anchor.diff:  
   # Function to create RSS/Atom feed for .torrent files
   function mk_rss {
  -  type="$1"		# fixme "history" / "planet"
  -  format="$2"		# fixme "pbf"
  -  web_dir="$3"		# fixme "pbf/full-history" or "pbf"
  -  disk_dir="$4"		# fixme "/store/planet/pbf/full-history"
  +  type="$1"
  +  format="$2"
  +  web_dir="$3"
  +  disk_dir="$4"
     old_pwd="$PWD"
     rss_name="${type}-${format}-rss.xml"
     rss_path="${old_pwd}/${rss_name}"
  
positive.code: 
    # RSS header
    printf '%s\n' \
       '<?xml version="1.0" encoding="utf-8"?>' \
       '<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">' \
       '<channel>' > "${rss_path}"
    cat >> "${rss_path}" <<__EOF
       <title>OpenStreetMap planet torrent RSS</title>
       <link>${rss_baseurl}</link>
       <atom:link href="${rss_dirurl}/${rss_name}" rel="self" type="application/rss+xml" />
       <description>RSS feed for ${type}.osm.${format}.torrent</description>
       <language>en-us</language>
  
negative.code:   do
      cat >> "${rss_path}" <<__EOF
       <item>
          <title>${tf}</title>
          <guid>${rss_dirurl}/${tf}</guid>
          <pubDate>`date -R -r ${tf}`</pubDate>
          <category>OpenStreetMap</category>
          <link>${rss_dirurl}/${tf}</link>
          <enclosure url="${rss_dirurl}/${tf}" length="`find -maxdepth 1 -name ${tf%.torrent} -printf "%s"`" type="application/x-bittorrent" />
          <description>OSM Torrent ${tf} (torrent size: `find -maxdepth 1 -name ${tf} -printf "%s"`)</description>
       </item>
  __EOF
    done
  
    # RSS footer
    printf '</channel>\n</rss>\n' >> "${rss_path}"
    cd "${old_pwd}"
    mv "${rss_path}" "${disk_dir}"
  }
  
  