blog/wtmp/barf/posts/markdown-examples.md

# Markdown Examples in barf

2023-01-05

This following was lifted from [https://github.com/karlb/smu](https://github.com/karlb/smu)

`smu` Syntax
============

smu was started as a rewrite of
[markdown](http://daringfireball.net/projects/markdown/) but became something
more lightweight and consistent. It differs from [CommonMark](https://commonmark.org/) in the following ways:

* No support for _reference style links_
* Stricter indentation rules for lists
* Lists don't end paragraphs by themselves (blank line needed)
* Horizontal rules (`<hr>`) must use `- - -` as syntax
* Code fences have stricter syntax

Patches that increase the CommonMark compatibility are welcome as long as they don't increase the code complexity significantly.

This project is a fork of the [original smu](https://github.com/gottox/smu) by
[Enno Boland (gottox)](https://eboland.de). The main differences to the
original smu are:

* Support for code fences
* Improved [CommonMark](https://commonmark.org/) compatibility. E.g.
  * Code blocks need four spaces indentation instead of three
  * Skip empty lines at end of code blocks
  * Ignore single spaces around code spans
  * Keep HTML comments in output
  * Improved spec compliance for lists
  * Nesting code block in blockquotes works
  * "Empty" lines in lists behave identically, no matter how much whitespace they contain
  * No backslash escapes in code blocks
  * Use first number as start number for ordered lists
* Added a simple test suite to check for compliance and avoid regressions

Inline patterns
---------------

There are several patterns you can use to highlight your text:

* Emphasis
  * Surround your text with `*` or `_` to get *emphasised* text:
    	This *is* cool.
    	This _is_ cool, too.
  * Surround your text with `**` or `__` to get **strong** text:
    	This **is** cool.
    	This __is__ cool, too.
  * Surround your text with `***` or `___` to get ***strong and emphasised*** text:
    	This ***is*** cool.
    	This ___is___ cool, too.
  * But this example won't work as expected:
    	***Hello** you*
    This is a wontfix bug because it would make the source too complex.
    Use this instead:
    	***Hello*** *you*

* inline Code

  You can produce inline code by surrounding it with backticks.

  	Use `rm -rf /` if you're a N00b.
  	Use ``rm -rf /`` if you're a N00b.
  	Use ```rm -rf /``` if you're a N00b.

  Double and triple backticks can be used if the code itself contains backticks.


Titles
------

Creating titles in smu is very easy. There are two different syntax styles. The
first is underlining with at least three characters:

	Heading
	=======
	
	Topic
	-----

This is very intuitive and self explaining. The resulting sourcecode looks like
this:

	<h1>Heading</h1>
	<h2>Topic</h2>

Use the following prefixes if you don't like underlining:

	# h1
	## h2
	### h3
	#### h4
	##### h5
	###### h6

Links
-----

The simplest way to define a link is with simple `<>`.

	<http://s01.de>

You can do the same for E-Mail addresses:

	<yourname@s01.de>

If you want to define a label for the url, you have to use a different syntax

	[smu - simple mark up](http://s01.de/~gottox/index.cgi/proj_smu)

The resulting HTML-Code

	<a href="http://s01.de/~gottox/index.cgi/proj_smu">smu - simple mark up</a></p>

Lists
-----

Defining lists is very straightforward:

	* Item 1
	* Item 2
	* Item 3

Result:

	<ul>
	<li>Item 1</li>
	<li>Item 2</li>
	<li>Item 3</li>
	</ul>

Defining ordered lists is also very easy:

	1. Item 1
	2. Item 2
	3. Item 3

Only the first number in a list is meaningful. All following list items are
continously counted. If you want a list starting at 2, you could write:

	2. Item 1
	2. Item 2
	2. Item 3

and get the following HTML which will render with the numbers 2, 3, 4:

	<ol start="2">
	<li>Item 1</li>
	<li>Item 2</li>
	<li>Item 3</li>
	</ol>

Code & Blockquote
-----------------

Use the `> ` as a line prefix for defining blockquotes. Blockquotes are
interpreted as well. This makes it possible to embed links, headings and even
other quotes into a quote:

	> Hello
	> This is a quote with a [link](http://s01.de/~gottox)

Result:
	<blockquote><p>
	Hello
	This is a quote with a <a href="http://s01.de/~gottox">link</a></p>
	</blockquote>


You can define a code block with a leading Tab or with __4__ leading spaces

		this.is(code)
	
	    this.is(code, too)

Result:
	<pre><code>this.is(code)</code></pre>
	<pre><code>this.is(code, too)
	</code></pre>

Please note that you can't use HTML or smu syntax in a code block.

Another way to write code blocks is to use code fences:

	```json
	{"some": "code"}
	```

This has two advantages:
* The optional language identifier will be turned into a `language-` class name
* You can keep the original indentation which helps when doing copy & paste

Tables
------

Tables can be generated with the following syntax:

	| Heading1 | Heading2 |
	| -------- | -------- |
	| Cell 1   | Cell2    |

Aligning the columns make the input nicer to read, but is not necessary to get
correct table output. You could just write

	| Heading1 | Heading2 |
	| --- | --- |
	| Cell 1 | Cell2 |

To align the content of table cells, use `|:--|` for left, `|--:|` for right
and `|:--:|` for centered alignment in the row which separates the header from
the table body.

	| Heading1 | Heading2 | Heading3 |
	| :------- | :------: | -------: |
	| Left     | Center   | Right    |

Other interesting stuff
-----------------------

* to insert a horizontal rule simple add `- - -` into an empty line:

  	Hello
  	- - -
  	Hello2

  Result:
  	<p>
  	Hello
  	<hr />
  	
  	Hello2</p>

* Any ASCII punctuation character may escaped by precedeing them with a
  backslash to avoid them being interpreted:

  	!"#$%&'()*+,-./:;<=>?@[]^_`{|}~\

* To force a linebreak simple add two spaces to the end of the line:

  	No linebreak
  	here.
  	But here is  
  	one.

embed HTML
----------

You can include arbitrary HTML code in your documents. The HTML will be
passed through to the resulting document without modification. This is a good
way to work around features that are missing in smu. If you don't want this
behaviour, use the `-n` flag when executing smu to stricly escape the HTML
tags.