...
$db = "textfile.txt";
open(DATA, $db) or die "cant open: $!\n";
@dat = <DATA>;
close(DATA);
foreach $line (@dat)
{
    ...
}

##</code><code>##

...
$db = "textfile.txt";
open(DATA, $db) || die "cant open: $!\n";
foreach $line (<DATA>)
{
    ...
}
close(DATA);