e621_can_handle() {
  local url="${1}"
  echo "${url}" | grep -qi 'e621.net/post/show/[0-9]*' || return 1
  taggery_id_filter=e621_id_filter
  taggery_fmturl="https://e621.net/post/show/%s"
  taggery_image_url_filter=e621_image_url_filter
  taggery_image_tags_filter=e621_image_tags_filter
}
e621_id_filter() {
  sed -e 's#^.*/post/show/\([0-9]\+\)\($\|/.*$\)#\1#'
}
e621_image_url_filter() {
  sed -e '/>Download</!d; s/^.* href="//; s/">Download.*$//'
}
e621_image_tags_filter() {
  sed -e 's/<\/li>/&\n/g' | sed -e '/id="tag-sidebar"/,/<\/ul>/!d; /class="tag-type-/!d; s/\([^?]\)<\/a>.*$/\1/; s/^.*>//; s/ /_/g'
}