Select Code to Download

# Code using iterator:
    while(  <INPUT>  ) {
...
        \*INPUT,
        sub { process_line($_) }
    );

    # A merge sort:
    my $r1= <$i1>;
...
        $r2= <$i2>   if  0 le $cmp;
    }
    # ...

    File::ProcessLines(
        $i1,
...
            );
        }
    );