#!/usr/bin/perl -w
use strict;

print " Welcome to your own Personal Address Book!\n";

my $explain_text = 
" Command are:
 add     Add An Entry
 del     Delete An Entry
 prn     Print all Entries
 end     End Program
 quit    Also Ends program

";

my $short_prompt = "add,del,prn or quit: "; 
my $input;
my %directory=();

print $explain_text;  #don't keep printing this long stuff 

while ( ($input=prompt_for_input($short_prompt)), $input !~ /\s*end|quit\s*$/i)
{
   next if $input =~ /^\s*$/;  # re-prompt on blank lines
                               # this is not an error!
   
   if ($input =~ /^\s*add\s*$/)
   {
       add_entry();  
   }
   elsif ($input =~ /^\s*del\s*$/)
   {
       delete_entry();  
   }
   elsif ($input =~ /^\s*prn\s*$/)
   {
       print_directory();
   }
   else
   {
      print "illegal command!\n";
   }
}

sub prompt_for_input
{
   my $message = shift;
   
   print $message;
   my $input = <>;
   
   $input =~ s/^\s*//; # no leading spaces
   $input =~ s/\s*$//; # no trailing spaces

   return $input;
}

sub add_entry
{
   my $name = prompt_for_input ("Enter the Name you would like to add: ");
   my $address = prompt_for_input ("Enter an Address for $name: ");
      
   $directory{$name} = $address;    
}

sub delete_entry
{
   print "some code to get name to delete goes here\n";
}

sub print_directory
{
   print "These are the people in your address book:\n";
   
   printf "%-15s %s\n", "Name", "Address";
   foreach my $who (sort keys %directory)
   {
       printf "%-15s %s\n", $who, $directory{$who};
   }
   print "\n";
}