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| Using Perl-5.8.2 and the following (INN) script to insert values into a
new DB file, it appears that Perl/NDBM_File is grabbing some POD
documentation from somewhere and inserting it into the DB file?! This does
NOT happen with Perl-5.6.1.
#!/usr/bin/perl
use Fcntl;
use NDBM_File;
tie (%db, 'NDBM_File', 'newsusers', O_RDWR | O_CREAT, 0640)
or die "Cannot open newsusers: $!\n";
$| = 1;
print "Username: ";
my $user = <STDIN>;
chomp $user;
print "Password: ";
my $passwd = <STDIN>;
chomp $passwd;
my @alphabet = ('.', '/', 0..9, 'A'..'Z', 'a'..'z');
my $salt = join '', @alphabet[rand 64, rand 64];
$db{$user} = crypt ($passwd, $salt);
untie %db;
exit;
====== sample "POD garbage" plus script data in DB file ==================
strings newsusers.db
orage = bless [{}, @_], $class;
warn "New ReportHash created, stored in $storage.\n";
$storage;
sub STORE {
warn "Storing data with key $_[1] at $_[0].\n";
$_[0][0]{$_[1]} = $_[2]
The default C<TIEHASH> method stores "extra" arguments to tie() starting
from offset 1 in the array referenced by C<tied(%tiedhash)>; this is the
same storage algorithm as in TIEHASH subroutine above. Hence, a typical
package inheriting from B<Tie::ExtraHash> does not need to overwrite this
method.
=head1 C<UNTIE> and C<DESTROY>
The methods C<UNTIE> and C<DESTROY> are not defined in B<Tie::Hash>,
B<Tie::StdHash>, or B<Tie::ExtraHash>. Tied hashes do not require
presense of these methods, but if defined, the methods will be called in
proper time, see L<perltie>.
If needed, these methods should be defined by the package inheriting from
B<Tie::Hash>, B<Tie::StdHash>, or B<Tie::ExtraHash>.
=head1 MORE INFORMATION
The packages relating to various DBM-related implementations (F<DB_File>,
F<NDBM_File>, etc.) show examples of general tied hashes, as does the
L<Config> module. While these do not utilize B<Tie::Hash>, they serve as
good working examples.
=cut
use Carp;
use warnings::register;
sub new {
my $pkg = shift;
$pkg->TIEHASH(@_);
# Grandfather "new"
sub TIEHASH {
my $pkg = shift;
if (defined &{"${pkg}::new"}) {
warnings::warnif("WARNING: calling ${pkg}->new since ${pkg}->TIEHASH is missing");
$pkg->new(@_);
}
else {
croak "$pkg doesn't define a TIEHASH method";
}
sub EXISTS {
my $pkg = ref $_[0];
croak "$pkg doesn't define an EXISTS method";
sub CLEAR {
my $self = shift;
my $key = $self->FIRSTKEY(@_);
my @keys;
while (defined $key) {
push @keys, $key;
$key = $self->NEXTKEY(@_, $key);
}
foreach $key (@keys) {
$self->DELETE(@_, $key);
}
# The Tie::StdHash package implements standard perl hash behaviour.
# It exists to act as a base class for classes which only wish to
# alter some parts of their behaviour.
package Tie::StdHash;
# @ISA = qw(Tie::Hash); # would inherit new() only
sub TIEHASH { bless {}, $_[0] }
sub STORE { $_[0]->{$_[1]} = $_[2] }
sub FETCH { $_[0]->{$_[1]} }
sub FIRSTKEY { my $a = scalar keys %{$_[0]}; each %{$_[0]} }
sub NEXTKEY { each %{$_[0]} }
sub EXISTS { exists $_[0]->{$_[1]} }
sub DELETE { delete $_[0]->{$_[1]} }
sub CLEAR { %{$_[0]} = () }
package Tie::ExtraHash;
sub TIEHASH { my $p = shift; bless [{}, @_], $p }
sub STORE { $_[0][0]{$_[1]} = $_[2] }
sub FETCH { $_[0][0]{$_[1]} }
sub FIRSTKEY { my $a = scalar keys %{$_[0][0]}; each %{$_[0][0]} }
sub NEXTKEY { each %{$_[0][0]} }
sub EXISTS { exists $_[0][0]->{$_[1]} }
sub DELETE { delete $_[0][0]->{$_[1]} }
sub CLEAR { %{$_[0][0]} = () }
Note that you cannot use tags in @EXPORT or @EXPORT_OK.
Names in EXPORT_TAGS must also appear in @EXPORT or @EXPORT_OK.
An application using Module can say something like:
use Module qw(:DEFAULT :T2 !B3 A3);
Other examples include:
use Socket qw(!/^[AP]F_/ !SOMAXCONN !SOL_SOCKET);
use POSIX qw(:errno_h :termios_h !TCSADRAIN !/^EXIT/);
Remember that most patterns (using //) will need to be anchored
with a leading ^, e.g., C</^EXIT/> rather than C</EXIT/>.
You can say C<BEGIN { $Exporter::Verbose=1 }> to see how the
specifications are being processed and what is actually being imported
into modules.
=head2 Exporting without using Exporter's import method
Exporter has a special method, 'export_to_level' which is used in situations
where you can't directly call Exporter's import method. The export_to_level
method looks like:
MyPackage->export_to_level($where_to_export, $package, @what_to_export);
where $where_to_export is an integer telling how far up the calling stack
to export your symbols, and @what_to_export is an array telling what
symbols *to* export (usually this is @_). The $package argument is
currently unused.
For example, suppose that you have a module, A, which already has an
import function:
package A[gen.passwd script data]
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