Directory.EnumerateFiles Directory.EnumerateFiles Directory.EnumerateFiles Directory.EnumerateFiles Method

Definition

Returns an enumerable collection of file names that meet specified criteria.

Overloads

EnumerateFiles(String, String, EnumerationOptions) EnumerateFiles(String, String, EnumerationOptions) EnumerateFiles(String, String, EnumerationOptions)
EnumerateFiles(String, String, SearchOption) EnumerateFiles(String, String, SearchOption) EnumerateFiles(String, String, SearchOption)

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

EnumerateFiles(String) EnumerateFiles(String) EnumerateFiles(String) EnumerateFiles(String)

Returns an enumerable collection of file names in a specified path.

EnumerateFiles(String, String) EnumerateFiles(String, String) EnumerateFiles(String, String) EnumerateFiles(String, String)

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

EnumerateFiles(String, String, EnumerationOptions) EnumerateFiles(String, String, EnumerationOptions) EnumerateFiles(String, String, EnumerationOptions)

public:
 static System::Collections::Generic::IEnumerable<System::String ^> ^ EnumerateFiles(System::String ^ path, System::String ^ searchPattern, System::IO::EnumerationOptions ^ enumerationOptions);
public static System.Collections.Generic.IEnumerable<string> EnumerateFiles (string path, string searchPattern, System.IO.EnumerationOptions enumerationOptions);
static member EnumerateFiles : string * string * System.IO.EnumerationOptions -> seq<string>
Parameters
searchPattern
String String String String
Returns

EnumerateFiles(String, String, SearchOption) EnumerateFiles(String, String, SearchOption) EnumerateFiles(String, String, SearchOption)

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

public:
 static System::Collections::Generic::IEnumerable<System::String ^> ^ EnumerateFiles(System::String ^ path, System::String ^ searchPattern, System::IO::SearchOption searchOption);
public static System.Collections.Generic.IEnumerable<string> EnumerateFiles (string path, string searchPattern, System.IO.SearchOption searchOption);
static member EnumerateFiles : string * string * System.IO.SearchOption -> seq<string>
Parameters
path
String String String String

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

searchPattern
String String String String

The search string to match against the names of files 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 SearchOption 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 files in the directory specified by path and that match the specified search pattern and option.

Exceptions

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.

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

The caller does not have the required permission.

Examples

The following example shows how to retrieve all the text files in a directory and its subdirectories, and move them to a new directory. After the files are moved, they no longer exist in the original directories.

using System;
using System.IO;

namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            string sourceDirectory = @"C:\current";
            string archiveDirectory = @"C:\archive";

            try
            {
                var txtFiles = Directory.EnumerateFiles(sourceDirectory, "*.txt", SearchOption.AllDirectories);

                foreach (string currentFile in txtFiles)
                {
                    string fileName = currentFile.Substring(sourceDirectory.Length + 1);
                    Directory.Move(currentFile, Path.Combine(archiveDirectory, fileName));
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
        }
    }
}
Imports System.IO

Module Module1

    Sub Main()
        Dim sourceDirectory As String = "C:\current"
        Dim archiveDirectory As String = "C:\archive"

        Try
            Dim txtFiles = Directory.EnumerateFiles(sourceDirectory, "*.txt", SearchOption.AllDirectories)

            For Each currentFile As String In txtFiles
                Dim fileName = currentFile.Substring(sourceDirectory.Length + 1)
                Directory.Move(currentFile, Path.Combine(archiveDirectory, fileName))
            Next
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try

    End Sub

End Module

The following example recursively enumerates all files that have a .txt extension, reads each line of the file, and displays the line if it contains the string "Microsoft".

using System;
using System.IO;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        try
        {
            var files = from file in Directory.EnumerateFiles(@"c:\", "*.txt", SearchOption.AllDirectories)
                        from line in File.ReadLines(file)
                        where line.Contains("Microsoft")
                        select new
                        {
                            File = file,
                            Line = line
                        };

            foreach (var f in files)
            {
                Console.WriteLine("{0}\t{1}", f.File, f.Line);
            }
			Console.WriteLine("{0} files found.", files.Count().ToString());
        }
        catch (UnauthorizedAccessException UAEx)
        {
            Console.WriteLine(UAEx.Message);
        }
        catch (PathTooLongException PathEx)
        {
            Console.WriteLine(PathEx.Message);
        }
    }
}
Imports System.IO
Imports System.Xml.Linq
Module Module1

