Directory.EnumerateFileSystemEntries Method
Definition
Important
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Returns an enumerable collection of file-system entries that meet specified criteria.
Overloads
| EnumerateFileSystemEntries(String) |
Returns an enumerable collection of file names and directory names in a specified path. |
| EnumerateFileSystemEntries(String, String) |
Returns an enumerable collection of file names and directory names that match a search pattern in a specified path. |
| EnumerateFileSystemEntries(String, String, EnumerationOptions) |
Returns an enumerable collection of file names and directory names that match a search pattern and enumeration options in a specified path. |
| EnumerateFileSystemEntries(String, String, SearchOption) |
Returns an enumerable collection of file names and directory names that match a search pattern in a specified path, and optionally searches subdirectories. |
EnumerateFileSystemEntries(String)
- Source:
- Directory.cs
- Source:
- Directory.cs
- Source:
- Directory.cs
Returns an enumerable collection of file names and directory names in a specified path.
public:
static System::Collections::Generic::IEnumerable<System::String ^> ^ EnumerateFileSystemEntries(System::String ^ path);public static System.Collections.Generic.IEnumerable<string> EnumerateFileSystemEntries (string path);static member EnumerateFileSystemEntries : string -> seq<string>Public Shared Function EnumerateFileSystemEntries (path As String) As IEnumerable(Of String)Parameters
- path
- String
The relative or absolute path to the directory to search. This string is not case-sensitive.
Returns
An enumerable collection of file-system entries 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.
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 EnumerateFileSystemEntries and GetFileSystemEntries methods differ as follows: When you use EnumerateFileSystemEntries, you can start enumerating the collection of entries before the whole collection is returned; when you use 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, EnumerateFileSystemEntries 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
EnumerateFileSystemEntries(String, String)
- Source:
- Directory.cs
- Source:
- Directory.cs
- Source:
- Directory.cs
Returns an enumerable collection of file names and directory names that match a search pattern in a specified path.
public:
static System::Collections::Generic::IEnumerable<System::String ^> ^ EnumerateFileSystemEntries(System::String ^ path, System::String ^ searchPattern);public static System.Collections.Generic.IEnumerable<string> EnumerateFileSystemEntries (string path, string searchPattern);static member EnumerateFileSystemEntries : string * string -> seq<string>Public Shared Function EnumerateFileSystemEntries (path As String, searchPattern As String) As IEnumerable(Of String)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 file-system entries 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 file-system entries 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 by using the GetInvalidPathChars() method.
-or-
searchPattern does not contain a valid pattern.
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".
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 EnumerateFileSystemEntries and GetFileSystemEntries methods differ as follows: When you use EnumerateFileSystemEntries, you can start enumerating the collection of entries before the whole collection is returned; when you use 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, EnumerateFileSystemEntries 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
EnumerateFileSystemEntries(String, String, EnumerationOptions)
- Source:
- Directory.cs
- Source:
- Directory.cs
- Source:
- Directory.cs
Returns an enumerable collection of file names and directory names that match a search pattern and enumeration options in a specified path.
public:
static System::Collections::Generic::IEnumerable<System::String ^> ^ EnumerateFileSystemEntries(System::String ^ path, System::String ^ searchPattern, System::IO::EnumerationOptions ^ enumerationOptions);public static System.Collections.Generic.IEnumerable<string> EnumerateFileSystemEntries (string path, string searchPattern, System.IO.EnumerationOptions enumerationOptions);static member EnumerateFileSystemEntries : string * string * System.IO.EnumerationOptions -> seq<string>Public Shared Function EnumerateFileSystemEntries (path As String, searchPattern As String, enumerationOptions As EnumerationOptions) As IEnumerable(Of String)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 files and directories in path. This parameter can contain a combination of valid literal and wildcard 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 file-system entries in the directory specified by path, that match the specified search pattern and the specified 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.
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".
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 EnumerateFileSystemEntries and GetFileSystemEntries methods differ as follows: When you use EnumerateFileSystemEntries, you can start enumerating the collection of entries before the whole collection is returned; when you use 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, EnumerateFileSystemEntries 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
EnumerateFileSystemEntries(String, String, SearchOption)
- Source:
- Directory.cs
- Source:
- Directory.cs
- Source:
- Directory.cs
Returns an enumerable collection of file names and directory names that match a search pattern in a specified path, and optionally searches subdirectories.
public:
static System::Collections::Generic::IEnumerable<System::String ^> ^ EnumerateFileSystemEntries(System::String ^ path, System::String ^ searchPattern, System::IO::SearchOption searchOption);public static System.Collections.Generic.IEnumerable<string> EnumerateFileSystemEntries (string path, string searchPattern, System.IO.SearchOption searchOption);static member EnumerateFileSystemEntries : string * string * System.IO.SearchOption -> seq<string>Public Shared Function EnumerateFileSystemEntries (path As String, searchPattern As String, searchOption As SearchOption) As IEnumerable(Of String)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 file-system entries 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 file-system entries in the directory specified by path and that match the specified search pattern and 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.
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".
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 EnumerateFileSystemEntries and GetFileSystemEntries methods differ as follows: When you use EnumerateFileSystemEntries, you can start enumerating the collection of entries before the whole collection is returned; when you use 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, EnumerateFileSystemEntries can be more efficient.
The returned collection is not cached; each call to the GetEnumerator on the collection will start a new enumeration.
