use warnings;
use List::Util qw( max sum );
-my $width = $ENV{COLUMNS} || 80;
+use Getopt::Long;
+GetOptions(\my %opt,
+ 'width|w=i',
+) or exit 64; # EX_USAGE
+$opt{width} ||= $ENV{COLUMNS} || 80;
my @lines = readline;
chomp for @lines;
my @order = sort { $b <=> $a } @values;
my $lenval = 1 + int log($order[0]) / log 10; # max string length
my $len = 1 + max map { length } @lines; # left padding
-my $size = ($width - $lenval - $len) / $order[0]; # bar multiplication
+my $size = ($opt{width} - $lenval - $len) / $order[0]; # bar multiplication
sub orderpos { ($order[$_[0]] + $order[$_[0] + .5]) / 2 * $size }
my @barmark;