Thank you. I did as you suggested, and it seems like my split has now somehow broke: I get the error "Use of unitialized value in concatenation (.) or string at tree.pl line 36, <DATA> line 1 (for all the <DATA> lines).

I copied and pasted the code from perlmonks onto a different computer; that may be related.

I thought perhaps my vim expandtabs option on this machine was involved, but I retyped the DATA using ^V. This code

# key: parent 
# val: list of immediate children
sub load_hashes{
    my ($child, $par);
    while(<DATA>){
        chomp;
        ($child, $par) = split /"\t"/;
#push @{$immed_child{$par}}, $child;
        print "ch: $child, par: $par\n";
    }
}

[download]
prints the entire table row as the value of $child, and no value for $par. For example:

ch: jumprope exercise_device, par:

this explains the unitialized value in the string. Is there an obvious mistake in my split that has somehow occurred in the copying of the code from perlmonks onto a new machine?

In reply to Re: 2: recursive difficulty by jjohhn
in thread recursive difficulty by jjohhn

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