    Sub Main()
        Try
            Dim files = From chkFile In Directory.EnumerateFiles("c:\", "*.txt", SearchOption.AllDirectories)
                        From line In File.ReadLines(chkFile)
                        Where line.Contains("Microsoft")
                        Select New With {.curFile = chkFile, .curLine = line}

            For Each f In files
                Console.WriteLine("{0}\t{1}", f.curFile, f.curLine)
            Next
            Console.WriteLine("{0} files found.", files.Count.ToString())
        Catch UAEx As UnauthorizedAccessException
            Console.WriteLine(UAEx.Message)
        Catch PathEx As PathTooLongException
            Console.WriteLine(PathEx.Message)
        End Try
    End Sub
End Module

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) 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".

Note

When you use the asterisk wildcard character in a searchPattern such as "*.txt", the number of characters in the specified extension affects the search as follows:

  • If the specified extension is exactly three characters long, the method returns files with extensions that begin with the specified extension. For example, "*.xls" returns both "book.xls" and "book.xlsx".
    • In all other cases, the method returns files that exactly match the specified extension. For example, "*.ai" returns "file.ai" but not "file.aif".

When you use 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, whereas a search pattern of "file*.txt" returns both files.

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 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 GetCurrentDirectory method.

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

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

EnumerateFiles(String) EnumerateFiles(String) EnumerateFiles(String) EnumerateFiles(String)

Returns an enumerable collection of file names in a specified path.

public:
 static System::Collections::Generic::IEnumerable<System::String ^> ^ EnumerateFiles(System::String ^ path);
public static System.Collections.Generic.IEnumerable<string> EnumerateFiles (string path);
static member EnumerateFiles : string -> seq<string>
Public Shared Function EnumerateFiles (path As String) As IEnumerable(Of String)
Parameters
path
String String String 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 files in the directory specified by path.

Exceptions

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.

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

The caller does not have the required permission.

Examples

The following example shows how to retrieve all the files in a directory and move them to a new directory. After the files are moved, they no longer exist in the original directory.

using System;
using System.IO;

namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            string sourceDirectory = @"C:\current";
            string archiveDirectory = @"C:\archive";

            try
            {
                var txtFiles = Directory.EnumerateFiles(sourceDirectory);

                foreach (string currentFile in txtFiles)
                {
                    string fileName = currentFile.Substring(sourceDirectory.Length + 1);
                    Directory.Move(currentFile, Path.Combine(archiveDirectory, fileName));
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
        }
    }
}
Imports System.IO

Module Module1

    Sub Main()
        Dim sourceDirectory As String = "C:\current"
        Dim archiveDirectory As String = "C:\archive"

        Try
            Dim txtFiles = Directory.EnumerateFiles(sourceDirectory)

            For Each currentFile As String In txtFiles
                Dim fileName = currentFile.Substring(sourceDirectory.Length + 1)
                Directory.Move(currentFile, Path.Combine(archiveDirectory, fileName))
            Next
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try

    End Sub

End Module

The following example enumerates the files in the specified directory, reads each line of the file, and displays the line if it contains the string "Europe".

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

class Program
{
    static void Main(string[] args)
    {
        try
        {
            // LINQ query for all files containing the word 'Europe'.
            var files = from file in 
                Directory.EnumerateFiles(@"\\archives1\library\")
                where file.ToLower().Contains("europe")
                select file;

            foreach (var file in files)
            {
                Console.WriteLine("{0}", file);
            }
            Console.WriteLine("{0} files found.", files.Count<string>().ToString());
        }
        catch (UnauthorizedAccessException UAEx)
        {
            Console.WriteLine(UAEx.Message);
        }
        catch (PathTooLongException PathEx)
        {
            Console.WriteLine(PathEx.Message);
        }
    }
}
Imports System.IO
Imports System.Linq
Module Module1

    Sub Main()
        Try
            ' LINQ query for all files containing the word 'Europe'.
            Dim files = From file In Directory.EnumerateFiles("\\archives1\library\")
                Where file.ToLower().Contains("europe")

            For Each file In files
                Console.WriteLine("{0}", file)
            Next
            Console.WriteLine("{0} files found.", files.Count.ToString())
        Catch UAEx As UnauthorizedAccessException
            Console.WriteLine(UAEx.Message)
        Catch PathEx As PathTooLongException
            Console.WriteLine(PathEx.Message)
        End Try
    End Sub

End Module

Remarks

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 GetCurrentDirectory method.

