#! /usr/bin/perl
use strict;

my %son_father;
my $choice;
my $name1;
my $add_dad;

%son_father = (Jeff => "Doug",
               Thomas => "Evan",
               Robert => "Jason",
               Bruce => "Richard",
               Clark => "Jon")  ;
               
my $menu = <<MENU;

         SON_FATHER Hash Operations

a- Add a son-father pair
d- Delete a son-father pair
e- exit the program
g- Get a father
o- Output the hash neatly
r- Replace a father
x- get a grand father
MENU

while (1) {
  # display the menu
  print $menu, "\n\n";

  # get the user choice
  print "Make your choice: ";
  chomp($choice = lc <STDIN>);

  # fulfill the user request
  if ($choice eq 'a'){
    print "Enter a male name: ";
    chomp ($name1 =  <STDIN>);
    if (exists $son_father{$name1}) {
          print "Duplicate name -- try again!\n";
          next;
    }
    print "Add a father: ";
    chomp ($add_dad =  <STDIN>);
    $son_father{$name1} = $add_dad;
    print "Added\n";
    next; # <<<<< added
  }

  if ($choice eq 'd') {
    print "Enter a male name: ";
    chomp ($name1 =  <STDIN>);
    if (exists $son_father{$name1}) {
          delete $son_father{$name1};
          print "Deleted.\n";
    } else {
             print "Sorry, couldn't find '$name1' -- try again later!";
    }
    next;
  }


  if ($choice eq 'o') {
     print "$_\t=> $son_father{$_}\n" for sort keys %son_father;
     next;
  }

  if ($choice eq 'e') {
    print "Come back again -- goodbye!";
    exit;  
  }else {
    print "Invalid choice, TRY AGAIN!\n";
  }
}