Had to use the Directory.GetFiles() method in .NET, so I read the description. Now, take a moment and read the following about how an asterisk wildcard character works in the search pattern parameter. Then tell me if this description is of a feature or of a bug. Windows, largely due to legacy, is full of this crap.
When using the asterisk wildcard character in a searchPattern, such as “*.txt”, the matching behavior when the extension is exactly three characters long is different than when the extension is more or less than three characters long. A searchPattern with a file extension of exactly three characters returns files having an extension of three or more characters, where the first three characters match the file extension specified in the searchPattern. A searchPattern with a file extension of one, two, or more than three characters returns only files having extensions of exactly that length that match the file extension specified in the searchPattern. When using the question mark wildcard character, this method returns only files that match the specified file extension. For example, given two files, “file1.txt” and “file1.txtother”, in a directory, a search pattern of “file?.txt” returns just the first file, while a search pattern of “file*.txt” returns both files.
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” returns “longfilename.txt” because the equivalent 8.3 file format is “LONGFI~1.TXT”.
The conclusion must be that this function is worse than useless and bound to cause excruciating bugs in your apps. Better use the GetFiles() method without any search pattern and then filter using a regex.