• Happy Pi Day

    In honor of Pi Day, I thought I would write a little Ruby script to generate pi to a few decimal places.

    A quick trip to the Wikipedia page for pi turned up many formulas for computing pi. I took one of the easy ones and set about writing some code.

    Most of the formulas involve the factorial function. Unfortunately, Ruby doesn’t have a built in method for computing the factorial. After a little Googling, I found a nice, functional example at the Rosetta Code wiki.

    Putting that all together, I ended up with this:

    def fact(n)
      (1..n).reduce(1, :*)
    end
    
    sum = 0.0
    
    (0..8).each do |n|
      a = fact(2 * n) ** 3.0
      b = 42.0 * n + 5.0
      c = fact(n) ** 6.0
      d = 16.0 ** (3.0 * n + 1.0)
    
      sum += (a * b) / (c * d)
    
      puts 1.0 / sum
    end
    

    Note that I’m only iterating 8 times. On my PC, that gives pi out to 15 decimal places which is all of the precision available in a floating point number.

  • Exploring ODBC with Ruby DBI

    I recently found myself in an interesting situation. I needed to extract data from a database. Unfortunately, all I had to work with was an ODBC name.

    If this were a MySQL database, I would have used the command-line interface to check out the structure and see what was available.

    In this case, I didn’t have a command-line interface. What I did have was Ruby and irb. Here’s how I got the job done.

    Required Gems

    Three gems are required to make this work. First, we need dbi and a driver (or dbd). The dbd-odbc driver also requires the ruby-odbc gem.

    dbi
    dbd-odbc
    ruby-odbc
    

    In order to install ruby-odbc on Windows, you will need to compile it from source. I used the excellent DevKit provided with the RubyInstaller and had no problems.

    Connect

    Let’s assume that the ODBC Data Source Name is “TestData”. First, we require the DBI library, then connect to the data source.

    require 'DBI'
    
    dbh = DBI.connect("DBI:ODBC:TestData")
    

    You can also pass a username and password after the connection string if required.

    List and Describe Tables

    Now that we have a connection, let’s see what tables are available.

    dbh.tables
    

    My test database only has one table. It’s called “Table1”. Let’s list the columns in this table.

    dbh.columns "Table1"
    

    This will tell us the type of data stored in each field in addition to the name.

    Query For Data

    In order to see the actual data, we can prepare and execute an SQL query. In this case, the separate prepare and execute is not really necessary, but it’s a good habit to get into.

    sth = dbh.prepare("SELECT * FROM Table1")
    sth.execute
    
    row = sth.fetch
    

    The fetch method will return a row of data at a time until there is not more data. At that point it returns nil. Calling fetch again after it returns nil will result in an exception.

    A Complete Example

    Here’s a simple example of connecting to the ODBC database and displaying all of the data in a tab separated format.

    require 'DBI'
    
    dbh = DBI.connect("DBI:ODBC:TestData")
    
    sth = dbh.prepare("SELECT * FROM Table1")
    sth.execute
    
    puts sth.column_names.join("\t")
    
    while row = sth.fetch
      puts row.join("\t")
    end
    
    sth.finish
    dbh.disconnect
    

    You could also require the CSV class and use it to generate comma-separated output.

  • To Hex and Back (With Ruby)

    I am a big fan of plain text. It is easy to view and easy to edit. Unfortunately, it is sometimes necessary to work with binary files and data.

    Ruby’s inspect method does a decent job of showing the contents of a binary string, but sometimes I need something a little more powerful.

    Back in the day I would use a hex editor to open binary files and decipher their contents. I don’t have a need for a hex editor anymore, but I would like to occasionally view binary data in the same format.

    After some intense Googling and Ruby doc reading, I came up with a few methods to convert a binary string to hex, and convert a string of hex back to the original binary.

    Bin to Hex

    To convert a string to it hex representation, first take each byte, convert it to hex, then join all of the hex digits back together.

    def bin_to_hex(s)
      s.each_byte.map { |b| b.to_s(16) }.join
    end
    

    If you like spaces between the hex digits, change join to join(‘ ‘)

    Hex to Bin

    Converting the string of hex digits back to binary is just as easy. Take the hex digits two at a time (since each byte can range from 00 to FF), convert the digits to a character, and join them back together.

    def hex_to_bin(s)
      s.scan(/../).map { |x| x.hex.chr }.join
    end
    

    If you find yourself using these frequently in a project, you could add the methods to the String class.

