Dispite that many has pointed out that

    while (my $line = <DATA>) { ... }
    while (defined (my $line = <DATA>)) { ... }
[download]

    while (<DATA>) { ... }
[download]

    while (my $line = <DATA>) { ... }
[download]

If put in a subroutine this innocent little bug cause a serious headache while trying to find out why $_ all of a sudden is undefined.

ihb