#!/usr/bin/perl -w
use diagnostics;
while(1) {
  print "Command [(a)add, (s)how, (d)elete, (c)lear all, (l)list, (e)xit]? ";
  $cmd = <STDIN>;
  chomp $cmd;
  if ($cmd =~ /^a/i ) {
    print "name = ";
    $name = <STDIN>;
    chomp $name;
    print "phone = ";
    $phone = <STDIN>;
    chomp $phone;
    $addressbook{$name} = $phone;
  } elsif ($cmd =~ /^s/i ) {
    print "name = ";
    $name = <STDIN>;
    chomp $name;
    print "$name: $addressbook{$name}\n";
  } elsif ($cmd =~ /^d/i ) {
    print "name = ";
    $name = <STDIN>;
    chomp $name;
    delete $addressbook{$name};
  } elsif ($cmd =~ /^c/i ) {
    %addressbook = ();
  } elsif ($cmd =~ /^l/i ) {
    foreach $name (sort keys %addressbook) {
      print "$name: $addressbook{$name}\n";
    }
  } elsif ($cmd =~ /^e/i ) {
    print "Bye!\n";
    exit 0;
  }
}