Lost in compressed encodings

Skeeve has asked for the wisdom of the Perl Monks concerning the following question:

This is a follow up of my Lost in encodings question.

Thanks to the answers given there I was able to solve that issue, but now I'm clueless again as I now need to read in compressed (gzip) UTF-8 files and I do not know how to convince perl to read them as UTF-8.

My code for opening the files is:

    open my $in, '<:utf8', $filename or die "Can't read $filename: $!\
+n";
    if ($filename=~/\.gz$/) {
        $in= new IO::Uncompress::Gunzip $in, { AutoClose => 1 };
    }
[download]

When reading uncompressed data, it works fine as I could verify with the help given in my previous thread. I did so by setting the debugger to UTF-8. When reading uncompressed data the Umlaut "ь" is correctly displayed as "ь". When reading the same data from a compressed file the "ь" is displayed as "Гј".

I have no idea how to make perl consider the compressed data as UTF-8?

s$$([},&%#}/&/]+}%&{})*;#$&&s&&$^X.($'^"%]=\&(|?*{%
+.+=%;.#_}\&"^"-+%*).}%:##%}={~=~:.")&e&&s""`$''`"e

Comment on Lost in compressed encodings Select or Download Code

Replies are listed 'Best First'.
Re: Lost in compressed encodings by Corion (Patriarch) on Apr 06, 2020 at 08:41 UTC
The order of decompressing and decoding matters. You want to first uncompress and then decode. If you want to cheat, you can use PerlIO::gzip: `my $in; my $open_mode = '<:raw'; if ($filename=~/\.gz$/) { $open_mode .= ':gzip'; } $open_mode .= ':utf8'; open my $in, $open_mode, $filename or die "Can't read $filename: $ +!\n";` [download] If you want to stay with IO::Uncompress::Gunzip, I think the following should work, but I don't know if `->binmode()` also applies other encodings properly: `my $in; if ($filename=~/\.gz$/) { $in = new IO::Uncompress::Gunzip $in, { AutoClose => 1 }; } else { open $in, '<:raw', $filename or die "Can't read $filename: $!\ +n"; }; binmode $in, ':utf8';` [download]	[reply] [d/l] [select]
Re^2: Lost in compressed encodings by Skeeve (Parson) on Apr 06, 2020 at 08:53 UTC
Thanks Corion. I already had the feeling that the sequence somehow is the issue. Unfortunately providing binmode after IO::Uncompress did not help. My changed code: `open my $in, '<:raw', $filename or die "Can't read $filename: $!\n +"; if ($filename=~/\.gz$/) { $in= new IO::Uncompress::Gunzip $in, { AutoClose => 1 }; } binmode $in, ':utf8';` [download] It still works with uncompressed and not with compressed data. Seems I will have to manually decode each line… `s$$([},&%#}/&/]+}%&{});#$&&s&&$^X.($'^"%]=\&(\|?{%` `+`.+=%;.#_}\&"^"-+%*).}%:##%}={~=~:.")&e&&s""`$''`"e	[reply] [d/l] [select]
Re^3: Lost in compressed encodings by Corion (Patriarch) on Apr 06, 2020 at 08:59 UTC
I think that IO::Uncompress::Gunzip only understands `->binmode()` and not `->binmode(':utf8');`. The documentation (now that I read it ...) even says: This is a noop provided for completeness. If you are able to install PerlIO::gzip, that one should work with stacking other decoding mechanisms on top of it. If you have a gzip binary available, you can use that to decompress: `my $in; if( $filename =~ /\.gz$/ ) { open $fh, "gzip -cd "$filename" \|' or die "Can't read from gzip $filename: $!/$?"; } else { open $in, '<:raw', $filename or die "Can't read $filename: $!\n"; }; binmode $fh, ':utf8';` [download]	[reply] [d/l] [select]
Re^4: Lost in compressed encodings by Skeeve (Parson) on Apr 06, 2020 at 09:19 UTC
Re^5: Lost in compressed encodings by Tux (Canon) on Apr 06, 2020 at 10:49 UTC
Re: Lost in compressed encodings by jo37 (Deacon) on Apr 06, 2020 at 16:23 UTC
You are overwriting the file handle $in with the newly created by `IO::Uncompress::Gunzip`. I can't tell the consequences, but it does not look sane to me. Greetings, -jo `$gryYup$d0ylprbpriprrYpkJl2xyl~rzg??P~5lp2hyl0p$`	[reply] [d/l]
Re: Lost in compressed encodings by Anonymous Monk on Apr 07, 2020 at 16:46 UTC
Nitpick: you should probably be using `:encoding(utf-8)` rather than just `:utf8`. See perlunifaq for the details.	[reply] [d/l] [select]
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