hash of hashes of lists!!!

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

i am developing a web management system and am working with a hash of hashes of lists as so:

$hashoffiles->{$streamID}->{$filename} = (modsize, group, user etc...)
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I am sure that i am constructing them correctly but when i try to loop though the second key i get the following error. For some reason it does not see $streamID as a hash but as a single variable

Can't use string ("1") as a HASH ref while "strict refs" in use at E:\
+Inetpub\cgi-bin\wms.pl line 176.
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My construction code is

foreach my $dir (@dirList) 
{
    if(! -d $dir) 
    {
        push @failDir, ($dir);
        next;
    }       
       find { wanted => sub {
       
    #the @fileInfo array is created using the stat function but is irr
+elevant for perlmonks
    my @fileInfo = ($mode, $user, $group, $size, $mtime, $type, $filen
+ame, $filepath);
          
       #$hashOfStreams has two keys: 1 and 8
   
    #Create a hash of files from source dir for each stream
    foreach my $key (keys %$hashOfStreams)
    {
        #ie $hashOfFiles->{'1'}->{'E:/mame.txt} = [ '$mode', '$user', 
+'$group'.. ];
        #ie $hashOfFiles->{'8'}->{'E:/mame.txt} = [ '$mode', '$user', 
+'$group'.. ];
        $hashOfFiles->{$key}->{$File::Find::name} = [ @fileInfo ];
        
        #the following Debug code prints all vars correctly
        print "$key $File::Find::name $mode, $user, $group, $size, $mt
+ime, $type, $filename, $filepath<br>";
    }
    
    }, follow => 0}, "$dir";
}
[download]

my looping code is as follows


foreach $key (sort keys %$hashOfFiles) 
{
    #FAILS HERE -  ERROR SAYS THAT $key is not a hash but a string
    foreach my $file (sort keys %$key) 
    {
           my ($mode2, $user2, $group2, $size2, $mtime2, $filename, $f
+ilepath) = @{$hashOfFiles->{$key}->{$file}};
        print "$file - $filename, $filepath, $mode2 $user2, $group2, $
+size2, $mtime2<br>";
       }
}
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Can anyone who has dealt with complex vars see the problem? I have been looking for hours but cannot see it? Is it possible to create vars as complex as this?

Costas

Comment on hash of hashes of lists!!! Select or Download Code

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Re: hash of hashes of lists!!! by Juerd (Abbot) on Apr 05, 2002 at 14:26 UTC
i am developing a web management system and am working with a hash of hashes of lists as so: $hashoffiles->{$streamID}->{$filename} = (modsize, group, user etc...) I am sure that i am constructing them correctly but when i try to loop though the second key i get the following error. Be less sure, or update your example code. $foo->{bar}->{baz} is a scalar, and when you assign to a scalar, there is scalar context. In scalar context, a list evaluates to its last element. You can't have a hash of hashes of lists, but you can have a hash of hashes of arrays. A list is always temporary, for storing, you need an array. However, in your code you use square brackets, and do it the right way. I don't see the problem, and it would be a LOT easier for us if you added a note so we know which line is line 176. In the meanwhile, try dumping your data structure using Data::Dumper to see if it contains what you want it to. U28geW91IGNhbiBhbGwgcm90MTMgY W5kIHBhY2soKS4gQnV0IGRvIHlvdS ByZWNvZ25pc2UgQmFzZTY0IHdoZW4 geW91IHNlZSBpdD8gIC0tIEp1ZXJk	[reply]
Re: hash of hashes of lists!!! by strat (Canon) on Apr 05, 2002 at 14:54 UTC
Better try something like: `foreach my $key (sort keys %$hashOfFiles) { foreach my $file (sort keys %{ $hashOfFiles->{$key} }) # foreach my $file (sort keys %$key) { my ($mode2, $user2, $group2, $size2, $mtime2, $filename, $filepath +) = @{ $hashOfFiles->{$key}->{$file} }; #...` [download] Btw: very often it is a good idea checking more complicated datastructures with Data::Dump or Data::Dumper (especially if you are not sure if you are constructing them in the right way). Best regards, perl -le "s==F=e=>y~\martinF~stronat~=>s~[^\w]~~g=>chop,print"	[reply] [d/l]
Don't use the key, use the hash ref... by RMGir (Prior) on Apr 05, 2002 at 14:30 UTC
You're using the key instead of the hash entry as your reference in your keys statement... `foreach $key (sort keys %$hashOfFiles) { #foreach my $file (sort keys %$key) foreach my $file (sort keys %{$hashOfFiles->{$key}})` [download] -- Mike Edit: Was using %() instead of %{} to wrap the hash reference. :(	[reply] [d/l]
Re: hash of hashes of lists!!! by costas (Scribe) on Apr 05, 2002 at 14:34 UTC
line 176 is `foreach $key (sort keys %$hashOfFiles) { #LINE 176 foreach my $file (sort keys %$key) { my ($mode2, $user2, $group2, $size2, $mtime2, $filename, $f +ilepath) = @{$hashOfFiles->{$key}->{$file}}; print "$file - $filename, $filepath, $mode2 $user2, $group2, $ +size2, $mtime2<br>"; } }` [download] I am using arrays and not lists. Sorry for not making it clear. I am updating my code from a previous version so i am sure that the array works fine. You said: $foo->{bar}->{baz} The failure is recognising 'bar' as a scalar rather than a hash and is (i think) nothing to do with 'baz' being a scalar or array.	[reply] [d/l]
Re: Re: hash of hashes of lists!!! by Juerd (Abbot) on Apr 05, 2002 at 15:15 UTC
The failure is recognising 'bar' as a scalar rather than a hash and is (i think) nothing to do with 'baz' being a scalar or array. bar is an unquoted string, baz is an unquoted string. $foo->{bar} is a scalar, holding a hash reference. %{ $foo->{bar} } is the hash to which $foo->{bar} is refering. $foo->{bar}->{baz} is a scalar. U28geW91IGNhbiBhbGwgcm90MTMgY W5kIHBhY2soKS4gQnV0IGRvIHlvdS ByZWNvZ25pc2UgQmFzZTY0IHdoZW4 geW91IHNlZSBpdD8gIC0tIEp1ZXJk	[reply]
Re: hash of hashes of lists!!! by tachyon (Chancellor) on Apr 06, 2002 at 01:44 UTC
`use Data::Dumper; # assemble you data structure $structure = { 1 => { 1 => [1,2,3], 2 => [2,4,6] }, 2 => { 1 => [2,4,6], 2 => [4,8,12] } }; print Dumper($structure); my ( $one, $two, $three) = @{$structure->{'1'}->{'1'}}; print "$one, $two, $three\n";` [download] cheers tachyon s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print	[reply] [d/l]