Tod means Fox

According to this article, “Microsoft Releases Virtual Vista Versions” by Keith Ward, Visual FoxPro 9.0 is one of only 3 development languages supported on Window’s Vista. Is this true? Where’s the fine print?”

Developers may be excited by the Vista with VS 2005 option. Currently, Microsoft supports Vista for three Microsoft development products: Visual Basic 6.0, Visual FoxPro 9.0 and VS 2005, but only with the Service Pack 1 Update for Windows Vista. Versions of VS 2003 and earlier aren’t supported by Microsoft. Earlier development products may work with Vista, Microsoft said, but it won’t support them.

I just thought I’d pass this along!

What I find interesting (and maybe I’m wrong?) but VB6 is no longer supported by MS. That leaves Visual FoxPro and VS 2005 as the only two development platforms available and supported on Vista.

This just in:

Fans trumpeting the cause of CBS’ canceled drama “Jericho” have caught the network’s ear. CBS, deluged with calls, messages and shipments of nuts signifying viewer displeasure, is reconsidering its decision, a source close to the production said Tuesday.

The source spoke on condition of anonymity because he was not authorized to comment publicly. A decision on whether to bring the show back, probably for a midseason run, is imminent, the source said.

Yahoo! Looks like all those nuts are making a grand impact!

In my series, “Business Intelligence Through Web Analysis“, I talk about using web stats to build a web analytics solution in FoxPro. I have created a webstats table, and have populated it with some data from my access logs. I have a requirement to be able to sort my webstats table by IP address (among other things).

The format of an IP address doesn’t lend itself to proper indexing (it is a 32-bit numeric address written as four numbers (octets) separated by periods). To accommodate my requirement, my first thought was to break the IP address into 4 separate numeric fields when importing. This would be good normalization. After all, the rule is that atomic data is better than concatenated data. But rules are meant to be broken. And, more importantly, does it make sense to atomize an IP address? An IP address is not really 4 separate numbers, the entire address is meaningful, even though each piece holds some significance.

So, I decided to keep the IP address intact.

Still needing a good way to sort and group, I thought about converting the IP address to its binary representation. MySQL has a function, INET_ATON (Adress TO Number), that does exactly that. FoxPro’s CREATEBINARY function seems to do the trick at first. I can pass in the complete IP address like so:

? CREATEBINARY("128.0.0.0")
? CREATEBINARY("168.212.226.204")

But if you see these outputs, you’ll realize that they’re not great for indexing (which is the only reason I want to convert them). CREATEBINARY creates strings of varying length, which is not what I want for indexing.

Back to the drawing board. I could represent each octet as 0 and 1 like this:

lnOct = 122
lcBin = ''
DO WHILE lnOct > 0
    lcBin = STR(lnOct%2, 1) + lcBin
    lnOct = INT(lnOct/2)
ENDDO
? PADL(lcBin,8,'0')

But this seems terribly inefficient (I admit, no benchmarking was done, but this code is overkill!).

With all this in mind, I think I have a viable solution. It doesn’t require a custom function, nor does it require storing data in separate fields. I know I can easily extract each octet of the IP address by using GETWORDNUM. And, knowing a little something about IP addresses, each octet has 2^8 (or 256, values 0 to 255) possible combinations. Therefore, an IP Address can be represented in a numeric form like so:

? VAL(GETWORDNUM(ip_address,1,'.')) * 256^3 + ;
  VAL(GETWORDNUM(ip_address,2,'.')) * 256^2 + ;
  VAL(GETWORDNUM(ip_address,3,'.')) * 256   + ;
  VAL(GETWORDNUM(ip_address,4,'.'))

So my index for webstats.dbf would be:

SELECT webstats
INDEX ON BINTOC( ;
    VAL(GETWORDNUM(ip_address,1,'.')) * 256^3 + ;
    VAL(GETWORDNUM(ip_address,2,'.')) * 256^2 + ;
    VAL(GETWORDNUM(ip_address,3,'.')) * 256 + ;
    VAL(GETWORDNUM(ip_address,4,'.'));  ,8) TAG IP

Your comments and feedback are welcome. Is there a better solution?

Advisor just put out a great new article titled “Let Visual FoxPro Check File Permissions“. Here is a taste:

Regardless of what one thinks of Windows Vista, without doubt it made developers think about permissions security. Where in the past a user could consider himself lucky when an application at least displayed an Access Denied error message instead of silently failing, we now see developers investigating what permissions and privileges their application really needs. However, Windows doesn’t exactly make this an easy task.

This article was written by Christof Wollenhaup. More from Chris.