@foo = (1,2,3);
process_array(@foo);

sub process_array {
    # the special @_ variable now holds (1,2,3), NOT (@foo)
    $var1 = shift;    # $var1 will only get '1'.
    $var2 = shift;    # $var2 will only get '2'.
    $var3 = shift;    # $var3 will only get '3'.

}

##</code><code>##

sub process_array {
    @args = @_;

}

##</code><code>##

sub process_array {
    $args = \@_;

}