May 1, 2000

By Karen Kenworthy

IN THIS ISSUE

May Day! May Day!

No, I'm not sounding the International Distress Call. Today's the first day of May, and I'm excited! Mayday's arrival is a sure sign of Spring for those of us who live on the "top" half of the globe. And Spring's my favorite season -- at least until the next season comes around. I love to go barefoot, and dig my toes into the cool grass, or moist garden soil. Straw hats, cotton dresses, sandals for the more formal occasions. What could be better?

DiscomBUGulator

Hereabouts, May flowers are already in full bloom. But with flowers come bugs. And one of those critters must have found its way into the URL Discombobulator we talked about last week. Hellmut Golde was the first to write about the program's problem with four-part domain names.

Normally, domain names consist of three parts. The left-most part identifies a particular computer, while the middle part identifies a local network of computers. The right-most part, usually "com" or "net," identifies the type of organization that owns the domain name. Each part is separated from the others by a dot ("."). For example, www.microsoft.com refers to a computer named "www", on a network named "microsoft", owned by a commercial enterprise.

But not all domain names have three parts. Some, such as winmag.com, have just two. In that case a default computer (in this case "www") is accessed on the microsoft network. Other domain names have four, or more, parts. Usually, this indicates the computer resides within a hierarchy of networks, with larger networks consisting of two or more smaller networks. The URL www.net1.microsoft.com, for example, might refer to a machine named "www", on a small network named "net1", which might be part of a larger network named "microsoft."

Unfortunately, when the URL Discombobulator saw three dots (".") in a four-part domain name, it thought it was dealing with an IP address in the familiar dotted quad format. But IP addresses, such as 199.233.144.10, only contain digits and dots. No letters or punctuation marks are allowed. Trying to digest a domain name, as if it were an IP address, gave the Discombobulator indigestion. The telltale symptom was a cryptic error message reading "Error 13: Type Mismatch."

As a result, I spent part of last week teaching the URL Discombobulator Version 1.2 to be more careful.

ASCII II

While I was working with the Discombobulator, Michael Girard sent me an interesting suggestion: "I'm a beginner programmer with VB6 and I was wondering if in your next issue you could mention how to get a good ASCII chart. Unfortunately I don't have it memorized yet."

Michael's idea was so good, I stole it. Well, borrowed it, if I may. The new Discombobulator now has three tabs on its main window. The new tab, "ASCII", displays an ASCII Code table. And now just any ASCII Code table, either. In the first column, this table lists all the digits, letters, and punctuation marks defined by the ASCII standard. In the next column, you'll find the decimal number assigned to each character. Column three contains the same number, in hexadecimal notation, while the last two columns show that number in "Octal" and Binary form.

In recent weeks we've talked a bit about decimal, hexadecimal, and binary numbers. Decimal numbers are composed of 10 distinct digits, 0 through 9. Hexadecimal numbers are formed using 16 different digits, 0 through 9 plus A, B, C, D, E and F. And as we all know, binary numbers consists of just the digits 0 and 1.

As their name suggests, Octal numbers rely on just eight digits, 0 through 7. They're not often seen these days, but they're still used by programmers in some situations. You might think of them as hexadecimal's little brother, representing numbers using only half as many different digits as the more common hexadecimal notation.

More URLs

Well, you know what happened next. The bits of the new Discombobulator weren't even dry when a message arrived from Mark Rapp: "Hi Karen -- I've a request of you ... When URL Discombobulator v1.1 returns the URLs after inputting an address, could you please permit multiple selection of the results (e.g. to select all, use Ctrl-A, to select a range select 1st end of range than hold the Shift key and click on the other end of the range, etc... you get the picture). Makes it easy to copy."

Mark, some ideas just make sense. Windows' list boxes, like the one the Discombobulator uses to display the "shrouded" URLs it generates, come in three "MultiSelect" flavors: none, simple, and extended. If the box's MultiSelect property is set to "none", only one of the box's entries can be selected at a time. The original Discombobulator's URL box worked that way.

But if the box's MultiSelect property is set to "simple", then more than one of the box's entries can be selected at the same time. It's done by clicking on one entry with the left button of your mouse, then holding down the key on your keyboard and clicking on another list box entry with your mouse. Automatically, the two list box entries are selected, as are all entries in between. This is sometimes called a "contiguous block selection" (though never in polite society).

The new version of the Discombobulator uses the third style of list box, one whose MultiSelect property is set to "extended." This list box supports the "contiguous block selection" feature. But it also allows you to add additional entries to your selection by holding down a <Ctrl> key while clicking an entry with your mouse. Do that, and the single entry under your mouse pointer is added to the group of entries you've selected. The result can be (please pardon my language) a "non-contiguous group selection."

Now, when you click the Discombobulator's Copy button, all selected URLs are copied to the Windows clipboard. This might be any, or all, of the available entries. When copied to the clipboard, each entry is treated as a separate line of text.

If you'd like to get the new, freshly debugged, list box enhanced, URL Discombobulator, with free ASCII Code table, simply drop by my Web site at https://www.karenware.com/powertools/ptlookup. While there, help yourself to the program's updated Visual Basic source code. As always, they're both free.

And when you find the time, go outside and enjoy this special time of year. Take off your shoes, walk on the grass, smell a flower, even climb a tree. And if you see me passing by, be sure to wave and say "Hi!" But don't let go of that branch!