Comments

# Single line comment
=head1 Here There
	Be Pods!
=cut

Strings

q/foo bar baz/;
q awhy not ?a;
qw(foo bar baz) q{foo bar baz}
q[foo bar baz] qq<foo bar baz>
"foo bar baz" 'foo bar baz' `foo bar baz`

Regex

m/foo/ s/foo/bar/
m zfooz s zfoozbarz
qr(foo) m{foo} s(foo)(bar) s{foo}{bar}
m[foo] m<foo> tr[foo][bar] s<foo><bar>
/foo/i

Variables

${^POSTMATCH}
$^V
$element_count = scalar(@whatever);
keys(%users) = 1000;
$1, $_, %!;

Numbers

12345
12345.67
.23E-10 # a very small number
3.14_15_92 # a very important number
4_294_967_296 # underscore for legibility
0xff # hex
0xdead_beef # more hex
0377 # octal (only numbers, begins with 0)
0b011011 # binary

Full example

sub read_config_file {
  my ($class, $filename) = @_;

  unless (defined $filename) {
    my $home  = File::HomeDir->my_home || '.';
    $filename = File::Spec->catfile($home, '.pause');

    return {} unless -e $filename and -r _;
  }

  my %conf;
  if ( eval { require Config::Identity } ) {
    %conf = Config::Identity->load($filename);
    $conf{user} = delete $conf{username} unless $conf{user};
  }
  else { # Process .pause manually
    open my $pauserc, '<', $filename
      or die "can't open $filename for reading: $!";

    while (<$pauserc>) {
      chomp;
      next unless $_ and $_ !~ /^\s*#/;

      my ($k, $v) = /^\s*(\w+)\s+(.+)$/;
      Carp::croak "multiple enties for $k" if $conf{$k};
      $conf{$k} = $v;
    }
  }

  return \%conf;
}