    TIMTOWTDI

    Of course, there is more than one way to do this. Ruby also provides the handy pack and unpack methods for Arrays and Strings respectively. These are a little more cryptic since you need to know the meaning of the format string to understand what’s going on.

    def bin_to_hex(s)
      s.unpack('H*').first
    end
    
    def hex_to_bin(s)
      s.scan(/../).map { |x| x.hex }.pack('c*')
    end
    

    Check the Ruby documentation for Array and String for a complete explanation of pack and unpack.

    Examples

    Here’s the output of a quick IRB session to demonstrate how this works.

    irb(main):001:0> s = "Hello, World!"
    => "Hello, World!"
    
    irb(main):002:0> s = s.each_byte.map { |b| b.to\_s(16) }.join
    => "48656c6c6f2c20576f726c6421"
    
    irb(main):003:0> s = s.scan(/../).map { |x| x.hex.chr }.join
    => "Hello, World!"
    

    These methods are no replacement for a hex editor, but if you need to check an encryption key or some other short string of binary, they can be just the thing.

  • 10 Years

    I remember September 9, 1999 like it was yesterday…

    Paige and I were living in a tiny upstairs apartment. Thanks to a friend of a friend, we were some of the first people in town to have a cable modem.

    Back then it was uncapped and since we were officially helping to “test” it, I think it was free for the first few months. Going from around 50k dial-up to at least 5,000k cable made the internet a lot more enjoyable.

    Also around this time I discovered a new program called Napster. It was a friendly place where people got together and shared music.  While you were downloading songs from other users you could chat with them about their collections.

    The generosity of others, combined with the cable modem, meant I was able to download music faster than we could listen to it. It was fun to have friends over on the weekend and let them pick what they wanted to hear from my endless jukebox.

    This was also around the time of our complaint to Domino’s Pizza.  Our pizza arrived cold, and Paige called to tell them about it.  The person on the phone replied “No problem Ms. Lewis.  We’ll get another pizza out to you right away.  You’re one of our best customers.  You’ve ordered over 100 pizzas this year.“  Apparently we ate a lot of pizza in those days.

    The big news story at the time was Y2K.  Many people believed that at the stroke of midnight on December 31, 1999 every computer in the world would stop working.  This would cause a world-wide black out, stock markets would crash, dogs and cats would live together, etc.

    I set the clock on my computer ahead to December 31, 1999 at 11:59 PM and watched it roll over to January 1, 2000.  Nothing bad happened so I wasn’t too worried.

    In an effort to make Y2K seem a little scarier, some news outlets also reported on the 9-9-99 bug.  Supposedly, four nines was the code that told some mainframes to end the currently running program.  The theory was that when the mainframes encountered this date, they would stop working.

    This sounded as ridiculous to me then as it does now. So, on September 9, 1999 I wrote my first ever blog post about the 9999 bug.  (That’s right kids, I was blogging when blogging wasn’t cool.)

    I had a few web pages before that date, but this was the first thing I ever wrote in the “blog” style.  It was a title with a few paragraphs of text, posted on a certain date. I didn’t call it a blog, of course. I had seen a few people set up their web sites like this before and I wanted to try it out myself.

    Things have changed a lot since those days.  Back then I updated the site by editing the HTML in notepad and using WS_FTP to upload the pages to a web server.  I’ve moved on through several different programs to write blog posts, but I made sure to preserve that first post through all of the moves.

  • Die Spammers

    Do you have your own blog?  Is it full of spam?  Are you sure?

    A while back a friend of mine asked me a question about her blog.  Everything looked normal in every newsreader except for Google Reader.  In Google Reader every post appeared to be nothing but pharmacy spam.

    I looked for the spam in view source, I downloaded the feed and checked it, I even crawled through the PHP code looking for a clue.  Everything looked perfectly normal.  It wasn’t until I started digging through the database, that I discovered what was happening.

    Somehow, the spammers replaced two plugins on her site with their own malicious plugins.  These new plugins changed the contents of each post based on the referrer.  That’s why spam only showed up when viewed by Google.

    The clue was in the “wp_options” table in a field called “active_plugins”.  I noticed a couple of plugins that started with a dot.  For example, instead of “akismet/akismet.php”, the name was more like “akismet/.akismet.php”.

    In Unix, file names that begin with a dot are hidden by default.  The initial dot is so subtle that most people won’t even notice it in the database.  Especially since there’s lots of other information in that field.

    Discovery

    Here’s a simple way to check your site for this kind of spam.  You can restrict a Google search to a single site by adding “site:domain” to your query.  For example, to search for the word Vaigra on my site try something like this:

    viagra site:anthonylewis.com
    

    This should only show one result for my site - this page.   Put your domain name in place of “anthonylewis.com” to see the results for your site.  If you get lots of results, then you have a problem.

