fast, on par with [sundown]: see the [benchmarks]. It is easy to use `libcmark` in python, lua, ruby, and other dynamic languages: see the `wrappers/` subdirectory for some simple examples. [sundown]: https://github.com/vmg/sundown [benchmarks]: benchmarks.md Installing ---------- Building the C program (`cmark`) and shared library (`libcmark`) requires [cmake]. If you modify `scanners.re`, then you will also need [re2c], which is used to generate `scanners.c` from `scanners.re`. We have included a pre-generated `scanners.c` in the repository to reduce build dependencies. If you have GNU make, you can simply `make`, `make test`, and `make install`. This calls [cmake] to create a `Makefile` in the `build` directory, then uses that `Makefile` to create the executable and library. The binaries can be found in `build/src`. The default installation prefix is `/usr/local`. To change the installation prefix, pass the `INSTALL_PREFIX` variable if you run `make` for the first time: `make INSTALL_PREFIX=path`. For a more portable method, you can use [cmake] manually. [cmake] knows how to create build environments for many build systems. For example, on FreeBSD: mkdir build cd build cmake .. # optionally: -DCMAKE_INSTALL_PREFIX=path make # executable will be created as build/src/cmark make test make install Or, to create Xcode project files on OSX: mkdir build cd build cmake -G Xcode .. open cmark.xcodeproj The GNU Makefile also provides a few other targets for developers. To run a benchmark: make bench To run a "fuzz test" against ten long randomly generated inputs: make fuzztest To run a test for memory leaks using `valgrind`: make leakcheck To reformat source code using `astyle`: make astyle To make a release tarball and zip archive: make archive Installing (Windows) -------------------- To compile with MSVC and NMAKE: nmake You can cross-compile a Windows binary and dll on linux if you have the `mingw32` compiler: make mingw The binaries will be in `build-mingw/windows/bin`. Usage ----- Instructions for the use of the command line program and library can be found in the man pages in the `man` subdirectory. **A note on security:** This library does not attempt to sanitize link attributes or raw HTML. If you use it in applications that accept untrusted user input, you must run the output through an HTML sanitizer to protect against [XSS attacks](http://en.wikipedia.org/wiki/Cross-site_scripting). Contributing ------------ There is a [forum for discussing CommonMark](http://talk.commonmark.org); you should use it instead of github issues for questions and possibly open-ended discussions. Use the [github issue tracker](http://github.com/jgm/CommonMark/issues) only for simple, clear, actionable issues. Authors ------- John MacFarlane wrote the original library and program. The block parsing algorithm was worked out together with David Greenspan. Vicent Marti optimized the C implementation for performance, increasing its speed tenfold. Kārlis Gaņģis helped work out a better parsing algorithm for links and emphasis, eliminating several worst-case performance issues. Nick Wellnhofer contributed many improvements, including most of the C library's API and its test harness. [cmake]: http://www.cmake.org/download/ [re2c]: http://re2c.org