my ($ptid, $total, $used, $avail, $pct, $mp) = $element =~
       m!^(/dev/\S+)           # which partition $ptid
           \s+([\d.]+[MGK])    # total size of parition $total
           \s+([\d.]+[MGK])    # used space $used
           \s+([\d.]+[MGK])    # available space $avail
           \s+(\d{1,3})%       # percent usage $pct
           \s+(.*)$!x;         # mounting point $mp