This is a simple piece of Perl I wrote to see what percentage my laptop battery was. The die needs to be more descriptive and I also need to take out the hardcoded values for a full battery, but it gets the job done faster than cat and scanning. 
#!/usr/bin/perl
use warnings;
use strict;
use diagnostics;
my $status;
open (BATT, "/proc/acpi/battery/BAT0/state") || die("Can't Open: $!");
while (<BATT>) {
  if ($_ =~ /(charging state:)(\s+)(\w+)/ ) {
    $status = $3;
    }
  if ($_ =~ /(:)(\s+)(\d*)(\s+)(mAh)/ ) {
     print "\n";
     my $perc = $3/2791;
     printf "The battery is %s", $status;
     print "\n";
     printf "Battery percentage is: %.0f", $perc*100;
     print "\n-----------------------------\n\n";
     } else {
     print "Incorrect Format";
     }
  }
close BATT;

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In reply to Checking Laptop battery info by /dev/trash

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