Question

I have this simple base class (Module):

package XMSP::File;
use parent 'IO::File';

sub new {
    my ($self,@args) = @_;
    my $object = {};

    bless($object,$self);
    $object->SUPER::new(@args);

    return $object;
}

sub open {
    my ($self,@args) = @_;
    $self->SUPER::open(@args);
}

sub close {
    my ($self,@args) = @_;
    $self->SUPER::close(@args);
}
1;

Script:

#!/usr/bin/env perl
use strict;
use warnings;
use XMSP::File;

my $file = XMSP::File->new("< $0");

if (defined $file) {
    print "First Ok\n";
    $file->close();
}

$file->open("< file");

if (defined $file) {
    print "Second Ok\n";
}

On my script I load it using use … I use the ctor (new) to create a new object, etc. but when I close it, it dies with the following error:

First Ok
Not a GLOB reference at /usr/lib/perl/5.10/IO/Handle.pm line 115.

I can’t really figure it out why.

Answer 1

Instead of letting IO::File create the object, you create it, and you create it completely wrong. You didn’t even use the right variable type (hash vs glob). Let IO::File create the object.

sub new {
    my ($class, @args) = @_;
    my $self = $class->SUPER::new(@args);
    return $self;
}

Note that this method is completely redundant. I presume you intend to do additional work in it.