our ($x,$y) = "Hello, World!";
*y = \substr $x, 7, 5;  # alias via glob

$y = "substring";
print "<$x>\n";  # prints <Hello, substring!>

$y = "Perl";
print "<$x>\n";  # prints <Hello, Perl!>

$x = "Magic, cool stuff!";
print "<$y>\n";  # prints <cool>