1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
CommonMark
==========
CommonMark is a rationalized version of Markdown syntax,
with a [spec][the spec] and BSD-licensed reference
implementations in C and JavaScript.
[Try it now!](http://spec.commonmark.org/dingus.html)
For more information, see <http://commonmark.org>.
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
[the spec]: http://spec.commonmark.org
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
|
