Select Code to Download

while ($_ = substr($foo,$i++,1)){
    if (++$_**2 == 0) {
...
        last;
    } 
}

my $i = 0;
while (local $_ = substr($foo,$i++,1)){
...
        last;
    } 
}

while (++substr($foo,$i++,1) != 0){}