When your subroutine is called, it is passed a list of values: key1, value1, ... keyn, valuen, title. One way to avoid this problem is to pass a reference to the hash instead of the contents of the hash:

printurls(\%URLS, $title);

...

my ($URLS, $title) = @_;

...

while(my($key, $value) = each %$URLS) {
  print "$key => $value\n";
}
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You can also use subroutine prototypes to transparently pass a hashref instead of a hash (I think).