The Old New Thing

November 2004 - The Old New Thing

What’s the difference between GetKeyState and GetAsyncKeyState?

November 30, 2004 Nov 30, 2004 11/30/04
Raymond Chen
I've seen some confusion over the difference between the function and the function. returns the virtual key state. In other words, reports the state of the keyboard based on the messages you have retrieved from your input queue. This is not the same as the physical keyboard state: When should you use and when should you use...

Why doesn’t the RunAs program accept a password on the command line?

November 29, 2004 Nov 29, 2004 11/29/04
Raymond Chen
The RunAs program demands that you type the password manually. Why doesn't it accept a password on the command line? This was a conscious decision. If it were possible to pass the password on the command line, people would start embedding passwords into batch files and logon scripts, which is laughably insecure. In other words, the ...

Simple things you can do with the ShellExecuteEx function

November 26, 2004 Nov 26, 2004 11/26/04
Raymond Chen
Here's a tiny little program: #include <windows.h> #include <shellapi.h> int __cdecl main(int argc, char **argv) { if (argc == 3) { SHELLEXECUTEINFO sei = { sizeof(sei) }; sei.fMask = SEE_MASK_FLAG_DDEWAIT; sei.nShow = SW_SHOWNORMAL; // added 27 Nov sei.lpVerb = argv[1]; sei.lpFile = argv[2]; ...

Why can’t you drop directly onto a taskbar button?

November 24, 2004 Nov 24, 2004 11/24/04
Raymond Chen
If you drag a object and drop it onto a taskbar button, you get an error message that says, You cannot drop an item onto a button on the taskbar. However, if you drag the item over a button without releasing the mouse button, the window will open after a moment, allowing you to drop the item inside the window. Why doesn't the taskbar ...

Why do folders like “My Pictures” come back after I delete them?

November 23, 2004 Nov 23, 2004 11/23/04
Raymond Chen
Some people are offended by the special folders like "My Pictures" and "My Music" and delete them, only to find them being re-created. What's going on? Windows itself is okay with you deleting those folders. Some corporations, for example, remove those folders from their employees' machines because they don't want the employees looking at ...

When people ask for security holes as features: World-writable files

November 22, 2004 Nov 22, 2004 11/22/04
Raymond Chen
If I had a nickel each time somebody asked for a feature that was a security hole... I'd have a lot of nickels. For example, "I want a file that all users can write to. My program will use it as a common database of goodies." This is a security hole. For a start, there's an obvious denial of service attack by having a user open the ...

The various ways of sending a message

November 19, 2004 Nov 19, 2004 11/19/04
Raymond Chen
There are several variations on the SendMessage function, but some are special cases of others. The simplest version is SendMessage itself, which sends a message and waits indefinitely for the response. The next level up is SendMessageTimeout which sends a message and waits for the response or until a certain amount of time has elapsed...

Am I sorry or not?

November 18, 2004 Nov 18, 2004 11/18/04
Raymond Chen
One of the consequences of the New Internet World Order is that it is very easy to set up a web site like www.sorryeverybody.com and equally easy to set up a response like www.notsorryeverybody.com. This state of affairs clearly calls out for some sort of competition between the two. At dinner last night, someone suggested that there should ...