    Removal

    The first thing I did to remove the spam was change all of her passwords - WordPress, Database, and FTP.  We used much more secure passwords.  I have another post in the works that addresses secure passwords.

    Next, I made sure she was running the latest version of WordPress.  Updating WordPress is getting easier all the time.  It’s always been a simple 2-3 step process, but now it’s almost automatic.

    Finally, I removed the plugin files with the initial dots and cleared the “option_value” from the database for “active_plugins”.  This disables all of the plugins.  Don’t forget to enable the ones you really need.

    Aftermath

    Unfortunately, the spam on her site still shows up in Google’s cache.  It’s been over a week now.  I’m not sure how long Google keeps pages in their cache, but this should go away soon.

    One option I would recommend if you’re having a problem with stale data in Google’s cache is the Google XML Sitemaps plugin.  This plugin maintains an XML file that lets Google know where to find things on your site and when they were last updated.

    Help

    Let me know if you’re having this problem.  I have a lot of experience working with WordPress and I would love to help you out.  My contact information is at the bottom of this page.

    I provide advice and guidance for free.  If you’d rather I log on to your site and completely remove this mess, I’ll do that for a small fee.

  • Why Facebook Will Fail

    Everyday I log in to Facebook to see what my friends are up to.  It’s a great way to keep up with my old friends who are now 300 miles away.  Even with all of it’s current popularity, I feel like it will fade away in time.  Here are my reasons.

    The Platform Was A Mistake

    Thanks to the Facebook Platform, there’s always a new silly quiz to take or some other application wanting my attention.  I mostly ignore those things, but sometimes I give in.

    This is where the problems start.  It’s not enough to just take the quiz, the quiz also wants you to invite all of your friends to take it, too.  Also, by taking the quiz, you have to agree to give the program access to all of your information on Facebook.

    This has always struck me as a little odd.  I usually spend as much brainpower trying to make sure that this program doesn’t e-mail everyone on my friends list as I do actually taking the quiz.

    Facebook Quiz

    I believe a social network should be centered on the people involved.  They’re the reason the site exists.  The applications are just a distraction to get people to spend more time looking at the ads.

    It’s a Walled Garden

    Facebook released their API partly in response to my second criticism.  It’s closed.  There’s no way to share things on Facebook with other people, unless they’re also members.

    What if I want to share my pictures and status updates with everyone?  This isn’t possible with Facebook, yet sites like Flickr and Twitter make it easy.  Also, what if I want to export my data from Facebook?

    The Platform could easily be used to create applications to make sharing easier, but it’s against the terms of service.  Facebook recently shut down an application that made your data available as an RSS feed citing privacy concerns.

    This is kind of a double-edged sword.  I think one of the initial reasons for Facebook’s rise to popularity was the fact that it was initially only available to college students.  It was like a private club.  Obviously, that made outsiders want in even more.

    Now that the site is available to all, there should be a way to make the data more readily available.

    It’s Nothing New

    Like I mentioned earlier, there are many other ways to share your information online.  Facebook is nice if you didn’t already have a blog or some other means of sharing your thoughts and pictures online.

    Facebook does make it easier to keep up with friends, but it’s not rocket science.  A group of tech-savvy friends could just as easily set up a blog for each person, then subscribe to all of their RSS feeds.

    For me, it seems like just another inbox sometimes.  Why should someone send me a message through Facebook, when they could just e-mail me?

    I’ve also starting using the Twitter application so that my Twitter updates also update my status on Facebook.  If there was an application to make my friends status show up as a feed, I would probably never visit Facebook.

    Thanks to the fact that the site is fueled by advertising, that’s never going to happen.

  • Blog Posts I'm Tired of Reading

    I read quite a few different blogs.  I feel like I should since I sometimes write one.  I read mostly about programming and other technical things.  I probably spend 10-15 minutes per day skimming the headlines in Google Reader, looking for interesting articles.

    It’s nice to have a few things to read while I’m waiting for a script to run or eating lunch.  Unfortunately, there are certain types of posts that seem to reappear regularly.  These are a few of the posts that I’m tired of reading:

    How To Make Money Blogging

    I know that some people make their living as a blogger, and I think that’s great, but I’m tired of reading about it.  What I really can’t stand are people who make money by writing a blog about how to make money blogging.

    I’ve fallen into this trap myself in the past.  I created a few different blogs with Google and Amazon ads.  I even made a little money doing this, but it’s not something I can maintain for any length of time.

    Blogs with lots of ads (especially ads that pop up on words inside the posts) make me a little uncomfortable.  Like I said, I still have a few blogs with ads on them, but I don’t really feel good about it.

