package rdw;
use strict;
use warnings;

sub PUSHED { bless \*PUSHED,$_[0] }
sub FILL {
    my ($length, $record);
    read $_[1], $length, 1;
    return undef if eof $_[1];
    read $_[1], $record, $length;
    # uncomment next line to see it is actually working
    # print "$record\n";
    return $record;
}
sub WRITE { return undef }

package main;

open( my $in, '<:via(rdw)', 'foo.txt' ) or die $!;
while ( <$in> ) {
    print "$_\n";
}
__END__
# foo.txt - output is aababc
1a2ab3abc