$uniq{"$file"} = ({"suffix1"=>"$suff"}); 
$uniq{"$file"} = ({"suffix2"=>"$suff"});

##</code><code>##

# assign hashref with first key-value-pair
$uniq{"$file"} = {"suffix1" => "$suff"};
# add additional key-value-pair
$uniq{"$file"}->{"suffix2"} = "$suff";