System.IO.Directory.EnumerateDirectories Method

Returns an enumerable collection of directory names that match a search pattern in a specified path, and optionally searches subdirectories.

Syntax

public static IEnumerable<string> EnumerateDirectories (string path, string searchPattern, SearchOption searchOption)

Parameters

path
The relative or absolute path to the directory to search. This string is not case-sensitive.
searchPattern
The search string to match against the names of directories in path. This parameter can contain a combination of valid literal path and wildcard (* and ?) characters (see Remarks), but doesn't support regular expressions.
searchOption
One of the enumeration values that specifies whether the search operation should include only the current directory or should include all subdirectories.

Returns

An enumerable collection of the full names (including paths) for the directories in the directory specified by path and that match the specified search pattern and option.

Remarks

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)

Exactly 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 or absolute path information in 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 returned directory names are prefixed with the value you provided in the path parameter. For example, if you provide a relative path in the path parameter, the returned directory names will contain a relative path.

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

Requirements

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