#!/usr/bin/perl
#
use strict;
use warnings;

use feature qw{ say };

use Data::Dumper;

my $prompt = q{-> };
my $dePrompt
   = qq{\r}
   . q{ } x ( length( $prompt ) + 2 )
   . qq{\r};
my %RNA;

print qq{Please enter name, conc. and vol. (CTRL-D to finish):\n};
print $prompt;

while ( 1 )
{
    do { print $dePrompt; last; } if eof STDIN;
    chomp( my $line = <STDIN> );
    my( $name, $conc, $vol ) = split m{\s+}, $line;
    $RNA{ $name } = {
       conc => $conc,
       vol  => $vol,
       };
    print $prompt;
}

print Data::Dumper->Dumpxs( [ \ %RNA ], [ qw{ *RNA } ] );
say q{-} x 50;

foreach my $name ( sort keys %RNA )
{
    printf qq{%10s%8.2f%6d%8.2f%8.2f%8.2f\n},
       $name,
       $RNA{ $name }->{ conc },
       $RNA{ $name }->{ vol },
       $RNA{ $name }->{ conc } * $RNA{ $name }->{ vol },
       30 / $RNA{ $name }->{ conc },
       50 / $RNA{ $name }->{ conc };
}