in reply to Re^5: Processing an encoded file backwards
in thread Processing an encoded file backwards

Haukex++

NICE example for ambiguity of UTF-16 if you don't get the start right!!!

For clarification: your point is that "\xFA" (first block) and "\xDD" (second block) should raise errors?

use warnings;
use strict;
use Encode qw/decode/;
use Data::Dump qw/dd/;


dd decode('UTF-16-BE', "\x3D\xDD\xFA", Encode::FB_CROAK|Encode::LEAVE_
+SRC );
dd decode('UTF-16-BE', "\xFA",         Encode::FB_CROAK|Encode::LEAVE_
+SRC );

dd decode('UTF-16-LE', "\xD8\xFA\xDD", Encode::FB_CROAK|Encode::LEAVE_
+SRC );
dd decode('UTF-16-LE', "\xDD",         Encode::FB_CROAK|Encode::LEAVE_
+SRC);

__END__

"\x{3DDD}"
""
"\x{FAD8}"
""

[download]

I agree, looks like a bug we should report.

A really strange one too ...

> Personally I'd just make a version for UTF-8 and UTF-16, and any others as needed, or other encodings can be converted to the supported ones.

I don't even know other wide encodings except unicode , so I prefer relying on Encode for utf8 and make sure utf16 are read modulo 4 bytes 2 bytes.

update

From the docs

    As of version 2.12, "Encode" supports coderef values for "CHECK"; 
+see
    below.

    NOTE: Not all encodings support this feature. Some encodings ignor
+e the
    *CHECK* argument. For example, Encode::Unicode ignores *CHECK* and
+ it
    always croaks on error.

[download]

... but it doesn't croak

Cheers Rolf
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery FootballPerl is like chess, only without the dice

Replies are listed 'Best First'.
Re^7: Processing an encoded file backwards (updated)
by choroba (Cardinal) on Jan 18, 2020 at 23:13 UTC
    What Perl version? I'm getting

    UTF-16BE:Partial character at /home/choroba/1.pl line 8.

    [download]
    in 5.26.1.

    map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]
[reply]
[d/l]
[select]
      That's what I get in git-bash with 5.26.2

      probably a windows problem?

      $ perl
use warnings;
use strict;
use Encode qw/decode/;
use Data::Dumper qw/Dumper/;


warn Dumper decode('UTF-16-BE', "\x3D\xDD\xFA", Encode::FB_CROAK|Encod
+e::LEAVE_SRC );
warn Dumper decode('UTF-16-BE', "\xFA",         Encode::FB_CROAK|Encod
+e::LEAVE_SRC );

warn Dumper decode('UTF-16-LE', "\xD8\xFA\xDD", Encode::FB_CROAK|Encod
+e::LEAVE_SRC );
warn Dumper decode('UTF-16-LE', "\xDD",         Encode::FB_CROAK|Encod
+e::LEAVE_SRC);

__END__
$VAR1 = "\x{3ddd}";
$VAR1 = '';
$VAR1 = "\x{fad8}";
$VAR1 = '';

 MINGW64 ~
$ perl -v

This is perl 5, version 26, subversion 2 (v5.26.2) built for x86_64-ms
+ys-thread-multi

      [download]

      Cheers Rolf
      (addicted to the Perl Programming Language :)
      Wikisyntax for the Monastery FootballPerl is like chess, only without the dice

[reply]
[d/l]
      > What Perl version?

      'This is perl 5, version 24, subversion 1 (v5.24.1) built for MSWin32-x64-multi-thread'

      does it die?

      Cheers Rolf
      (addicted to the Perl Programming Language :)
      Wikisyntax for the Monastery FootballPerl is like chess, only without the dice

[reply]
        Yes, with exit code 2.

        This is perl 5, version 26, subversion 1 (v5.26.1) built for x86_64-linux-thread-multi

        map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]
[reply]
[d/l]

        Just a note on this subthread: Encode can be upgraded separately from Perl.

[reply]

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