XML source¶
Xul scripts require an XML source to operate on. An XML source can be a local file, an URL (HTTP or FTP) or a pipe.
File¶
With xp you can select nodes in a local XML file with an XPath expression:
xp 'node()' entity.xml
Pipe¶
Redirect output (pipe) to a Xul script:
curl -s https://developer.apple.com/news/rss/news.rss | ppx
URL¶
libxml2 also supports loading XML through HTTP (and FTP). For example, to pretty print an RSS feed:
ppx http://feeds.launchpad.net/pytz/announcements.atom
Loading XML through HTTPS is not supported and will result in an
failed to load external entity error.
Try redirecting the HTTPS URL output to a Xul script. See the curl example above.
Examples¶
XHTML [1] is part of the family of XML markup languages. It’s obsolete.
Pretty print an XHTML document:
curl -s https://www.webstandards.org/learn/reference/templates/xhtml11/ | ppx
Validate an XHTML document with the
XHTML 1.0 strict DTD:
curl -s https://www.webstandards.org/learn/reference/templates/xhtml10t/ | validate -d examples/dtd/xhtml1-transitional.dtd
Print the link destinations in an XHTML document:
curl -s https://www.w3.org/1999/xhtml/ | xp -d html "//html:link/@href"
More XSDs and DTDs examples can be found in the Xul GitHub repository.
Footnotes