% perldoc -tq unique 
Found in /usr/local/lib/perl5/5.00502/pod/perlfaq4.pod
  How can I extract just the unique elements of an array?

            There are several possible ways, depending on whether
            the array is ordered and whether you wish to preserve
            the ordering.

    a) If @in is sorted, and you want @out to be sorted:
    (this assumes all true values in the array)
                    $prev = 'nonesuch';
                    @out = grep($_ ne $prev && ($prev = $_), @in);

                This is nice in that it doesn't use much extra
                memory, simulating uniq(1)'s behavior of removing
                only adjacent duplicates. It's less nice in that it
                won't work with false values like undef, 0, or "";
                "0 but true" is ok, though.

    b) If you don't know whether @in is sorted:
                    undef %saw;
                    @out = grep(!$saw{$_}++, @in);

[download]
There's more, but I won't paste it all. Look at the Perl documentation, perlfaq4. This is available in many places, such as http://www.perldoc.com/.

$_="goto+F.print+chop;\n=yhpaj";F1:eval

In reply to Re: extract uniques and sort by japhy
in thread extract uniques and sort by ybiC

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.