AutoNav now will select posts by category, tag, or author

Posted on September 1, 2010 by bill

My AutoNav Graphical Navigation and Gallery Plugin now will let you select posts not just by postid, but also by category, tag, or author:

 postid="category:17"    posts in a numeric category or categories
 postid="category:-17"   posts *not* in a numeric category
 postid="category:cakes" posts by category name
 postid="tag:37,38,53"   posts with numerically specified tag(s)
 postid="tag:chocolate"  posts by tag name
 postid="author:27"      posts by a specific author by ID
 postid="author:Todd"    posts by author name

Categories and tags can also have multiple values separated by commas (posts in any of the categories or tags) or ‘+’ plus signs (posts which are in all of the categories or tags).

When combined with a thumbnail image, or placed into a table or list, you can now create pages like:

  • An author biography page, with automatic listing of the most recent posts by that author.
  • A category overview page — say, “Dessert Recipes” — that automatically shows the most recent desserts, and a thumbnail for each.
  • A page for a category — say, “France” — with a lead-in for the most recent articles with the “france” or “riviera” tags.
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Die Shapes and Radially Staggered Bonding

Posted on February 15, 2010 by bill

Over ten years ago I put aside my copy of the HP Journal, December 1996 edition for later reading.  I would like to relate some thoughts I have recently had on an article in it.

As pin counts of integrated circuits have continued to rise, the difficulties in arranging wire bonds — which connect the “pads” on the chip (die) to the landing zones on the “pins” that connect through the “device” (plastic or ceramic) to the outside world — have likewise continued to rise.  As the connections get closer, simply putting pads around the edge of the die makes them too close, and too small, to accurately bond with a flying piece of semi-molten gold wire.

The article shows micrographs of HP’s technique for radially staggered bonding. This does increase the available size and separation of the pads but it really only defers the problem.  Another problem with device yield is that the “street” which is traditionally cut by a saw requires a significant amount of area.

For a better overall solution, consider the bee’s honeycomb.

A honeycomb is a matrix of hexagons.  Not only is every cell nearly the same, but the amount of material used to construct the honeycomb is minimized.

If a silicon wafer were cut into hexagons, perhaps by a laser, that would reduce the amount of area lost. Further, because a hexagon more closely approximates a circle — which is the end convergence of the radially staggered bonding process.  (The clue is, “radial” — think … circle!)

This whole process could significantly increase both yield and pin count.

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Resolving Akismet on large existing WordPress sites

Posted on February 14, 2010 by bill

I recently enabled Akismet on a client’s WordPress site that had been running, and accumulating spam, for quite awhile.

Apparently there were so many spam messages (over 17,000!) that Akismet would hang with some kind of unreported out-of-memory condition.  There was nothing in the log files to indicate what might be causing the error.

The result was a blank page with an address like:

http://www.example.com/wp-admin/index.php?action=akismet_recheck_queue

I was able to get Akismet filtering running by manually starting mysql:

$ mysql databasename -u dbusername -p

and then deleting all the very old unapproved comments:

mysql> delete from wp_comments where comment_approved = 0
       AND comment_date < '2010-1-1';

You can see how many unapproved comments Akismet will try and filter:

mysql> select count(comment_ID) from wp_comments
       where comment_approved=0;

and after Akismet runs awhile, you can monitor its progress by counting the number of messages flagged as spam:

mysql> select count(comment_ID) from wp_comments
       where comment_approved='spam';

This completely resolved the problem.

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PostgreSQL connections

Posted on February 12, 2010 by bill

If you are using an application that needs PostgreSQL connections on your LAN, don’t forget to add, or replace, in file postgresql.conf –

listen_addresses ='*'

Otherwise, postgres will bind only to ‘localhost’ and won’t be accessible from your network. You will just get Connection Refused errors until you add this parameter to enable listening to TCP sockets. (That’s port 5432 if you look in /etc/services.)

NOTE: Webmin doesn’t give you a way to edit the parameters in postgresql.conf, you’ll have to do it manually.

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Controlling backscatter spam in Mailman

Posted on January 30, 2010 by bill

By default, Mailman — which is installed by default in Virtualmin as your mailing list manager, exhibits some nasty behavior, being open to sending “backscatter” spam.  This means that the Bad Guys send fraudulent messages “from” the email address they actually want to send spam to; Mailman rejects those messages, basically sending a bounce message to the victim.

The mechanism the spammers use is left over from the days before web interfaces.  Nowadays, your subscribers interact with Mailman almost exclusively via its HTTP interface.  Other than actual postings from subscribed members, and messages to the list owner, there is little or no reason to keep the vestigial email aliases.

To disable the vulnerable aliases:

With Virtualmin, go into the Webmin interface, under Servers; Postfix Mail Server; and click on the Aliases icon. You should see, for example, defined among the email addresses:

yourlist-example.com 	Program /usr/lib/mailman/mail/mailman post yourlist
yourlist-admin-example.com 	Program /usr/lib/mailman/mail/mailman admin yourlist
yourlist-bounces-example.com 	Program /usr/lib/mailman/mail/mailman bounces yourlist
yourlist-confirm-example.com 	Program /usr/lib/mailman/mail/mailman confirm yourlist
yourlist-join-example.com 	Program /usr/lib/mailman/mail/mailman join yourlist
yourlist-leave-example.com 	Program /usr/lib/mailman/mail/mailman leave yourlist
yourlist-owner-example.com 	Program /usr/lib/mailman/mail/mailman owner yourlist
yourlist-request-example.com 	Program /usr/lib/mailman/mail/mailman request yourlist
yourlist-subscribe-example.com 	Program /usr/lib/mailman/mail/mailman subscribe yourlist
yourlist-unsubscribe-example.com	Program /usr/lib/mailman/mail/mailman unsubscribe yourlist

for “yourlist@example.com” … I recommend you disable these aliases shown in bold above:

-admin-, -confirm-, -join-, -leave-, -request-, -subscribe-, -unsubscribe-.

You will want to do this for each mailing list on your system.

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Setting up Zonet 2102 print server on Ubuntu Linux

Posted on January 29, 2010 by bill

For setup of the Zonet ZPS2102:

The default IP is 192.168.0.10 … in the Add Printer dialogs, choose Network Printer, then enter the IP address, the queue (default is: LP1) and choose the model.

The Device URI, when you are done, looks like:

lpd://192.168.0.10/LP1
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Anti-virus and anti-spyware recommendations

Posted on January 25, 2010 by bill

Here are our currently recommended software packages:

  • ComboFix
  • Super Anti Spyware
  • Malwarebytes
  • Avast
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Subversion 1.6 on Debian (Lenny)

Posted on January 21, 2010 by bill

See the instructions at http://backports.org/dokuwiki/doku.php?id=instructions

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Grace Hopper Quote

Posted on November 17, 2009 by bill

A human must turn information into intelligence or knowledge. We’ve tended to forget that no computer will ever ask a new question.
— Rear Admiral Grace Murray Hopper

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What’s a blog?

Posted on November 14, 2009 by bill

Blogging is where you write an article or two every day, and it really does have to be at least one a day, about an issue.

Usually blogs attempt to develop a community of readers, all of whom get to discuss each post on the blog site.

Blogs are mostly used to discuss political and social issues. The comments are wide-ranging and often become shouting matches.

If you want to push an issue, to get people excited about something, a blog is great.

If you’re trying to sell something, you’ll either wind up with silence (which is bad) or people shouting and complaining (worse).

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