$ perl -Mblib -MPerlIO::via::xz -wE'open my $fh, "<:via(xz)", "files/plain.xz";print scalar<$fh>'
Lorem ipsum dolor sit amet,   consectetur adipiscing elit,

$ perl -Mblib -MPerlIO::via::xz -wE'open my $fh, "<:via(xz)", "files/plain.xz";$/=undef;print scalar<$fh>'