Path.GetInvalidFileNameChars Method

Definition

Namespace:

System.IO

Assembly:

System.Runtime.dll

Source:

Path.Unix.cs

Gets an array containing the characters that are not allowed in file names.

public:
 static cli::array <char> ^ GetInvalidFileNameChars();

public static char[] GetInvalidFileNameChars ();

static member GetInvalidFileNameChars : unit -> char[]

Public Shared Function GetInvalidFileNameChars () As Char()

Returns

Char[]

An array containing the characters that are not allowed in file names.

Examples

The following example demonstrates the GetInvalidFileNameChars method and the GetInvalidPathChars method to retrieve invalid characters.

using namespace System;
using namespace System::IO;

namespace PathExample
{
    public ref class GetCharExample
    {
    public:
        static void Main()
        {
            // Get a list of invalid path characters.
            array<Char>^ invalidPathChars = Path::GetInvalidPathChars();

            Console::WriteLine("The following characters are invalid in a path:");
            ShowChars(invalidPathChars);
            Console::WriteLine();

            // Get a list of invalid file characters.
            array<Char>^ invalidFileChars = Path::GetInvalidFileNameChars();

            Console::WriteLine("The following characters are invalid in a filename:");
            ShowChars(invalidFileChars);
        }

        static void ShowChars(array<Char>^ charArray)
        {
            Console::WriteLine("Char\tHex Value");
            // Display each invalid character to the console.
            for each (Char someChar in charArray)
            {
                if (Char::IsWhiteSpace(someChar))
                {
                    Console::WriteLine(",\t{0:X4}", (Int16)someChar);
                }
                else
                {
                    Console::WriteLine("{0:c},\t{1:X4}", someChar, (Int16)someChar);
                }
            }
        }
    };
};

int main()
{
    PathExample::GetCharExample::Main();
}
// Note: Some characters may not be displayable on the console.
// The output will look something like:
//
// The following characters are invalid in a path:
// Char    Hex Value
// ",      0022
// <,      003C
// >,      003E
// |,      007C
// ...
//
// The following characters are invalid in a filename:
// Char    Hex Value
// ",      0022
// <,      003C
// >,      003E
// |,      007C
// ...

using System;
using System.IO;

namespace PathExample
{
    class GetCharExample
    {
        public static void Main()
        {
            // Get a list of invalid path characters.
            char[] invalidPathChars = Path.GetInvalidPathChars();

            Console.WriteLine("The following characters are invalid in a path:");
            ShowChars(invalidPathChars);
            Console.WriteLine();

            // Get a list of invalid file characters.
            char[] invalidFileChars = Path.GetInvalidFileNameChars();

            Console.WriteLine("The following characters are invalid in a filename:");
            ShowChars(invalidFileChars);
        }

        public static void ShowChars(char[] charArray)
        {
            Console.WriteLine("Char\tHex Value");
            // Display each invalid character to the console.
            foreach (char someChar in charArray)
            {
                if (Char.IsWhiteSpace(someChar))
                {
                    Console.WriteLine(",\t{0:X4}", (int)someChar);
                }
                else
                {
                    Console.WriteLine("{0:c},\t{1:X4}", someChar, (int)someChar);
                }
            }
        }
    }
}
// Note: Some characters may not be displayable on the console.
// The output will look something like:
//
// The following characters are invalid in a path:
// Char    Hex Value
// ",      0022
// <,      003C
// >,      003E
// |,      007C
// ...
//
// The following characters are invalid in a filename:
// Char    Hex Value
// ",      0022
// <,      003C
// >,      003E
// |,      007C
// ...

Imports System.IO

Namespace PathExample
    Public Class GetCharExample
        Public Shared Sub Main()
            ' Get a list of invalid path characters.
            Dim invalidPathChars() As Char = Path.GetInvalidPathChars()

            Console.WriteLine("The following characters are invalid in a path:")
            ShowChars(invalidPathChars)
            Console.WriteLine()

            ' Get a list of invalid file characters.
            Dim invalidFileChars() As Char = Path.GetInvalidFileNameChars()

            Console.WriteLine("The following characters are invalid in a filename:")
            ShowChars(invalidFileChars)
        End Sub

        Public Shared Sub ShowChars(charArray As Char())
            Console.WriteLine("Char" + vbTab + "Hex Value")
            ' Display each invalid character to the console.
            For Each someChar As Char In charArray
                If Char.IsWhiteSpace(someChar)
                    Console.WriteLine("," + vbTab + "{0:X4}", _
                        Microsoft.VisualBasic.Asc(someChar))
                Else
                    Console.WriteLine("{0:c}," + vbTab +"{1:X4}", someChar, _
                        Microsoft.VisualBasic.Asc(someChar))
                End If
            Next someChar
        End Sub
    End Class
End Namespace
' Note: Some characters may not be displayable on the console.
' The output will look something like:
'
' The following characters are invalid in a path:
' Char    Hex Value
' ",      0022
' <,      003C
' >,      003E
' |,      007C
' ...
'
' The following characters are invalid in a filename:
' Char    Hex Value
' ",      0022
' <,      003C
' >,      003E
' |,      007C
' ...

Remarks

The array returned from this method is not guaranteed to contain the complete set of characters that are invalid in file and directory names. The full set of invalid characters can vary by file system. For example, on Windows-based desktop platforms, invalid path characters might include ASCII/Unicode characters 1 through 31, as well as quote ("), less than (<), greater than (>), pipe (|), backspace (\b), null (\0) and tab (\t).