use strict;
use warnings;

my $file = $ARGV[0];
open my $fh, '<', $file or die "cannot open $file";

# pause some second to go to inspect the process manager
sleep 5;

# the diamond op <> slurp the whole file when in list context (the array to the left force list context)
my @array_of whole_file = <$fh>;

sleep 5;