[Melbourne-pm] Promoting old-school file handles to io::handles

Toby Corkindale toby.corkindale at strategicdata.com.au
Mon Jan 11 22:29:20 PST 2010

Old-school Perl file handles looked like this:

   open(INPUT, "<$filename");

Then later they could be:

   open(my $input, "<$filename");

New-school filehandles are:

   my $input = IO::File->new($filename, 'r');

And interregnum filehandles were:

   my $fh = FileHandle->new($filename, 'r');

I want to have a method which accepts all, but operates upon them using 
new-school object methods, ie. $file->autoflush(1) or 

Currently I'm doing it via the following simplified code example, but I 
wondered if there was a more elegant solution?

package Thingy;
use Moose;
use IO::Handle;

has 'input' => (
   is => 'rw',
   isa => 'FileHandle', # Native Moose type, not same as FileHandle

around 'BUILDARGS' => sub {
   my ($orig, $class, $args) = @_;
   unless (blessed $args{input} and $args{input}->isa('IO::Handle')) {
     $args->{input} = IO::Handle->new->fdopen(fileno($args->{input}));
   return $args;

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