Directory.EnumerateDirectories Method

Definition

Returns an enumerable collection of directory full names that meet specified criteria.

Overloads

EnumerateDirectories(String)

Returns an enumerable collection of directory full names in a specified path.

EnumerateDirectories(String, String)

Returns an enumerable collection of directory full names that match a search pattern in a specified path.

EnumerateDirectories(String, String, EnumerationOptions)

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

EnumerateDirectories(String, String, SearchOption)

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

EnumerateDirectories(String)

Source:
Directory.cs
Source:
Directory.cs
Source:
Directory.cs

Returns an enumerable collection of directory full names in a specified path.

public static System.Collections.Generic.IEnumerable<string> EnumerateDirectories (string path);

Parameters

path
String

The relative or absolute path to the directory to search. This string is not case-sensitive.

Returns

An enumerable collection of the full names (including paths) for the directories in the directory specified by path.

Exceptions

.NET Framework and .NET Core versions older than 2.1: path is a zero-length string, contains only white space, or contains invalid characters. You can query for invalid characters by using the GetInvalidPathChars() method.

path is null.

path is invalid, such as referring to an unmapped drive.

path is a file name.

The specified path, file name, or combined exceed the system-defined maximum length.

The caller does not have the required permission.

The caller does not have the required permission.

Examples

The following example enumerates the top-level directories in a specified path.

using System;
using System.Collections.Generic;
using System.IO;

class Program
{
    private static void Main(string[] args)
    {
        try
        {
            // Set a variable to the My Documents path.
            string docPath = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);

            List<string> dirs = new List<string>(Directory.EnumerateDirectories(docPath));

            foreach (var dir in dirs)
            {
                Console.WriteLine($"{dir.Substring(dir.LastIndexOf(Path.DirectorySeparatorChar) + 1)}");
            }
            Console.WriteLine($"{dirs.Count} directories found.");
        }
        catch (UnauthorizedAccessException ex)
        {
            Console.WriteLine(ex.Message);
        }
        catch (PathTooLongException ex)
        {
            Console.WriteLine(ex.Message);
        }
    }
}

Remarks

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 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 EnumerateDirectories and GetDirectories methods differ as follows: When you use EnumerateDirectories, you can start enumerating the collection of names before the whole collection is returned; when you use 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, EnumerateDirectories can be more efficient.

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

Applies to

.NET 9 and other versions
Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 1.3, 1.4, 1.6, 2.0, 2.1
UWP 10.0

EnumerateDirectories(String, String)

Source:
Directory.cs
Source:
Directory.cs
Source:
Directory.cs

Returns an enumerable collection of directory full names that match a search pattern in a specified path.

public static System.Collections.Generic.IEnumerable<string> EnumerateDirectories (string path, string searchPattern);

Parameters

path
String

The relative or absolute path to the directory to search. This string is not case-sensitive.

searchPattern
String

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, but it doesn't support regular expressions.

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.

Exceptions

.NET Framework and .NET Core versions older than 2.1: path is a zero-length string, contains only white space, or contains invalid characters. You can query for invalid characters with the GetInvalidPathChars() method.

-or-

searchPattern does not contain a valid pattern.

path is null.

-or-

searchPattern is null.

path is invalid, such as referring to an unmapped drive.

path is a file name.

The specified path, file name, or combined exceed the system-defined maximum length.

The caller does not have the required permission.

The caller does not have the required permission.

Examples

The following example enumerates the top-level directories in a specified path that match a specified search pattern.

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

class Program
{

    private static void Main(string[] args)
    {
        try
        {
            string dirPath = @"\\archives\2009\reports";

            // LINQ query.
            var dirs = from dir in
                     Directory.EnumerateDirectories(dirPath, "dv_*")
                       select dir;

            // Show results.
            foreach (var dir in dirs)
            {
                // Remove path information from string.
                Console.WriteLine("{0}",
                    dir.Substring(dir.LastIndexOf("\\") + 1));
            }
            Console.WriteLine("{0} directories found.",
                dirs.Count<string>().ToString());

            // Optionally create a List collection.
            List<string> workDirs = new List<string>(dirs);
        }
        catch (UnauthorizedAccessException UAEx)
        {
            Console.WriteLine(UAEx.Message);
        }
        catch (PathTooLongException PathEx)
        {
            Console.WriteLine(PathEx.Message);
        }
    }
}

Remarks

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

Wildcard specifier Matches
* (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 DirectorySeparatorChar or AltDirectorySeparatorChar, nor can it contain any invalid characters. You can query for invalid characters by using the 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 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 EnumerateDirectories and GetDirectories methods differ as follows: When you use EnumerateDirectories, you can start enumerating the collection of names before the whole collection is returned; when you use 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, EnumerateDirectories can be more efficient.

