LWP doesn't decode anything unless you use ->decoded_content. If you use ->content, you get the raw bytes returned by the web server. By using '>:encoding(iso-8859-5)', you are re-encoding chars that have already been encoded using windows-1251. That makes no sense. You need to undo the first encoding before encoding again. 

use Encode qw( decode from_to );

# Outputs windows-1251 text
open my $fh, '>', $qfn;
print $fh $response->content;

# Outputs iso-8859-5 text
open my $fh, '>', $qfn;
$content = $response->content;
from_to($content, 'windows-1251', 'iso-8859-5');
print $fh $content;

# Outputs iso-8859-5 text
open my $fh, '>:encoding(iso-8859-5)', $qfn;
print $fh decode('windows-1251', $response->content);

# Outputs iso-8859-5 text, assuming
# the content encoding is detected.
open my $fh, '>:encoding(iso-8859-5)', $qfn;
print $fh $response->decoded_content;

[download]

So, 

my $file = $response->content;

[download]
should be one of 
my $file = $response->decoded_content;

[download]
or 
my $file = decode('windows-1251', $response->content);

[download]

(iso-8859-5 is the iso name for windows-1251)

No. They're quite different.
windows-1251
iso-8859-5

In reply to Re: Downloading webpages with non-ASCII characters by ikegami
in thread Downloading webpages with non-ASCII characters by CountZero

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