
# 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 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>
````````````````````````````````


