sub foo {
        my $self     = shift;
        my $hash_ref = shift;

##</code><code>##

        # and so on...
    }

##</code><code>##

    my %hash = %{ shift };

##</code><code>##

    my %hash = %{ +shift };

##</code><code>##

    my %hash = %{ shift() };

##</code><code>##

    sub my_lc { lc +shift; }
    sub my_uc { uc +shift; }

##</code><code>##

    printf("#%02x%02x%02x %s\n", /(\d+)\s+(\d+)\s+(\d+)\s+(.*)/);

##</code><code>##

    #!/usr/bin/perl
    while (<>) {
        print "$_\n";
    }

##</code><code>##

    $ ./script a b c
    Can't open a: No such file or directory
    Can't open b: No such file or directory
    Can't open c: No such file or directory

##</code><code>##

    @ref = \($a, $b, $c);

##</code><code>##

    my %opt;
    GetOptions(\%opt, "size|s=i");