use warnings;
use strict;
use IPC::Run3 'run3';

my $cmd = 'C:\Program Files\Mozilla Firefox\firefox.exe';
run3 [$cmd,'--version'], undef, \my $out or die "run3: $!";
die "\$?=$?" if $?;
chomp $out;

##</code><code>##

use warnings;
use strict;

my $cmd = 'C:\Program Files\Mozilla Firefox\firefox.exe';
open my $fh, '-|', $cmd, '--version' or die $!;
my $out = do { local $/; <$fh> };  # slurp
close $fh or die $! ? $! : "\$?=$?";
chomp $out;