    If I never see another post about link baiting, SEO, or how to get on the front page of Digg again, it’ll be too soon.

    Arguments About Nothing

    For some people, everything is a religion.  There is no gray area, everything is black and white.  You’re either with us or you’re against us.  Windows vs. Mac, Emacs vs. Vi, Windows vs. Linux, Ruby vs. Python, the list goes on forever.

    Use the right tool for the job and get on with your life.  Just because I use a Mac at home doesn’t mean I’m an idiot.  I use a Windows PC at work, and that doesn’t mean I don’t like Macs.

    The worst are posts written by people who don’t really even know what they’re talking about.  For example:

    “You should use a Mac since Windows computers always get viruses.”  I’ve never had a virus on any of the Windows PCs I’ve used.  Am I just lucky?

    “Macs are overpriced, you can get a PC with the same hardware for a lot less.”  I look at a lot more than hardware specs when I buy a computer.  What about the operating system, the applications, the community, the build quality, the design?

    I will never understand why some people spend every day of their life trying to convince other anonymous internet users that their way is the only way.  What a waste of time and effort.

    Personal Attacks

    To me, this is about the lowest thing you could possibly write about online.  Yet I still see these kinds of posts on blogs.

    I can’t even imagine a situation that would cause me to try to belittle someone else online.  What can a post like this possibly accomplish? If you don’t agree with someone, why not just ignore them?

    Maybe it has something to do with television.  Some people aren’t happy unless there’s drama in their life.  I guess it’s nice when people comment on the post and agree with your assessment of the other person.

    Just like the endless debates I mentioned earlier, I’ve never seen anything positive come from a personal attack of someone online.  I don’t ever remember a time when a victim of one of these posts said “You know what, you’re right.  I’ll change my ways.”

    That’s Enough For Now

    I think I’ll stop here.  I’m not really sure what the point of this post was.  I don’t imagine it will change what other people write about, but it can’t hurt to try.

    Maybe later I’ll talk about the kinds of posts that I enjoy reading.  In the mean time, what are some posts that you’re tired of reading?

  • Unblocking Attachments in Outlook

    Microsoft Outlook is the mail client we all love to hate.  My personal favorite feature is the way it handles attachments.  If you’ve used Outlook very much, I’m sure you’ve seen this message:

    blocked-att

    Here Microsoft is protecting you from itself by blocking an Access database attachment.  The attachment is still there, you just can’t get to it.  Very frustrating.

    The recommended solution is to use a program like WinZip to compress the file before you e-mail it.  You can also just change the extension since Outlook doesn’t actually check to see what kind of file it attached.  Both of these can be a hassle for the sender, so I started looking or a better solution.

    Google To The Rescue

    Spend a little time researching this problem and you’ll see that there is a lot of information online about how to get around this message.  I was able to solve the problem, but it involved using information from several different sites.  This is my attempt at putting all of the information together into a series of easy steps.

    Check The Mode

    First, you need to find out what Security Mode access is using.  To do that, click Help, About Microsoft Office Outlook on the menu.   You should see a screen like this:

    sec-mode-def

    This means I’m currently using the “Default” Security Mode.  The other options are “User Controlled” and “Administrator Controlled”.  If yours says “Default” or “User Controlled” you can follow my steps and unblock attachments.

    If you’re in “Administrator Controlled” security mode, then you’ll need to talk to your e-mail administrator.  If anyone really wants to know, I can also tell you how to get around “Administrator Controlled” mode, but that’s a post for another day.

    Now click OK to close the “About” window and exit from Outlook.

    Edit The Registry

    The next few steps involve editing the registry.  Be very careful when you do these steps.  It’s pretty easy to break Windows by changing the wrong settings in the registry.  If you break it, you get to keep both pieces.  I won’t be able to help you unless you’re willing to bring your computer to my house.

    Click Start, then Run.  Type regedit and click OK

    Drill down in the registry to this key:

    HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Security
    

    Once you get there, right-click on Security and click New, String Value.

    Type in Level1Remove for the name, then double-click Level1Remove to edit the value.  This value is a list of extensions you want to unblock separated by semicolons.  For this example, you can type .mdb  It should look something like this:

    reg-key

    Click OK to save the value, then close the Registry Editor and reopen Outlook.

    Success

    If you added the registry key in the right place, Outlook should now be in the “User Controlled” security mode.  Also, you should see something like this when you open an e-mail with an Access database attached:

    unblocked-att

    Now you can add any other file extensions that you don’t want to block to the same key in the registry.  Just be sure to separate each one with a semicolon and include the dot before the extension.

    Leave a comment below if you have any trouble and I’ll try to help you out.

