####################################################################
# Look at the first bytes of the content
# FE FF -> utf-16be
# FF FE -> utf-16le
# EF BB BF -> utf-8
return "utf-16be" if $resp->content =~ m/^\xFE\xFF/;
return "utf-16le" if $resp->content =~ m/^\xFF\xFE/;
return "utf-8"    if $resp->content =~ m/^\xEF\xBB\xBF/;

####################################################################
# Use the header
# content-type: text/html; charset=XXX
my $ct = $resp->{_headers}->{'content-type'} || "";
my ($cs) = lc($ct) =~ m/\s+charset\s*=\s*["']*([^\s'";]*)/;
$cs =~ s/utf=/utf\-/g if defined($cs);
return $cs if defined($cs) && $cs ne "";

####################################################################
# Use the META tag
# <meta http-equiv="content-type" content="text/html; charset=XXX">
($ct) = $resp->content =~
 m/<meta http-equiv=["']?content-type["']? content=["']([^"']*)["']/i;
($cs) = $ct =~ m/\s+charset\s*=\s*([^\s']*)/
  if defined($ct) && $ct ne "";
$cs =~ s/utf=8/utf\-8/ig if defined($cs);
return $cs if defined($cs) && $cs ne "";

####################################################################
# Default character set based on encoding of characters
return "utf-8" if $resp->content =~ m/[^\x00-\x7F]/;
return "iso-8859-1";