grammar SarDisk
{
    rule TOP
    {
        <time> <devname> .*$
    }

    regex time
    {
        |(\d+) ':' (\d+) ':' (\d+) \s+ ('AM')
        |(\d+) ':' (\d+) ':' (\d+) \s+ ('PM')
        |(\d+) ':' (\d+) ':' (\d+)
    }

    regex devname
    {
        "dev" \d+ '-' \d+
    }
}

class SarDiskActions
{
    method time ($/)
    {
        make self.convert-AM($/) if $/[3] eq 'AM';
        make self.convert-PM($/) if $/[3] eq 'PM';
    }

    method convert-AM ($hour)
    {
        my @time = $hour.split(':');
        @time[0] = '00' if @time[0] == 12;
        pop @time;
        return @time.join(':');
    }
method convert-PM ($hour)
    {
        my @time = $hour.split(':');
        @time[0] += 12 if @time[0] != 12;
        pop @time;
        return @time.join(':');
    }
}

for './sar30'.IO.lines -> $line
{
    my $result = SarDisk.parse($line, :actions(SarDiskActions));
    put $result<time>.made ~ ' ' ~ $result<devname> if $result.so;
}