Perl shift operator simple question

Question

What\'s the purpose of the following two lines of perl??

my $host = shift || \'localhost\';
my $port = shift || 200;

That should return loc

Answer 1

If no argument is provided, shift will shift @ARGV outside a subroutine and @_ inside a subroutine – that is the argument array passed to either the main program or the subroutine.

In your case, $host is assigned the first element of @ARGV (or @_, if the code is inside a sub) or 'localhost', if the element is false.

This is a very common Perl idiom.