The Old New Thing

November 2004 - Page 2 of 3 - The Old New Thing

Poking at diploma mills: Kennedy-Western University

November 17, 2004 Nov 17, 2004 11/17/04
Raymond Chen
I enjoy poking around diploma mills. Especially the ones that spam my inbox. Like Kennedy-Western University, which describes itself like so: Since 1984 Kennedy-Western University (KWU) has provided distance and online degree programs to over 30,000 students. KWU is one of the largest non-accredited online universities in the United States...

How do I break an integer into its component bytes?

November 17, 2004 Nov 17, 2004 11/17/04
Raymond Chen
Warning: .NET content ahead. For some reason, this gets asked a lot. To break an integer into its component bytes, you can use the BitConverter.GetBytes method: int i = 123456; byte[] bytes = BitConverter.GetBytes(i); After this code fragment, the byte array contains { 0x40, 0xE2, 0x01, 0x00 }. Update 11am: The endian-ness ...

Exploiting the inattentive

November 16, 2004 Nov 16, 2004 11/16/04
Raymond Chen
The makers of a certain major brand of detergent which I will not name (but which for the purposes of this discussion will be called "Snide") appears to take every step to exploit inattentive customers. A box of Snide detergent powder comes with instructions indicating that for a normal-sized load, you should use 3/8 cup of detergent; for a ...

What is this Xerox directory doing in Program Files?

November 16, 2004 Nov 16, 2004 11/16/04
Raymond Chen
If you go snooping around, you may find an empty directory. What's that for? This directory is being watched by Windows File Protection, because it needs to protect the file should it ever show up. (Why does the directory have to exist in order for Windows File Protection to be able to watch it? I'm told it's a limitation of the Windows ...

Asking questions where the answer is unreliable anyway

November 15, 2004 Nov 15, 2004 11/15/04
Raymond Chen
Here are some questions and then explanations why you can't do anything meaningful with the answer anyway even if you could get an answer in the first place. "How can I find out how many outstanding references there are to a shared memory object?" Even if there were a way to find out, the answer you get would be instantly wrong anyway ...

Will dragging a file result in a move or a copy?

November 12, 2004 Nov 12, 2004 11/12/04
Raymond Chen
Some people are confused by the seemingly random behavior when you drag a file. Do you get a move or a copy? And you're right to be confused because it's not obvious until you learn the secret. Mind you, this secret hasn't changed since 1989, but an old secret is still a secret just the same. (Worse: An old secret is a compatibility ...

Advantages of knowing your x86 machine code

November 11, 2004 Nov 11, 2004 11/11/04
Raymond Chen
Next time you find yourself debugging in assembly language (which for some of us is the only way we debug), here are some machine code tricks you may wish to try out: 90 This is the single-byte NOP opcode. If you want to patch out code and don't want to think about it, just whack some 90's over it. To undo it, you have to patch ...

Why does Windows not recognize my USB device as the same device if I plug it into a different port?

November 10, 2004 Nov 10, 2004 11/10/04
Raymond Chen
You may have noticed that if you take a USB device and plug it into your computer, Windows recognizes it and configures it. Then if you unplug it and replug it into a different USB port, Windows gets a bout of amnesia and thinks that it's a completely different device instead of using the settings that applied when you plugged it in last time...

A history of GlobalLock, part 4: A peek at the implementation

November 9, 2004 Nov 9, 2004 11/9/04
Raymond Chen
On one of our internal discussion mailing lists, someone posted the following question: We have some code that was using DragQueryFile to extract file paths. The prototype for DragQueryFile appears as follows: UINT DragQueryFile( HDROP hDrop, UINT iFile, LPTSTR lpszFile, UINT cch ); In the code we have, instead of ...

A history of GlobalLock, part 3: Transitioning to Win32

November 8, 2004 Nov 8, 2004 11/8/04
Raymond Chen
Now that you know how the 16-bit memory manager handled the global heap, it's time to see how this got transitioned to the new 32-bit world. The function continued to emulate all its previous moveability rules, but the return value of was no longer a selector since Win32 used the processor in "flat mode". This means that the old trick ...