Data commit

Task/Singleton/Perl/singleton.pl

@@ -0,0 +1,29 @@
+package Singleton;
+use strict;
+use warnings;
+
+my $Instance;
+
+sub new {
+    my $class = shift;
+    $Instance ||= bless {}, $class; # initialised once only
+}
+
+sub name {
+    my $self = shift;
+    $self->{name};
+}
+
+sub set_name {
+    my ($self, $name) = @_;
+    $self->{name} = $name;
+}
+
+package main;
+
+my $s1 = Singleton->new;
+$s1->set_name('Bob');
+printf "name: %s, ref: %s\n", $s1->name, $s1;
+
+my $s2 = Singleton->new;
+printf "name: %s, ref: %s\n", $s2->name, $s2;