use XML::Parser;
use Data::Dumper;

my $parser = XML::Parser->new(Handlers =>
  {
    Start => sub { print Dumper [ @_[1 .. $#_] ] }
  }
);
$parser->parse(\*DATA);

__DATA__
<FILE>
<FOO xml:lang="en">
<BAR/>
</FOO>
<FOO xml:lang="ru">
<BAR/>
</FOO>
</FILE>