$_ = <DATA>;
chomp;
my @hdrs = split /,/;

my @recs;
while (<DATA>) {
  chomp;
  my %rec;
  @rec{@hdrs} = split /,/;
  push @recs, \%rec;
}

##</code><code>##

print "num1\tnum2\tnum3\n";
foreach (sort { $a->{num2} <=> $b->{num2} } @recs) {
  print "$_->{num1}\t$_->{num2}\t$_->{num3}\n";
}