#!/usr/bin/perl -w
use Memory::Usage;
use vars qw ($muse);
$muse = Memory::Usage->new();

my $name = "bigfile"; # file size: 640MB
my $READIN = qw (<);
my $EXT;
my @data = ();
my $d = \@data;
die "Error opening file: $name" if ( !open $EXT, $READIN, $name );
$muse->record('Begin');

@data = <$EXT>; # option 1
#@$d = <$EXT>;  # option 2

close($EXT);
$muse->record('After file read');
$muse->dump();