Hexdump is a hexadecimal representation of bytes in a file. You can obtain it by running something like this:

open my $f,"<:raw","file.csv" || die $!;
my $c;
for (1..8) {
 for (1..16) {
  read $f,$c,1 || exit 0;
  print unpack "H2",$c;
 }
 print "\n";
}
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You can rewrite unix2dos in Perl using PerlIO :crlf output layer.