CRLF translation with Unicode in Perl

Question

I'm trying to write to a Unicode (UCS-2 Little Endian) file in Perl on Windows, like this.

open my $f, ">$fName" or die "can't write $fName\n";
binmode $f, ':raw:encoding(UCS-2LE)';
print $f, "ohai\ni can haz unicodez?\nkthxbye\n";
close $f;

It basically works except I no longer get the automatic LF -> CR/LF translation on output that I get on regular text files. (The output files just have LF) If I leave out :raw or add :crlf in the "binmode" call, then the output file is garbled. I've tried re-ordering the "directives" (i.e. :encoding before :raw) and can't get it to work. The same problem exists for reading.

Answer 1

The :crlf layer does a simple byte mapping of 0x0A -> 0x0D 0x0A (\n --> \r\n) in the output stream, but for the most part this isn't valid in any wide character encoding.

How about using a raw mode but explicitly print the CR?

print $f "ohai\r\ni can haz unicodez?\r\nkthxbye\r\n";

Or if portability is a concern, discover and explicitly use the correct line ending:

## never mind - $/ doesn't work
# print $f "ohai$/i can haz unicodez?$/kthxbye$/";

open DUMMY, '>', 'dummy'; print DUMMY "\n"; close DUMMY;
open DUMMY, '<:raw', 'dummy'; $EOL = <DUMMY>; close DUMMY;
unlink 'dummy';

...

print $f "ohai${EOL}i can haz unicodez?${EOL}kthxbye${EOL}";

Answer 2

This works for me on windows:

open my $f, ">:encoding(UCS-2LE):crlf", "test.txt";
print $f "ohai\ni can haz unicodez?\nkthxbye\n";
close $f;

Yielding UCS-16 LE output in test.txt of

ohai
i can haz unicodez?
kthxbye