Hello Monks,

I find a natural intersection between skywatching and programming, because I'm always curious about when beautiful events happen *exactly*. So it is that I've been watching Venus and Jupiter close the distance on each other, awaiting their confluence some time in early July. I'd like to use perl to tell me where and when this "occultation" begins and ends. The site I'll draw my data from is given as a lexical variable in this script:

#!/usr/bin/perl -w
use strict;
use 5.010;
use HTML::Treebuilder;

#use HTML::TreeBuilder 5 -weak; # Ensure weak references in use

my $site = "https://www.fourmilab.ch/yoursky/";
my $tree = HTML::TreeBuilder->new_from_url($site);           
$tree->parse_file($site);
print "Hey, here's a dump of the parse tree of $site:\n";
$tree->dump;    # a method we inherit from HTML::Element
#print "And here it is, bizarrely rerendered as HTML:\n", $tree->as_HT
+ML, "\n";
# Now that we're done with it, we must destroy it.
$tree = $tree->delete;    # Not required with weak references
__END__

[download]

There's 2 things that I need to make happen in order to bring some numbers to bear on this endeavor. 1) I need to follow the link for "nearby city" and set it to "Portland, OR" and 2) I need to capture the ephemeris, which comes across as a table.

Another question at the get-go: what makes a weak reference different and why might I want that over what I have?

Thanks for your comment,

In reply to Using HTML::Treebuilder effectively to capture data by Aldebaran

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