  • How I Write

    That post from last week is one of the most boring things I’ve ever written.  I used every trick I knew to make it interesting, but I couldn’t make it work.  After messing with it for about half an hour, I gave up and clicked Publish.

    There was a time when I would have deleted it without a second thought, but this was a story I wanted to share and I thought it might be an interesting experiment.  One positive side effect of this was I started seriously looking at how I write.

    Voice

    I try to write how I speak.  Denise gave me a great compliment the other day when she left the comment “It’s so good to hear your voice again.”  That’s exactly what I’m trying to do.

    As I write, I try to hear the words in my head.  If a sentence or phrase doesn’t sound natural, I go back and rewrite it immediately.  In some cases I rewrite parts of a sentence several times until I end up with something completely different.

    I also sometimes write posts entirely in my head.  If there’s a topic that I just have to write about, I will have most of it written before I ever touch the keyboard.  An example of this would be my Continuous Improvement post from while back.

    Writing

    I am a fast typist.  At one time I could probably think as fast as I type, but I don’t think that’s true anymore.  I’m sure it’s just old age catching up with me.

    I guess that’s why I tend to type a lot more words than are actually needed to express what I’m trying to say.  My first drafts are filled with adjectives and adverbs that never make it to the finished product.

    This might also go back to the days in high school when papers were graded on content as well as length.  It’s almost like we were being taught that it takes a lot of words to make a point.

    Editing

    I make quite a few changes while I write, but once I have a complete first draft I really start editing.  I spend at least as much time deleting, cutting, and pasting as I did writing.  Most of those extra words I mentioned earlier disappear at this point.

    I also look for words that don’t add anything to a sentence like “really” and “just”.  For example, a sentence like “I really want to just write.” becomes “I want to write.”

    While I’m editing I also like to preview how the post will look on the page.  That way I can quickly spot paragraphs that seem too long.  At this point sentences and paragraphs get moved around.  Sometimes entire paragraphs disappear.

    Done

    Once a post sounds like me, doesn’t contain too many extra words, and flows well on the page I click publish and see what everyone else thinks about it.

  • So, What Do You Do?

    One of my favorite scenes from Office Space is when Peter is explaining to the consultants what he does in a typical day.  My day isn’t quite as funny, but I thought some people might find it interesting.  So, here is a day in the life of a security analyst.

    I arrived at work around 7:00 AM this morning and looked over the e-mail in our project mailbox to see if there was anything urgent.  There was not much going on, so I finished my coffee while looking over headlines in Google Reader.  Moments of peace are pretty rare.

    A little before 8:00 AM, one of the developers stopped by to talk about a scheduled task that was set to run on one of the servers.  This task failed after the last upgrade and he was confirming that it was fixed.  We also spent some time looking at the differences between the test server and production server.

    Around 9:30 AM, I had a meeting with two auditors.  They are working on an audit of user accounts on a few servers.  We went over a few spreadsheets that I had provided them earlier and discussed all of the accounts.   Thankfully, this only took about 45 minutes.

    Next, I helped troubleshoot a problem on one of the servers that was running slow.  One of the volumes was filling up so three hard drives were added to the RAID array last weekend.  Unfortunately, someone added Ultra3 SCSI drives instead of Ultra-320 SCSI drives.  Ultra3 drives run half as fast as Ultra-320.

    I also completed an access request and replied to a question about remote access before lunch.  I usually go for a walk during my lunch hour, at least around the building.   Today I just walked down to the cafeteria and grabbed a Snapple to go with my microwave meal before getting back to work.

    Last week we received the results from a penetration test that was performed on our network.  I’ve been working in my spare time to come up with a solution to an SQL Injection vulnerability that was discovered in one of our old web applications.

    This isn’t really part of my job, but I volunteered to take a look at it since the application isn’t being actively maintained right now.  I finished up my solution, tested it, and e-mailed a developer to see about getting it implemented around 12:30 PM.

    From 1:30 PM until 2:30 PM I attended a staff meeting downstairs.  There are 10 people in my group and we get together once a week to talk about what we’re working on.  The meetings are always informal.  Today’s meeting was a little dry since we talked about the budget, but it wasn’t bad.

    As the day winds down, I look over my Inbox to make sure I’m not falling behind on any projects.  There are only 4 messages in my box right now, so this doesn’t take long.  Two of these are about training that I need to look at and the other two are concerning ongoing projects.

    This was actually a really slow day for e-mail.  I only received 10 and sent 5.  Yesterday I sent 50 messages.  We all take turns covering our project mailbox one day a week.  Yesterday was my day.

    Now it’s 4:00 PM, which means quitting time for me…

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