use open qw/:locale/;

BEGIN {
    require locale;
    locale->import() if shift;
}

use Data::Dumper qw( Dumper );

sub dump_str {
    my ($s) = @_;
    my $internal_enc = utf8::is_utf8($s) ? "utf8" : "iso-latin-1";
    local $Data::Dumper::Useqq  = 1;
    local $Data::Dumper::Terse  = 1;
    local $Data::Dumper::Indent = 0;
    print("Input = ", Dumper($s), " [$internal_enc]\n");
}

print(join(':', PerlIO::get_layers(STDIN)), "\n");

my $s = <>;
dump_str($s);

print "Outside char class: ", $s =~ m/\w/   ? "" : "no ", "match\n";
print "Inside char class:  ", $s =~ m/[\w]/ ? "" : "no ", "match\n";

##</code><code>##

$ perl -e'binmode STDOUT, ":encoding(UTF-8)"; print chr 0xC9' | LANG=en_CA.utf8 perl a.pl 0
unix:perlio:utf8
Input = "\x{c9}" [utf8]
Outside char class: match
Inside char class:  match

$ perl -e'binmode STDOUT, ":encoding(UTF-8)"; print chr 0xC9' | LANG=en_CA.utf8 perl a.pl 1
unix:perlio:utf8
Input = "\x{c9}" [utf8]
Outside char class: no match
Inside char class:  match