Coninuouly print news from RSS

cnn_news.sh

#! /bin/sh

RSS_URL=http://feeds.bbci.co.uk/news/rss.xml
#RSS_URL=http://feeds.bbci.co.uk/news/rss.xml
PRINT_INTERVAL=${PRING_INTERVAL:-30}
FETCH_INTERVAL=${FETCH_INTERVAL:-600}


RSS=$(mktemp)
LOCK=$(mktemp)
latest_news_time=$(date --date -1day +%s)

print_news_from_rss_file() {
  xq -c '.rss.channel.item[]' $RSS | \
  tac | \
  while read -r record; do
    date="$(jq -r .pubDate <<<"$record")"
    epoch=$(date -d "$date" +%s)
    if [[ $epoch -gt $latest_news_time ]]; then
      latest_news_time=$epoch
      echo $latest_news_time >$LOCK
    else
      continue
    fi

    # Print headline
    echo -en '\e[1;30;41m'
    jq -r .title <<<"$record"
    echo -en '\e[0m\e[K'

    # Print publish date
    echo -en '\e[0;3m'
    echo "  $date"
    echo -en '\e[0m'
    printf '\n'

    # Print summary
    jq -r .description <<<"$record" | grep -Eo "^[^<]+"

    # Print link
    echo -en '\e[0;3;34m'
    jq -r .link <<<"$record"
    echo -en '\e[m'
    printf '\n\n'

    sleep $PRINT_INTERVAL
  done
}

while true; do
  if [ -s $RSS ]; then
    RSS_CTIME=$(stat -c %Y $RSS)
  else
    RSS_CTIME=0
  fi

  time_from_last_fetch=$(( $(date +%s) - $RSS_CTIME ))
  if [[ $time_from_last_fetch -le $FETCH_INTERVAL ]]; then
    sleep $(( $FETCH_INTERVAL - $time_from_last_fetch ))
  fi

  curl -s $RSS_URL >$RSS
  print_news_from_rss_file
  latest_news_time=$(cat $LOCK)
done