My first Perl module...

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

I'm a long time reader, but first time seeker. I consider myself at perhaps an intermediate level. Anyway, here's my problem:

The relevant portions of code are as follows:

sub new {
        my $self = {};
        $self->{_ldap} =  Net::LDAP->new($LDAP_SERVER);
        bless $self;
        return $self;
}
[download]

Which initializes my module...it's purpose is to make administering an ldap-aware mail server easier in my company.

sub alias_add_entry {
        my $self = shift;
        my $alias = shift;
        my $user = shift;
        my $result;

        die "Not enough args to alias_add_entry() $@" if not defined (
+$alias and $user);

        $result = $self{"_ldap"}->modify (
                dn => "cn=$alias,ou=Aliases,dc=mydomain,dc=com",
                add => { rfc822mailmember => $user }
                );
        return $result;
}
[download]

This is the first of many subs which returns the error: Global symbol "%self" requires explicit package name at MyModule.pm line xxx, where xxx references the $result = line.
The thing is, this sub works fine:

sub authenticate {
        my $self = shift;
        my $pw = shift;
        my $user = shift;

        die "Not enough args to authenticate() $@" if not defined $pw;
        $user = "Manager" if ($user eq "");
        my $result = $self->{"_ldap"}->bind (
                dn        => "cn=$user, dc=sigmatel, dc=com",
                password  => $pw
            );
        return $result;
}
[download]

Any ideas?

Comment on My first Perl module... Select or Download Code

Replies are listed 'Best First'.
Re: My first Perl module... by snax (Hermit) on Nov 17, 2000 at 13:57 UTC
In the sub that works you use `$self->{}` [download] explicitly dereferencing the `$self` reference. In the sub that doesn't work you use `$self{}` [download] which implies that `$self` is a hash itself and not a reference -- thus making your `use strict;` complain about an undefined global hash called `%self`. As a side note I'd suggest dropping the double quotes in your hash keys -- they're not necessary and they force interpolatin where none is necessary (even if you needed interpolation you wouldn't need quotes there).	[reply] [d/l] [select]
Re: Re: My first Perl module... by Anonymous Monk on Nov 17, 2000 at 14:24 UTC
Hmm, so is defining `%self` globally the answer? It doesn't seem like it should be to me, but I'll of course defer to your judgement. :)	[reply] [d/l]
Re: Re: Re: My first Perl module... by t0mas (Priest) on Nov 17, 2000 at 14:33 UTC
No, defining %self is not the answer (and I don't think snax said it was). You should use a valid syntax for references, like $self->{"_ldap"}, to refer to the anonymous hash that $self refers to. /brother t0mas	[reply]
Re: Re: Re: My first Perl module... by snax (Hermit) on Nov 17, 2000 at 16:50 UTC
t0mas is correct -- I don't suggest that you declare `%self` globally, especially since it really won't do what you want it to do :) Check out perlman:perlref for more details on using references, and poking through perlman:perlobj and/or perlman:perltoot is probably a good idea, too.	[reply]
Re: Re: Re: My first Perl module... by Fastolfe (Vicar) on Nov 17, 2000 at 20:14 UTC
$hash{key} refers to the 'key' element of the hash called %hash. $hash->{key} refers to the 'key' element of the hash referred to in the reference $hash. $hash has nothing to do with %hash. Check out perlref and other documentation mentioned by others.	[reply]
Re: My first Perl module... by t0mas (Priest) on Nov 17, 2000 at 13:55 UTC
You'll need to do something like $result = $self->{"_ldap"}->modify() (as you do in authenticate with the bind call) Refer to perldoc perlref for more goodies aboute refs. /brother t0mas	[reply]