The Old New Thing

Code - The Old New Thing

How do I find the most recently created file in a directory from a batch file?

August 1, 2012 Aug 1, 2012 08/1/12
Raymond Chen
We've reached Hump Day of Batch File Week. Remember, nobody actually likes batch programming. You merely tolerate it. Today, we'll find the most recently-created item in a directory. (For example, we have a server that holds our daily builds, and you might want to write a batch file that automatically installs the latest build.) There may...

Reading the output of a command into a batch file variable

July 31, 2012 Jul 31, 2012 07/31/12
Raymond Chen
It's Day Two of Batch File Week. Don't worry, it'll be over in a few days. There is no obvious way to read the output of a command into a batch file variable. In unix-style shells, this is done via backquoting. The Windows command processor does not have direct backquoting, but you can fake it by abusing the command. Here's the ...

Why don't any commands work after I run my batch file? I'm told that they are not recognized as an internal or external command, operable program, or batch file.

July 30, 2012 Jul 30, 2012 07/30/12
Raymond Chen
I sort of forgot to celebrate CLR Week last year, so let's say that CLR week is "on hiatus" until next year. To fill the summertime time slot, I'm going to burn off a busted pilot: This week is Batch File Week 2012. Remember, nobody actually enjoys batch programming. It's just something you have to put up with in order to get something done. ...

Psychic debugging: Why your IContextMenu::InvokeCommand never gets called

July 27, 2012 Jul 27, 2012 07/27/12
Raymond Chen
A customer reported a problem with their shell context menu extension. I have implemented the shell extension, but when the user selects my custom menu item, my is never called. Can anyone please let me know what the problem could be and how to fix it? Since there really isn't much information provided in this request, I was forced to ...

Why do some font names begin with an at-sign?

July 19, 2012 Jul 19, 2012 07/19/12
Raymond Chen
It was a simple question. For some reason, my font selection dialog () shows a bunch of font names beginning with the at-sign (@). These fonts don't work correctly if I use them. Any idea what they are? (I tried searching the Internet, but search engines don't seem to let you search for so it's hard to make much headway.) (And that's ...

Why doesn't RealGetWindowClass return the real window class for my superclass?

July 13, 2012 Jul 13, 2012 07/13/12
Raymond Chen
A customer was reporting that the function was not reporting the base window class of their superclass. (Error checking has been elided for expository purposes.) The customer found that the assertion fails, returning a window class name of "AwesomeWindow" instead of "static". "I thought the point of RealGetWindowClass was to dig through ...

What happens when you mark a section as DISCARDABLE?

July 12, 2012 Jul 12, 2012 07/12/12
Raymond Chen
In the flags you pass to the linker, you can specify that a section be made discardable. What does that mean? If you are a kernel-mode driver, the discardable flag means that the contents will be removed from memory after initialization is complete. This is where you put your initialization code and data. But if you're writing user-mode ...

How your taskbar auto-hide settings can keep getting overwritten

July 5, 2012 Jul 5, 2012 07/5/12
Raymond Chen
A customer reported that they were observing that some users were finding their taskbar set to auto-hide even though the standard configuration in the company is for the auto-hide feature to be disabled. Going into Taskbar Properties shows Auto-hide the taskbar checked. None of the users had changed their setting to auto-hide manually, so the ...