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

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

EnumerateFiles(String, String) EnumerateFiles(String, String) EnumerateFiles(String, String) EnumerateFiles(String, String)

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

public:
 static System::Collections::Generic::IEnumerable<System::String ^> ^ EnumerateFiles(System::String ^ path, System::String ^ searchPattern);
public static System.Collections.Generic.IEnumerable<string> EnumerateFiles (string path, string searchPattern);
static member EnumerateFiles : string * string -> seq<string>
Public Shared Function EnumerateFiles (path As String, searchPattern As String) As IEnumerable(Of String)
Parameters
path
String String String String

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

searchPattern
String String String String

The search string to match against the names of files 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 files in the directory specified by path and that match the specified search pattern.

Exceptions

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.

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

The caller does not have the required permission.

Examples

The following example shows how to retrieve all the text files in a directory and move them to a new directory. After the files are moved, they no longer exist in the original directory.

using System;
using System.IO;

namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            string sourceDirectory = @"C:\current";
            string archiveDirectory = @"C:\archive";

            try
            {
                var txtFiles = Directory.EnumerateFiles(sourceDirectory, "*.txt");

                foreach (string currentFile in txtFiles)
                {
                    string fileName = currentFile.Substring(sourceDirectory.Length + 1);
                    Directory.Move(currentFile, Path.Combine(archiveDirectory, fileName));
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
        }
    }
}
Imports System.IO

Module Module1

    Sub Main()
        Dim sourceDirectory As String = "C:\current"
        Dim archiveDirectory As String = "C:\archive"

        Try
            Dim txtFiles = Directory.EnumerateFiles(sourceDirectory, "*.txt")

            For Each currentFile As String In txtFiles
                Dim fileName = currentFile.Substring(sourceDirectory.Length + 1)
                Directory.Move(currentFile, Path.Combine(archiveDirectory, fileName))
            Next
        Catch e As Exception
            Console.WriteLine(e.Message)
        End Try
    End Sub

End Module

The following example enumerates the files in the specified directory that have a .txt extension, reads each line of the file, and displays the line if it contains the string "Europe".

using System;
using System.Linq;
using System.IO;

class Program
{
    static void Main(string[] args)
    {
        try
        {
            // LINQ query for all .txt files containing the word 'Europe'.
            var files = from file in Directory.EnumerateFiles(@"\\archives1\library\", "*.txt")
                where file.ToLower().Contains("europe")
                select file;

            foreach (var file in files)
            {
                Console.WriteLine("{0}", file);
            }
            Console.WriteLine("{0} files found.", files.Count<string>().ToString());
        }
			
        catch (UnauthorizedAccessException UAEx)
        {
            Console.WriteLine(UAEx.Message);
        }
        catch (PathTooLongException PathEx)
        {
            Console.WriteLine(PathEx.Message);
        }
    }
}
Imports System.IO
Imports System.Linq
Module Module1

    Sub Main()
        Try
            ' LINQ query for all .txt files containing the word 'Europe'.
            Dim files = From file In Directory.EnumerateFiles("\\archives1\library\", "*.txt")
                Where file.ToLower().Contains("europe")

            For Each file In files
                Console.WriteLine("{0}", file)
            Next
            Console.WriteLine("{0} files found.", files.Count.ToString())
        Catch UAEx As UnauthorizedAccessException
            Console.WriteLine(UAEx.Message)
        Catch PathEx As PathTooLongException
            Console.WriteLine(PathEx.Message)
        End Try
    End Sub

End Module

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) 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".

Note

When you use the asterisk wildcard character in a searchPattern such as "*.txt", the number of characters in the specified extension affects the search as follows:

  • If the specified extension is exactly three characters long, the method returns files with extensions that begin with the specified extension. For example, "*.xls" returns both "book.xls" and "book.xlsx".
    • In all other cases, the method returns files that exactly match the specified extension. For example, "*.ai" returns "file.ai" but not "file.aif".

When you use 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, whereas a search pattern of "file*.txt" returns both files.

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 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 GetCurrentDirectory method.

The EnumerateFiles and GetFiles methods differ as follows: When you use EnumerateFiles, you can start enumerating the collection of names before the whole collection is returned; when you use GetFiles, 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, EnumerateFiles 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