
# Permissive URL Autolinks

With the flag `MD_FLAG_PERMISSIVEURLAUTOLINKS`, MD4C enables more permissive recognition
of URLs and transform them to autolinks, even if they do not exactly follow the syntax
of autolink as specified in CommonMark specification.

This is a standard CommonMark autolink:

```````````````````````````````` example
Homepage: <https://github.com/mity/md4c>
.
<p>Homepage: <a href="https://github.com/mity/md4c">https://github.com/mity/md4c</a></p>
````````````````````````````````

With the permissive autolinks enabled, this is sufficient:

```````````````````````````````` example
Homepage: https://github.com/mity/md4c
.
<p>Homepage: <a href="https://github.com/mity/md4c">https://github.com/mity/md4c</a></p>
````````````````````````````````

But this permissive autolink feature can work only for very widely used URL
schemes, in alphabetical order `ftp:`, `http:`, `https:`.

That's why this is not a permissive autolink:

```````````````````````````````` example
ssh://root@example.com
.
<p>ssh://root@example.com</p>
````````````````````````````````

The same rules for path validation as for permissivve WWW autolinks apply.
Therefore the final question mark here is not part of the autolink:

```````````````````````````````` example
Have you ever visited http://www.zombo.com?
.
<p>Have you ever visited <a href="http://www.zombo.com">http://www.zombo.com</a>?</p>
````````````````````````````````

But in contrast, in this example it is:

```````````````````````````````` example
http://www.bing.com/search?q=md4c
.
<p><a href="http://www.bing.com/search?q=md4c">http://www.bing.com/search?q=md4c</a></p>
````````````````````````````````

And finally one complex example:

```````````````````````````````` example
http://commonmark.org

(Visit https://encrypted.google.com/search?q=Markup+(business))

Anonymous FTP is available at ftp://foo.bar.baz.
.
<p><a href="http://commonmark.org">http://commonmark.org</a></p>
<p>(Visit <a href="https://encrypted.google.com/search?q=Markup+(business)">https://encrypted.google.com/search?q=Markup+(business)</a>)</p>
<p>Anonymous FTP is available at <a href="ftp://foo.bar.baz">ftp://foo.bar.baz</a>.</p>
````````````````````````````````


## GitHub Issues

### [Issue 53](https://github.com/mity/md4c/issues/53)

```````````````````````````````` example
This is [link](http://github.com/).
.
<p>This is <a href="http://github.com/">link</a>.</p>
````````````````````````````````

```````````````````````````````` example
This is [link](http://github.com/)X
.
<p>This is <a href="http://github.com/">link</a>X</p>
````````````````````````````````


## [Issue 76](https://github.com/mity/md4c/issues/76)

```````````````````````````````` example
*(http://example.com)*
.
<p><em>(<a href="http://example.com">http://example.com</a>)</em></p>
````````````````````````````````


## [Issue 152](https://github.com/mity/md4c/issues/152)

```````````````````````````````` example
[http://example.com](http://example.com)
.
<p><a href="http://example.com">http://example.com</a></p>
````````````````````````````````
