Sub-class IO::File and you've already got it. Should be a no-brainer.

#!/usr/bin/perl -w

package IO::File::AutoChomp;

use base 'IO::File';

sub getline
{
        my ($self) = @_;

        # Awkward, I know.
        return (map { chomp; $_ } $self->SUPER::getline())[0];
}

sub getlines
{
        my ($self) = @_;

        return map { chomp; $_ } $self->SUPER::getlines();
}

package main;

my $fh = IO::File::AutoChomp->new_from_fd(*DATA, "r") || die "Could no
+t open DATA\n";

print join(",", $fh->getlines());
$fh->close();

__END__
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