::fixture-ready::
$ find public -name '*.html' -print
public/about.html
public/draft.html
public/blog/post.html
public/index.html
::exit-code::0
$ find public -name '*.html' -print | sed 's#^public#https://example.com#' | while read -r url; do grep -q "$url" public/sitemap.xml || echo "$url"; done
https://example.com/draft.html
https://example.com/index.html
::exit-code::0