in reply to Re^2: Not a HASH reference error
in thread Not a HASH reference error

The significance is that line 56 is the earliest point at which Perl discovers there's a problem with line 55.

Line 55 grabs the value of a hash key. In this case, that hash key does not contain a hash reference (maybe doesn't exist at all). But this is no problem for Perl. If the key doesn't exist, then the value is undef. If it exists but isn't a hash reference, it still causes no problem for line 55. In line 56 you then try to dereference that value as though it were a hash. If the value was undef, that clearly cannot be dereferenced. And if the value was defined, but wasn't a hash ref, you also cannot dereference it as a hash. So at this point Perl has no idea what to do, and complains.


Dave

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Re^4: Not a HASH reference error
by briandanderson1977 (Novice) on Feb 24, 2016 at 20:35 UTC

    AHHH okay, thank you for the information, that was very valuable. Here is what I found for $hashref within the script. It only shows up on line 49 and line 55. 

    47 # OUTPUT returns true/false that the specified db2 configuration fi
+le could be processed appropriately     for the given action.
 48         my $log_pre = whatsub();
 49         my ($action,$hashref,@type_order) = @_ or (warn "$log_pre 
+Invalid arguments" and return 0);
 50
 51         # Iterate over the configuration types listed in @type_ord
+er
 52         foreach my $type (@type_order) {
 53                 print "$log_pre running $action for $type entries\
+n";
 54                 # Iterate over all items of that type
 55                 my $type_hash = $hashref->{$type};                
+      #shortcut to smaller hash
 56                 foreach my $item (keys %{$type_hash}) {
 57                         print "$log_pre running $action for $type 
+$item\n";
 58                         my $item_hash = $type_hash->{$item};      
+      #shortcut to smaller hash
 59                         #Add values for type and action into the h
+ash
 60                         $item_hash->{'name'} = $item;
 61                         $item_hash->{'type'} = $type;
 62                         $item_hash->{'action'} = $action;
 63                         #print Dumper($item_hash);

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[d/l]

      After line 53, add this:

      die "$type doesn't exist in %{\$hashref}" or isnt a hash ref unless exists $hashref->{$type} && ref $hashref->{$type} eq 'HASH';

      The point is that the caller is passing $hashref, and @type_order. But one (or more) of the types in @type_order is either not a key in %{$hashref}, or the value of that key is itself not a hashref.


      Dave

[reply]
[d/l]

        I tried adding that line that you asked me to add, but now it complains of having a configuration or compilation error. Here is what the perl script looks like now 

                # Iterate over the configuration types listed in @type_order
        foreach my $type (@type_order) {
                print "$log_pre running $action for $type entries\n";
                # Iterate over all items of that type
                my $type_hash = $hashref->{$type};                    
+  #shortcut to smaller hash
                foreach my $item (keys %{$type_hash}) {
                        print "$log_pre running $action for $type $ite
+m\n";
die "$type doesn't exist in %{\$hashref}" or isnt a hash ref unless ex
+ists $hashref->{$type} && ref $hashref->{$type} eq 'HASH';
                        my $item_hash = $type_hash->{$item};          
+  #shortcut to smaller hash
                        #Add values for type and action into the hash
                        $item_hash->{'name'} = $item;
                        $item_hash->{'type'} = $type;
                        $item_hash->{'action'} = $action;
                        #print Dumper($item_hash);
                        #execute action for the individual configurati
+on
                        unless (db2_mgmt_cat(\%{$item_hash})) {

        [download]
        Please let me know what you think. I'm still getting the pseudo-hash error, I'm wondering if that has something to do with it. THANK YOU!!!

[reply]
[d/l]

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