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

Applies to

.NET 9 and other versions
Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 1.3, 1.4, 1.6, 2.0, 2.1
UWP 10.0

EnumerateDirectories(String, String, EnumerationOptions)

Source:
Directory.cs
Source:
Directory.cs
Source:
Directory.cs

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

public static System.Collections.Generic.IEnumerable<string> EnumerateDirectories (string path, string searchPattern, System.IO.EnumerationOptions enumerationOptions);

Parameters

path
String

The relative or absolute path to the directory to search. This string is not case-sensitive.

searchPattern
String

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, but it doesn't support regular expressions.

enumerationOptions
EnumerationOptions

An object that describes the search and enumeration configuration to use.

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 enumeration options.

Exceptions

.NET Framework and .NET Core versions older than 2.1: path is a zero-length string, contains only white space, or contains invalid characters. You can query for invalid characters by using the GetInvalidPathChars() method.

-or-

searchPattern does not contain a valid pattern.

path or searchPattern is null.

searchOption is not a valid SearchOption value.

path is invalid, such as referring to an unmapped drive.

path is a file name.

The specified path, file name, or combined exceed the system-defined maximum length.

The caller does not have the required permission.

The caller does not have the required permission.

Remarks

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

Wildcard specifier Matches
* (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 DirectorySeparatorChar or AltDirectorySeparatorChar, nor can it contain any invalid characters. You can query for invalid characters by using the 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 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 EnumerateDirectories and GetDirectories methods differ as follows: When you use EnumerateDirectories, you can start enumerating the collection of names before the whole collection is returned; when you use 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, EnumerateDirectories can be more efficient.

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

Applies to

.NET 9 and other versions
Product Versions
.NET Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Standard 2.1

EnumerateDirectories(String, String, SearchOption)

Source:
Directory.cs
Source:
Directory.cs
Source:
Directory.cs

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

public static System.Collections.Generic.IEnumerable<string> EnumerateDirectories (string path, string searchPattern, System.IO.SearchOption searchOption);

Parameters

path
String

The relative or absolute path to the directory to search. This string is not case-sensitive.

searchPattern
String

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, but it doesn't support regular expressions.

searchOption
SearchOption

One of the enumeration values that specifies whether the search operation should include only the current directory or should include all subdirectories. The default value is TopDirectoryOnly.

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 search option.

Exceptions

.NET Framework and .NET Core versions older than 2.1: path is a zero-length string, contains only white space, or contains invalid characters. You can query for invalid characters by using the GetInvalidPathChars() method.

-or-

searchPattern does not contain a valid pattern.

path is null.

-or-

searchPattern is null.

searchOption is not a valid SearchOption value.

path is invalid, such as referring to an unmapped drive.

path is a file name.

The specified path, file name, or combined exceed the system-defined maximum length.

The caller does not have the required permission.

The caller does not have the required permission.

Examples

The following example enumerates directories in a specified path that match a specified search pattern. It uses the searchOption parameter to specify that all subdirectories should be included in the search.

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

class Program
{

    private static void Main(string[] args)
    {
        try
        {
            string dirPath = @"\\archives\2009\reports";

            // LINQ query.
            var dirs = from dir in
                     Directory.EnumerateDirectories(dirPath, "dv_*",
                        SearchOption.AllDirectories)
                       select dir;

            // Show results.
            foreach (var dir in dirs)
            {
                // Remove path information from string.
                Console.WriteLine("{0}",
                    dir.Substring(dir.LastIndexOf("\\") + 1));
            }
            Console.WriteLine("{0} directories found.",
                dirs.Count<string>().ToString());

            // Optionally create a List collection.
            List<string> workDirs = new List<string>(dirs);
        }
        catch (UnauthorizedAccessException UAEx)
        {
            Console.WriteLine(UAEx.Message);
        }
        catch (PathTooLongException PathEx)
        {
            Console.WriteLine(PathEx.Message);
        }
    }
}

Remarks

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

Wildcard specifier Matches
* (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 DirectorySeparatorChar or AltDirectorySeparatorChar, nor can it contain any invalid characters. You can query for invalid characters by using the 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 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 EnumerateDirectories and GetDirectories methods differ as follows: When you use EnumerateDirectories, you can start enumerating the collection of names before the whole collection is returned; when you use 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, EnumerateDirectories can be more efficient.

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

Applies to

.NET 9 and other versions
Product Versions
.NET Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9
.NET Framework 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard 1.3, 1.4, 1.6, 2.0, 2.1
UWP 10.0