SYNTAX HIGHLIGHTER BEGINS

Friday, March 30, 2007

Getting Multiple file extensions with Directory.GetFiles()

I was looking for a way to list the files in a folder with different extensions and I came across a solution that Andreas Kraus(http://www.sunlab.de) wrote. So I took that and modified it a little


public static string[] GetFiles(
string path,
string searchPattern)
{
string[] m_arExt = searchPattern.Split(';');

List<string> strFiles = new List<string>();
foreach(string filter in m_arExt)
{
strFiles.AddRange(
System.IO.Directory.GetFiles(path, filter));
}
return strFiles.ToArray();
}

Thanks Andreas.

5 comments:

Rob@IndraNet said...

Thank you for this code. I could have written it myself, but is sooomuch easier to take your copy ;-)

Shaune Donohue said...

I hear ya.

DenisD said...

Be careful that there may be duplicate files in the resulting list for search pattern such as .htm;.html. This is due to te way GetFiles processes 3 char extensions.

MSDN : "A searchPattern with a file extension of exactly three characters returns files having an extension of three or more characters..."

Shaune Donohue said...

Thanks Denis, you are absolutely correct.

Here is the comments from MSDN

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.


The following list shows the behavior of different lengths for the searchPattern parameter:

"*.abc" returns files having an extension of .abc, .abcd, .abcde, .abcdef, and so on.

"*.abcd" returns only files having an extension of .abcd.

"*.abcde" returns only files having an extension of .abcde.

"*.abcdef" returns only files having an extension of .abcdef.

Anonymous said...

Thanks a lot! That really helped.