pretty print xml by xmllint

gistfile1.sh

$ node build-opds.js 
<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom" xmlns:dc="http://purl.org/dc/terms/" xmlns:opds="http://opds-spec.org/2010/catalog"><id>urn:uuid:433a5d6a-0b8c-4933-af65-4ca4f02763eb</id><title>feed title</title><updated>2010-01-10T10:01:11Z</updated><author><name>Feed author</name><uri>http://opds-spec.org</uri><email>[email protected]</email></author><link rel="self" type="application/atom+xml;profile=opds-catalog;kind=acquisition" href="/opds-catalogs/unpopular.xml"/><entry/></feed>

$ node build-opds.js | xmllint --format -
<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom" xmlns:dc="http://purl.org/dc/terms/" xmlns:opds="http://opds-spec.org/2010/catalog">
  <id>urn:uuid:433a5d6a-0b8c-4933-af65-4ca4f02763eb</id>
  <title>feed title</title>
  <updated>2010-01-10T10:01:11Z</updated>
  <author>
    <name>Feed author</name>
    <uri>http://opds-spec.org</uri>
    <email>[email protected]</email>
  </author>
  <link rel="self" type="application/atom+xml;profile=opds-catalog;kind=acquisition" href="/opds-catalogs/unpopular.xml"/>
  <entry/>
</feed>