Just because TIMTOWTDI, I put together a version using the qr// operator. I had guessed it would be more efficient than the /o version, but such is not the case:
use Benchmark;

push @lines, ((' ' x int rand 12) . (int rand 60000) . (' ' x int rand
+ 2)) for 1..10000;

@pattern_list = qw(12345 12346 20034 8787 31337 31338 54320 54321);
my $bad_ports = '\b(?:12345|12346|20034|8787|31337|31338|54320|54321)\
+b';

timethese( 100, {
            'qr' => 'with_qr',
            '/o' => 'with_o'
});

sub with_qr {
  foreach $pattern (@pattern_list) {
    my $re = qr/\b${pattern}\b/;
    foreach $line (@lines) {
      $line =~ /$re/;
    }
  }
}

sub with_o {
  my $found = 0;
  for(@lines){ 
    (/\b(?:$bad_ports)\b/o);
  }
}

[download]
with these results:
Benchmark: timing 100 iterations of /o, qr...
        /o:  7 wallclock secs ( 6.88 usr +  0.00 sys =  6.88 CPU) @ 14
+.53/s (n=100)
        qr: 20 wallclock secs (18.84 usr +  0.00 sys = 18.84 CPU) @  5
+.31/s (n=100)

[download]

Granted, this is a poor dataset, and mileage will probably vary for a real logfile.

In reply to RE: RE: I want to be a Perl Jedi by athomason
in thread I want to be a Perl Jedi by dru145

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.