the_0ne has asked for the wisdom of the Perl Monks concerning the following question:

Hi monks, haven't been on in awhile and haven't posted in an even longer while. Having trouble with a hash slice. Somehow I'm duplicating a slice of data, but have no idea how I'm doing it. Here's the relevant code... 
$to = "foo\@bar.com";
$subject = "New CDs now";
$file_name = "AAAAA.txt";
$from = "that\@person.com";
$last_dir = "Spam";

$spam->{$to} = $to;
$spam->{$to}->{$subject} = $subject;
$spam->{$to}->{$subject}->{$file_name} = $file_name;
$spam->{$to}->{$subject}->{$file_name}->{'path'} = $last_dir;
$spam->{$to}->{$subject}->{$file_name}->{'from'} = $from;

$to = "foo2\@bar.com";
$subject = "New CDs now";
$file_name = "BBBBB.txt";
$from = "that2\@person.com";
$last_dir = "Spam";

$spam->{$to} = $to;
$spam->{$to}->{$subject} = $subject;
$spam->{$to}->{$subject}->{$file_name} = $file_name;
$spam->{$to}->{$subject}->{$file_name}->{'path'} = $last_dir;
$spam->{$to}->{$subject}->{$file_name}->{'from'} = $from;

print "\n";
for my $email_slice (sort keys %{$spam}) {
  print "email_slice - $email_slice\n";

  for my $subject_slice (sort keys %{$email_slice}) {
    print "subject_slice - $subject_slice\n";

    for my $fn_slice (sort keys %{$subject_slice}) {
      print "fn_slice - $fn_slice\n";
    }
  }

  print "\n";
}

[download]
Sorry for the sloppy code, however, this comes from a very large script and just to figure this part out I wrote this code into a separate smaller script for debugging.
Most of you should be able to just paste this code into a vi session and run it, nothing special. Here's the output... 
email_slice - foo2@bar.com
subject_slice - New CDs now
fn_slice - AAAAA.txt
fn_slice - BBBBB.txt

email_slice - foo@bar.com
subject_slice - New CDs now
fn_slice - AAAAA.txt
fn_slice - BBBBB.txt

[download]
Notice how the fn_slice is duplicated? What I'm trying to get is... 
email_slice - foo2@bar.com
subject_slice - New CDs now
fn_slice - BBBBB.txt

email_slice - foo@bar.com
subject_slice - New CDs now
fn_slice - AAAAA.txt

[download]
Notice how the AAAAA.txt and BBBBB.txt are separated by their respective email addresses? I can not imagine how the fn_slice is getting duplicated? I think it has something to do with the $subject since it's the same, however, the email_slice should take care of that and separate it.

Thank you monks for your help, AGAIN! :)

Replies are listed 'Best First'.
Re: Why is part of slice duplicated?
by Abigail-II (Bishop) on May 28, 2002 at 17:18 UTC 
        $spam->{$to} = $to;
    $spam->{$to}->{$subject} = $subject;
    $spam->{$to}->{$subject}->{$file_name} = $file_name;
    $spam->{$to}->{$subject}->{$file_name}->{'path'} = $last_dir;
    $spam->{$to}->{$subject}->{$file_name}->{'from'} = $from;

    [download]

    You are doing some very fishy stuff here, which use strict; would not have allowed you to. First you set $spam->{$to} to $to, which is a string. But then, in the next line, with $spam->{$to}->{$subject}, you are treating it as a hashreference! And later on, you are doing the same trick with $subject and $file_name.

    You should use Data::Dumper and display the context of $spam. You will be surprised what it contains (or rather, what it doesn't contain).

    Remember, unless you know what you are doing, always use strict;.

    Abigail

[reply]
[d/l]
[select]
      Ok, I see what you mean. I added 'use strict;' and I get... 
      Can't use string ("foo@bar.com") as a HASH ref while "strict refs" in 
+use at ./test.pl line 14.

      [download]
      How can I fill the values of this structure then?... 
      # Data Structure.
#$spam_hash = {
# 'email@address.com' =>
#               {
#                'Subject1' => {
#                                cache_name1 => {
#                                                 path => 'path',
#                                                 from => 'from'
#                                               },
#                                cache_name2 => {
#                                                 path => 'path',
#                                                 from => 'from'
#                                               }
#                              },
#                'Subject2' => {
#                                cache_name1 => {
#                                                 path => 'path',
#                                                 from => 'from'
#                                               },
#                                cache_name2 => {
#                                                 path => 'path',
#                                                 from => 'from'
#                                               }
#               }
#};

      [download]
      Until I came across a duplicated $subject, this script was working perfectly. (I guess I was getting lucky.) I need to dynamically fill the subject and cache_names to becomes slices of the email address. I'm confused on how to change my structure to one that will be functional.
[reply]
[d/l]
[select]
        Well, I could give an answer and that will work, until you run into the situation you describe:
        Until I came across a duplicated $subject, this script was working perfectly.

        What do you want to do if you hit a duplicate subject?

        Abigail

[reply]
Re: Why is part of slice duplicated?
by danger (Priest) on May 28, 2002 at 17:16 UTC

    You are accidentally using symbolic references and do not have the structure you think you have --- using strict would have told you something was wrong right away. You can see a similar problem and discussion here.

[reply]

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