How to get a defined ${^OPEN}?

Question

What changes are required in this code to get a defined ${^OPEN}?

#!/usr/bin/env perl
use warnings;
use strict;
use open qw( :std :utf8 );

print ${^OPEN};

Use of uninitialized value $^OPEN in print at ./perl.pl line 6.

I would like to know if `binmode STDIN ':encoding(...)` is set. If is set I would let return a subroutine decoded strings else not decoded strings. — sid_com, Jul 17 '14 at 12:58
@sid_com, check `PerlIO::get_layers(\*STDIN, details => 1)`. — tobyink, Jul 17 '14 at 13:04

score 0 · Answer 1 · edited May 23 '17 at 11:57

This is quite uneasy way. May be it is better to user more readable Perl.

:utf8 outputs utf-8 charset but does not checks its validity, you should not use this one, except for one liners. Use :encoding(UTF-8) instead.

Please refer to this post How differs the open pragma with different utf8? for more information about different types of utf-8 input/outputs.

I even do not know what could possibly be ${^OPEN} variable. I advice you not to use it at all, as you should not use magic punctuation.

Hope it helps

1 Answers1