Why does DirectoryInfo.GetFiles() match files that don't match the mask?

Question

Basically, I have this code:

DirectoryInfo dir = new DirectoryInfo(@"\\MYNETWORK11\ABCDEFG\ABCDEFGHIJKL\00806\");
FileInfo[] files = dir.GetFiles("200810*");

I expect it to match any files starting with 200810. However, it's matching files named

20070618_00806.bak and 20070817_00806.bak (the stars aren't in the filename, that was the only way I could include the underscore)

I tried it with dir from a command prompt, and it matches those files also. Why?

Edit:

Maybe using C: as the example was not a good thing. The directory I'm actually querying is a network share \\MYNETWORK11\ABCDEFG\ABCDEFGHIJKL\00806\

If checking against the short name has anything to do with it, won't 20070817_00806.bak be 200708~1.bak? That doesn't match either

Answer 1

msdn states that

"Because this method checks against file names with both the 8.3 file name format and the long file name format, a search pattern similar to "*1*.txt" may return unexpected file names. For example, using a search pattern of "*1*.txt" will return "longfilename.txt" because the equivalent 8.3 file name format would be "longf~1.txt"."

Could this be the cause?

Answer 2

Try this from the command line:

dir /x 200810*

The "/x" will make it show the short filenames, as well as the long filenames. This would let you see whether the short filename actually does start with "200810".