searchPattern can be a combination of literal and wildcard characters, but doesn't support regular expressions. The following wildcard specifiers are permitted in searchPattern..

* (asterisk)	Zero or more characters in that position.
? (question mark)	Zero or one character in that position.

Characters other than the wildcard are literal characters. For example, the searchPattern string "*t" searches for all names in path ending with the letter "t". The searchPattern string "s*" searches for all names in path beginning with the letter "s".

searchPattern cannot end in two periods ("..") or contain two periods ("..") followed by Path.DirectorySeparatorChar or Path.AltDirectorySeparatorChar, nor can it contain any invalid characters. You can query for invalid characters by using the Path.GetInvalidPathChars method.

You can specify relative path information with the path parameter. Relative path information is interpreted as relative to the current working directory, which you can determine by using the Directory.GetCurrentDirectory method.

The erload:System.IO.Directory.EnumerateFileSystemEntries and erload:System.IO.Directory.GetFileSystemEntries methods differ as follows: When you use erload:System.IO.Directory.EnumerateFileSystemEntries, you can start enumerating the collection of entries before the whole collection is returned; when you use erload:System.IO.Directory.GetFileSystemEntries, you must wait for the whole array of entries to be returned before you can access the array. Therefore, when you are working with many files and directories, erload:System.IO.Directory.EnumerateFiles can be more efficient.

The returned collection is not cached; each call to the IEnumerable`1.GetEnumerator on the collection will start a new enumeration.

Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 4.0.0.0