how do I determine if any of those links match the leading one I used to start the fetch, and subsequent links found on pages followed from there?

Strip any anchors off immediately upon capturing the link. Keep a single hash with all of the seen URLs. When you start, add your root URL to the hash.

If I blindly just push the new elements onto the hash, I'll overwrite any existing keys (and values) which have the same key, which might not be good for efficiency.

You won't overwrite the keys. Perl will see that the key exists and simply change the value. You can use exists() if you want to, but it isn't really necessary and I wouldn't do it.

-sauoq
"My two cents aren't worth a dime.";

In reply to Re: Re: Re: Pushing unique items onto an array by sauoq
in thread Pushing unique items onto an array by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.