use warnings;
use strict;
use Text::Unaccent::PurePerl qw(unac_string);
use File::Slurp;
my $list = read_file('cote.html');
$_ = $list;
print unac_string("UTF-8", mixedregex());
$_ = "Côte";
print unac_string("UTF-8", mixedregex()), "\n";
use utf8;
$_ = $list;
print unac_string("UTF-8", mixedregex());
$_ = "Côte";
print unac_string("UTF-8", mixedregex()), "\n";

sub mixedregex {
    s[([0-7]{3})][chr oct $1]egr;
}