It turns out that most of the confusion was due to File::Slurp RT#84918, submitted by our friend corion. "File-Slurp: read_file() ignores binmode option for short files". If only I had suspected File::Slurp earlier, I could have saved myself (and others) some time.

Here's a complete working example. Note, you must binmode the filehandle with ":encoding(rot13)", not the more terse ":rot13" (which simply won't work). Also, there's no need to explicitly call define_encoding from Encode within the calling package; the line __PACKAGE__->Define('rot13'); does that for us.

package Encode::ROT13;
use strict;
use warnings;

use parent qw( Encode::Encoding );

sub encode($$;$){
  my( $obj, $str, $chk ) = @_;
  $str =~ tr/A-Za-z/N-ZA-Mn-za-m/;
  $_[1] = '' if $chk; # $_[1] is aliased through the call. Inplace edi
+t.
                      # (Remove whole string unless there's an error.)
  return $str;
}

no warnings 'once';
*decode = \&encode; # Because rot13( rot13() ) is a round-trip.

__PACKAGE__->Define( 'rot13' );

1;


package main;

use strict;
use warnings;

binmode \*DATA, ':encoding(rot13)';

chomp( my @words = <DATA> );

print "$_\n" for @words;

__DATA__
Apple
cat
dog
strawberry
watermelon

[download]

...and the output...

Nccyr
png
qbt
fgenjoreel
jngrezryba

[download]

...now on to learn how to use the enc2xs tool.


Dave

In reply to Re: Creating (and using) a custom encoding. (SOLUTION) by davido
in thread Creating (and using) a custom encoding. by davido

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