Directory.GetFiles Method (String, String, SearchOption)
Returns the names of files (including their paths) that match the specified search pattern in the specified directory, using a value to determine whether to search subdirectories.
Assembly: mscorlib (in mscorlib.dll)
public static string GetFiles( string path, string searchPattern, SearchOption searchOption )
- Type: System.String
The relative or absolute path to the directory to search. This string is not case-sensitive.
- Type: System.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 (see Remarks), but doesn't support regular expressions.
- Type: System.IO.SearchOption
One of the enumeration values that specifies whether the search operation should include all subdirectories or only the current directory.
Return ValueType: System.String
An array of the full names (including paths) for the files in the specified directory that match the specified search pattern and option, or an empty array if no files are found.
path is a zero-length string, contains only white space, or contains one or more invalid characters. You can query for invalid characters with the GetInvalidPathChars method.
searchPattern does not contain a valid pattern.
path or searchpattern is null.
searchOption is not a valid SearchOption value.
The caller does not have the required permission.
The specified path is not found or is invalid (for example, it is on an unmapped drive).
The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters and file names must be less than 260 characters.
path is a file name.
A network error has occurred.
The returned file names are appended to the supplied parameter path and the order of the returned file names is not guaranteed; use the Sort() method if a specific sort order is required.
searchPattern can be a combination of literal and wildcard characters, but doesn't support regular expressions. The following wildcard specifiers are permitted in searchPattern.
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 DirectorySeparatorChar or AltDirectorySeparatorChar, nor can it contain any invalid characters. You can query for invalid characters by using the GetInvalidPathChars method.
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:
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.
Because this method checks against file names with both the 8.3 file name format and the long file name format, a search pattern similar to "*1*.txt" may return unexpected file names. For example, using a search pattern of "*1*.txt" returns "longfilename.txt" because the equivalent 8.3 file name format is "LONGFI~1.TXT".
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 file names include the full path.
The path parameter can specify relative or absolute path information. Relative path information is interpreted as relative to the current working directory. To obtain the current working directory, see GetCurrentDirectory.
The path parameter is not case-sensitive.
For a list of common I/O tasks, see Common I/O Tasks.