foreach(keys %users) {
       my %user=$_;
       [...]
   }

##</code><code>##

   foreach my $username (keys %users) {
      #my $pw=getpwnam($users{$username}{uname});
      # actually it's simpler, you already have the name...
      my $pw=getpwnam($username);
      my $homedir=$pw->dir;
   }