gelbooru_can_handle() {
  local url="${1}"
  echo "${url}" | grep -qi 'gelbooru.com/.*id=[0-9]*' || return 1
  taggery_id_filter=gelbooru_id_filter
  taggery_fmturl="http://gelbooru.com/index.php?page=post&s=view&id=%s"
  taggery_image_referer=gelbooru_image_referer
  taggery_image_url_filter=gelbooru_image_url_filter
  taggery_image_tags_filter=gelbooru_image_tags_filter
}
gelbooru_id_filter() {
  sed -e 's#^.*id=\([0-9]\+\)\($\|&.*$\)#\1#'
}
gelbooru_image_referer() {
  echo "http://www.gelbooru.com/index.php?page=post&s=view&id=${1}"
}
gelbooru_image_url_filter() {
  sed -e '/>Original image</!d; s/>Original image.*//i; s/^.*<a //i; s/^.*href="\([^"]*\)".*$/\1/i'
}
gelbooru_image_tags_filter() {
  sed -e '/id="tag-sidebar"/!d; s/<\/li>/&\n/g' | sed -e '/class="tag-type-/!d; s/\([^?]\)<\/a>.*$/\1/; s/^.*>//; s/ /_/g'
}