%mdata = (
         $pkey => {
         ABC  => trim_trailing($rec[1]),
         DESC => trim_trailing($rec[2]),
         UNIT => trim_trailing($rec[3]),
         LOC  => trim_trailing($rec[4])
         }
     )

##</code><code>##

$mdata{$pkey} = {
         ABC  => trim_trailing($rec[1]),
         DESC => trim_trailing($rec[2]),
         UNIT => trim_trailing($rec[3]),
         LOC  => trim_trailing($rec[4])
     };