$ cat pm_1202351.pl
#! /usr/bin/perl
use strict;

my %son_father;
my $choice;
my $name1;
my $name2;
my $name3;
my $name4;
my $newname;
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 (my $name1 = ucfirst lc <STDIN>);
  }
  if (exists $son_father{$name1}) {        #46
    print "Duplicate name -- try again!\n";
  } else {
    print "Add a father: ";
    chomp (my $add_dad = ucfirst lc <STDIN>);
    $son_father{$name1} = {$add_dad};
    next;
  }

  if ($choice eq 'd') {
    print "Enter a male name: ";
    chomp (my $name2 = ucfirst lc <STDIN>);
  }
  if (exists $son_father{$name2}) {        #59
    delete $son_father{$name2};
  } else {
    print "Sorry, couldn't find you -- try again later!";
    next;
  }

  if ($choice eq 'e') {
    print "Come back again -- goodbye!";
    last;
    next;
  }

  if ($choice eq 'g'){
    print "Enter a son's name: ";
    chomp (my $name4 = ucfirst lc <STDIN>);
  }
  if (exists $son_father{$name4}) {        #76
    print "$son_father{$name4}\n";
    next;
  }

  if ($choice eq 'o'){
    my ($key, $value);
    foreach $value (sort keys %son_father){
      print "$value\t$son_father{$value}\n";
      next;
    }

  }
  if ($choice eq 'r'){
    print "Enter a male name: ";
    chomp (my $name3 = ucfirst lc <STDIN>);
    if (exists $son_father{$name3}) {
      print "Enter a new father name: ";
      chomp ($newname = ucfirst lc <STDIN>);
      $son_father{$name3} = {$newname};
    } else {
      print "Sorry, couldn't find you -- try again later!";
      next;
    }
  }
  if ($choice ne 'a', $choice ne 'r', $choice ne 'o', $choice ne 'd', $choice ne 'e', $choice ne 'g') {
    print "Invalid choice, TRY AGAIN!\n";
    next;
  }
}