I am getting following error in perl. "Not a HASH reference at tocsvfd.pl line 31". the code.Below is the code through where I am getting this error. How can I correct it? The last line of the code is line 32 
my $src = dir("C:/Perl/pubmed/Prasuna/DM/Database/Drugbank/Split");

#Check files in folder
my @txt_files = $src->children;

for my $txt_file ( @txt_files ) {
    my $in = $txt_file->openr;
    my $parser = new XML::Simple;
    my $tree = $parser->XMLin($in);

    $alldrug = $tree->{drug};
    #print pp($alldrug);
    @allkeys = keys % $alldrug;

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In reply to Not a HASH reference by pdahal

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