...to trust that

:raw:perlio:encoding(UTF-16LE):crlf
[download]
[download]

is the best, right way to handle Unicode text in Perl on Windows.

For older versions of Perl (<= 5.8.8), you'd need an additional :utf8 layer at the end, i.e.

    :raw:perlio:encoding(UTF-16LE):crlf:utf8
[download]

(although this isn't needed with newer versions, it doesn't do any harm either)

Without it, the strings would end up without the utf8 flag set (upon reading), which means that Perl wouldn't treat them as text/unicode strings in regex comparisons, etc., as it should. Similarly for writing.

$ hd Input.txt 
00000000  ff fe e4 00 62 00 63 00  0d 00 0a 00    |..ä.b.c.....|
[download]

#!/usr/bin/perl -w
use strict;
use Devel::Peek;

open my $input_fh,
    '<:raw:perlio:encoding(UTF-16):crlf', 'Input.txt';

my $line = <$input_fh>;
chomp $line;
Dump $line;
[download]

5.8.8 output (wrong):

SV = PV(0x69ae70) at 0x605000
  REFCNT = 1
  FLAGS = (PADBUSY,PADMY,POK,pPOK)
  PV = 0x6778e0 "\303\244bc"\0
  CUR = 4
  LEN = 80
[download]

Output with newer versions (correct):

SV = PV(0x750cb8) at 0x777cc8
  REFCNT = 1
  FLAGS = (PADMY,POK,pPOK,UTF8)
  PV = 0x86a070 "\303\244bc"\0 [UTF8 "\x{e4}bc"]
  CUR = 4
  LEN = 80
[download]

This seems to be the only thing that's been fixed in the meantime.

I think this only goes to prove your point that this is way too arcane for mere mortals... And, even though there is a "solution" to the issue, the current behavior of the :crlf layer is definitely a bug, IMHO. For one, it violates the principle of least surprise. Instead, the following straightforward approach (as anyone sane in his mind would glean from the existing documentation) should work:

open my $fh, '<:encoding(UTF-16LE)', ...
[download]

---

---

• Are you posting in the right place? Check out Where do I post X? to know for sure.
• Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:

  <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>

• Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
• Want more info? How to link or How to display code and escape characters are good places to start.