diff --git a/dragonbat b/dragonbat
new file mode 100755
index 0000000..1b0fa5a
--- /dev/null
+++ b/dragonbat
@@ -0,0 +1,157 @@
+#!/usr/bin/perl
+
+use warnings FATAL => 'all';
+use strict;
+
+use Data::Dumper;
+
+# turn on autoflush
+$| = 1;
+
+sub booleq {
+    my ($s) = @_;
+    return sub { return $_[0] eq $s };
+}
+
+sub boolne {
+    my ($s) = @_;
+    return sub { return $_[0] ne $s };
+}
+
+sub numwh {
+    my ($s) = @_;
+    my ($n) = $s =~ m/^(.*) Wh$/;
+    return $n;
+}
+
+sub htime {
+    my ($s) = @_;
+    if ($s =~ m/^([0-9.]+) hours$/) {
+        return int($1 * 60);
+    } elsif ($s =~ m/^([0-9.]+) minutes$/) {
+        return int($1);
+    } else {
+        die "unknown time: $s";
+    }
+}
+
+sub stime {
+    my ($n) = @_;
+    my $h = $n / 60;
+    my $m = $n % 60;
+    return sprintf("%02d:%02d", $h, $m);
+}
+
+sub perc {
+    my ($n, $d) = @_;
+    return sprintf("%.1f%%", $n * 100 / $d);
+}
+
+sub charge_time {
+    my ($data) = @_;
+    return $data->{full} ? "--:--" : stime($data->{tcharge});
+}
+
+sub drain_time { 
+    my ($data) = @_;
+    return stime($data->{tdrain});
+}
+
+sub main {
+    if (@ARGV) {
+        my $t = $ARGV[0];
+        do {
+            run();
+            select(undef, undef, undef, $t);
+        } while (999);
+    } else {
+        run();
+    }
+}
+
+sub run {
+    my $data = init();
+    #print Dumper($data) . "\n";
+    display1($data, 5);
+}
+
+sub mac_meta {
+    return (
+        "ExternalConnected" => [["connected", booleq("Yes")]],
+        "AvgTimeToEmpty" => [["tdrain", \&int]],
+        "AvgTimeToFull" => [["tcharge", \&int]],
+        "MaxCapacity" => [["max", \&int]],
+        "CurrentCapacity" => [["cur", \&int]],
+        "FullyCharged" => [["full", booleq("Yes")]],
+        "IsCharging" => [["charging", booleq("Yes")]],
+    );
+}
+
+sub linux_meta {
+    return (
+        "energy" => [["cur", \&numwh]],
+        "energy-full" => [["max", \&numwh]],
+        "time to empty" => [["tdrain", \&htime]],
+        "time to full" => [["tcharge", \&htime]],
+        "state" => [
+            ["connected", boolne("discharging")],
+            ["full", booleq("fully-charged")],
+        ],
+    )
+}
+
+my $is_linux = $^O eq "linux";
+
+my %meta = $is_linux ? linux_meta() : mac_meta();
+
+sub mac_cmd {
+    return "ioreg -rc AppleSmartBattery";
+}
+
+sub mac_re {
+    return qr/^ *"(\w+)" = (.+)$/;
+}
+
+sub linux_cmd {
+    return "upower -i `upower -e | grep battery`";
+}
+
+sub linux_re {
+    return qr/^ *([^:]+): +(.+)$/;
+}
+
+sub init {
+    my $data = {};
+    $data->{tcharge} = 0;
+    my $cmd = $is_linux ? linux_cmd() : mac_cmd();
+    open(my $fh, "-|", $cmd);
+    my $re = $is_linux ? linux_re() : mac_re();
+    while (my $line = <$fh>) {
+        my ($key, $val) = $line =~ m/$re/;
+        next unless $key && $val;
+        my $r = $meta{$key};
+        next unless $r;
+        for my $p (@$r) {
+            $data->{$p->[0]} = $p->[1]->($val);
+        }
+    }
+    return $data;
+}
+
+sub icon {
+    my ($data) = @_;
+    return $data->{full} ? "☀" : "⚡" if $data->{connected};
+    return $data->{tdrain} < 30 ? "⚠" : "⌸";
+}
+
+sub display1 {
+    my ($data, $n) = @_;
+    my $c = $data->{connected};
+    my $p = perc($data->{cur}, $data->{max});
+    my $icon = icon($data);
+    my $f = $c ? \&charge_time : \&drain_time;
+    my $t = $f->($data);
+    printf("$icon %s (%s)\n", $t, $p);
+}
+
+main();