use Sys::uptime;
    my $uptime;
    tie $uptime, 'Sys::uptime';

    printf "Load average over the last minute: %s\n",
        $uptime->load('one');

##</code><code>##

    package Sys::uptime;
    use Class::Struct;
    use Carp;
    use strict;

##</code><code>##

    my $WAIT_CACHE = 5;

##</code><code>##

    struct 'Uptime' => [
        'uptime'    => '$',
        'users'     => '$',
        'load'      => '%',
        'as_string' => '$',
    ];

##</code><code>##

    sub TIESCALAR {
        my $class = shift;
        my $self = {
            up          => new Uptime,
            last_update => 0
        };
        bless $self, $class;
        $self;
    }

##</code><code>##

    printf "Load average over the last minute: %s\n",
        $uptime->load('one');

##</code><code>##

    sub FETCH {
        my $self = shift;
        if (time - $self->{last_update} > $WAIT_CACHE) {
            $self->{last_update} = time;
            my($str, $upt, $users, $one, $five, $fifteen) =
                get_uptime();

            my $up = $self->{up};
            $up->as_string($str);
            $up->uptime($upt);
            $up->users($users);
            $up->load('one', $one);
            $up->load('five', $five);
            $up->load('fifteen', $fifteen);
        }
        return $self->{up};
    }

##</code><code>##

    sub get_uptime {
        local $_ = `uptime`;
        chomp;
        if (/^\s+\S+\s+                   # opening cruft
            up\s+(.+?(,)?.+?),             # uptime
            \s+(\d+)\s+users?,          # number of users
            \s+load\s+averages?:\s+     # load average...
            (.+?),\s+(.+?),\s+(.+?)\s*  # ...and values
            $/x) {
            return($_, $1, $2, $3, $4, $5);
        }
        else {
            croak "What was that? Bad uptime.";
        }
    }

##</code><code>##

    package Sys::uptime;
    use Class::Struct;
    use Carp;
    use strict;

    my $WAIT_CACHE = 5;

    struct 'Uptime' => [
        'uptime'    => '$',
        'users'     => '$',
        'load'      => '%',
        'as_string' => '$',
    ];

    sub TIESCALAR {
        my $class = shift;
        my $self = {
            up          => new Uptime,
            last_update => 0
        };
        bless $self, $class;
        $self;
    }

    sub FETCH {
        my $self = shift;
        if (time - $self->{last_update} > $WAIT_CACHE) {
            $self->{last_update} = time;
            my($str, $upt, $users, $one, $five, $fifteen) =
                get_uptime();

            my $up = $self->{up};
            $up->as_string($str);
            $up->uptime($upt);
            $up->users($users);
            $up->load('one', $one);
            $up->load('five', $five);
            $up->load('fifteen', $fifteen);
        }
        return $self->{up};
    }

    sub get_uptime {
        local $_ = `uptime`;
        chomp;
        if (/^\s+\S+\s+                   # opening cruft
            up\s+(.+?,?.+?),             # uptime
            \s+(\d+)\s+users?,          # number of users
            \s+load\s+averages?:\s+     # load average...
            (.+?),\s+(.+?),\s+(.+?)\s*  # ...and values
            $/x) {
            return($_, $1, $2, $3, $4, $5);
        }
        else {
            croak "What was that? Bad uptime.";
        }
    }

    1;

##</code><code>##

    use Sys::uptime;

    my $uptime;
    tie $uptime, 'Sys::uptime';

    while (1) {
        print $uptime->uptime, "\n";
        print $uptime->users, "\n";
        print $uptime->load('one'), "\n";
        print $uptime->load('five'), "\n";
        print $uptime->load('fifteen'), "\n";
        print $uptime->as_string, "\n";

        sleep 3;
    }