Anton Olsen . com

parsing some xml

Last night we looked at parsing urls out of the feeds. Tonight I'm going look at parsing a little more information. Specifically the channel title, item title, item enclosure, and item pubDate.

#!/bin/bash

BASEDIR="/mnt/usb0/mp3/podCast"
FEEDS="${BASEDIR}/feeds.lst"

while read URL ; do
   CHANNEL=""
   while read LINE; do
      TAG=$(echo ${LINE}|sed -n 's/<\([^>]*\).*/\1/p')
      # Bit of a hack to find the title of this channel.
      # We will assume that the first title we see is the channel title, future ones belong to the episodes.
      if [[ "title" = "${TAG}" ]] ; then
         if [[ "" = "${CHANNEL}" ]] ; then
            CHANNEL=$(echo ${LINE} | sed -n 's/<title>\([^<]*\)<\/title>/\1/p')
         else
            TITLE=$(echo ${LINE} | sed -n 's/<title>\([^<]*\)<\/title>/\1/p')
         fi
      elif [[ "link" = "${TAG}" ]] ; then
         # I found a few feeds that use link instead of enclosure.
         LINK=$(echo ${LINE} | sed -n 's/.*<link>\([^<]*\)<\/link>/\1/p')
      elif [[ "pubDate" = "${TAG}" ]] ; then
         # pubdate.  We'll use this in the id3tag (year, and comment) if the mp3 is missing them.
         DATE=$(echo ${LINE} | sed -n 's/.*<pubDate>\([^<]*\)<\/pubDate>/\1/p')
      elif [[ "${TAG}" =~ "^enclosure" ]] ; then
         # This should be the mp3 url, if it's blank, we'll try LINK if it ends in mp3.
         MP3=$(echo ${LINE} | sed -n 's/.*<enclosure url=["'\'']\([^"'\'']*\)["'\''].*/\1/p')
      elif [[ "${TAG}" = "/item" ]] ; then
         # Time to do something with the data we have.
         echo "Channel: "$CHANNEL
         echo "Title:   "$TITLE
         echo "Link:    "$LINK
         echo "Date:    "$DATE
         echo "MP3:     "$MP3
         echo ""
      fi
   done < <(wget -q -O - $URL)
done < <(grep -v -e '^[;#]' -e '^$' $FEEDS)

podcast.002.sh

Tomorrow I will pick the script apart and describe some of the parts, and maybe evolve it a bit. I'm sure there is a more efficient way to do some of the parsing. I will also start commenting the script and add caching for the xml files.