use warnings;
use strict;

my @cmd = ('C:\Program Files\Mozilla Firefox\firefox.exe',
	'--version');
die "\@cmd must have more than one element" unless @cmd>1;
open my $fh, '-|', @cmd or die $!;
my $out = do { local $/; <$fh> };  # slurp
close $fh or die $! ? $! : "\$?=$?";
chomp $out;