libhtml-encoding-perl binary package in Ubuntu Bionic amd64

 HTML::Encoding helps to determine the encoding of HTML and XML/XHTML
 documents. It can export the following functions:
 .
  encoding_from_content - Extracts charset from the Content-Type header value.
  encoding_from_byte_order_mark - Read byte order mark from an octet sequence.
  encoding_from_xml_declaration - Extract encoding XML or text declaration.
  encoding_from_first_chars - Can be useful to distinguish UTF-16LE from UTF-8.
  encoding_from_meta_element - Looks at <meta http-equiv=Content-Type.....>.
  encoding_from_xml_document - A best guess from a list of suspected encodings.
  encoding_from_html_document - A best guess from a list of suspected encodings.
  encoding_from_http_message - Takes an HTTP::Message and returns the encoding.

Source package