#!/usr/bin/perl

# Usage:
#   utf16to8.pl infile > outfile

use strict;
use warnings;

binmode(STDOUT, ':raw:encoding(UTF-8)');

for my $qfn (@ARGV) {
   # Assumes the presence of a BOM.
   open(my $fh, "<:raw:encoding(UTF-16)", $qfn)
      or die("Can't open \"$qfn\": $!\n");

   print while <$fh>;
}
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:raw is needed to disable the crlf layer if present. It would corrupt the data on the UTF-16 side, and the UTF-8 sides needs it to mirror the UTF-16 side.