my %hash = ( abca => {comment => 'a_b__ca', para1 => 1, para2 => 2}, abcb => {comment => 'a_b__cb', para1 => 7, para2 => 2}, abcc => {comment => 'a_b__cc', para1 => 4, para2 => 2}, abcd => {comment => 'a_b__cd', para1 => 9, para2 => 2}, );