FileInfo.SetAccessControl(FileSecurity) Method

Reference

Definition

Namespace:: System.IO

Assembly:: mscorlib.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Applies access control list (ACL) entries described by a FileSecurity object to the file described by the current FileInfo object.

public:
 void SetAccessControl(System::Security::AccessControl::FileSecurity ^ fileSecurity);

public void SetAccessControl (System.Security.AccessControl.FileSecurity fileSecurity);

member this.SetAccessControl : System.Security.AccessControl.FileSecurity -> unit

Public Sub SetAccessControl (fileSecurity As FileSecurity)

Parameters

fileSecurity: FileSecurity

A FileSecurity object that describes an access control list (ACL) entry to apply to the current file.

Exceptions

ArgumentNullException

The fileSecurity parameter is null.

SystemException

The file could not be found or modified.

UnauthorizedAccessException

The current process does not have access to open the file.

Examples

The following code example uses the GetAccessControl method and the SetAccessControl method to add and then remove an ACL entry from a file. You must supply a valid user or group account to run this example.

#using <System.Security.dll>
using namespace System;
using namespace System::IO;
using namespace System::Security::AccessControl;
using namespace System::Security::Principal;

// Adds an ACL entry on the specified file for the specified account.
static void AddFileSecurity(String^ fileName, String^ account,
                     FileSystemRights^ rights, 
                     AccessControlType^ controlType)
{
    // Create a new FileInfo object.
    FileInfo^ fInfo = gcnew FileInfo(fileName);
    if (!fInfo->Exists)
    {
        fInfo->Create();
    }

    // Get a FileSecurity object that represents the
    // current security settings.
    FileSecurity^ fSecurity = fInfo->GetAccessControl();

    // Add the FileSystemAccessRule to the security settings.
    fSecurity->AddAccessRule(gcnew FileSystemAccessRule(account,
        *rights, *controlType));

    // Set the new access settings.
    fInfo->SetAccessControl(fSecurity);
}

// Removes an ACL entry on the specified file for the specified account.
static void RemoveFileSecurity(String^ fileName, String^ account,
                        FileSystemRights^ rights, 
                        AccessControlType^ controlType)
{
    // Create a new FileInfo object.
    FileInfo^ fInfo = gcnew FileInfo(fileName);
    if (!fInfo->Exists)
    {
        fInfo->Create();
    }

    // Get a FileSecurity object that represents the
    // current security settings.
    FileSecurity^ fSecurity = fInfo->GetAccessControl();

    // Remove the FileSystemAccessRule from the security settings.
    fSecurity->RemoveAccessRule(gcnew FileSystemAccessRule(account, 
        *rights, *controlType));

    // Set the new access settings.
    fInfo->SetAccessControl(fSecurity);
}

int main()
{
    try
    {
        String^ fileName = "c:\\test.xml";

        Console::WriteLine("Adding access control entry for " +
            fileName);

        // Add the access control entry to the file.
        // Before compiling this snippet, change MyDomain to your 
        // domain name and MyAccessAccount to the name 
        // you use to access your domain.
        AddFileSecurity(fileName, "MyDomain\\MyAccessAccount",
            FileSystemRights::ReadData, AccessControlType::Allow);

        Console::WriteLine("Removing access control entry from " +
            fileName);

        // Remove the access control entry from the file.
        // Before compiling this snippet, change MyDomain to your 
        // domain name and MyAccessAccount to the name 
        // you use to access your domain.
        RemoveFileSecurity(fileName, "MyDomain\\MyAccessAccount",
            FileSystemRights::ReadData, AccessControlType::Allow);

        Console::WriteLine("Done.");
    }
    catch (Exception^ e)
    {
        Console::WriteLine(e);
    }

}
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//Adding access control entry for c:\test.xml
//Removing access control entry from c:\test.xml
//Done.
//

using System;
using System.IO;
using System.Security.AccessControl;

namespace FileSystemExample
{
    class FileExample
    {
        public static void Main()
        {
            try
            {
                string FileName = "c:/test.xml";

                Console.WriteLine("Adding access control entry for " + FileName);

                // Add the access control entry to the file.
                // Before compiling this snippet, change MyDomain to your
                // domain name and MyAccessAccount to the name
                // you use to access your domain.
                AddFileSecurity(FileName, @"MyDomain\MyAccessAccount", FileSystemRights.ReadData, AccessControlType.Allow);

                Console.WriteLine("Removing access control entry from " + FileName);

                // Remove the access control entry from the file.
                // Before compiling this snippet, change MyDomain to your
                // domain name and MyAccessAccount to the name
                // you use to access your domain.
                RemoveFileSecurity(FileName, @"MyDomain\MyAccessAccount", FileSystemRights.ReadData, AccessControlType.Allow);

                Console.WriteLine("Done.");
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
            }
        }

        // Adds an ACL entry on the specified file for the specified account.
        public static void AddFileSecurity(string FileName, string Account, FileSystemRights Rights, AccessControlType ControlType)
        {
            // Create a new FileInfo object.
            FileInfo fInfo = new FileInfo(FileName);

            // Get a FileSecurity object that represents the
            // current security settings.
            FileSecurity fSecurity = fInfo.GetAccessControl();

            // Add the FileSystemAccessRule to the security settings.
            fSecurity.AddAccessRule(new FileSystemAccessRule(Account,
                                                            Rights,
                                                            ControlType));

            // Set the new access settings.
            fInfo.SetAccessControl(fSecurity);
        }

        // Removes an ACL entry on the specified file for the specified account.
        public static void RemoveFileSecurity(string FileName, string Account, FileSystemRights Rights, AccessControlType ControlType)
        {
            // Create a new FileInfo object.
            FileInfo fInfo = new FileInfo(FileName);

            // Get a FileSecurity object that represents the
            // current security settings.
            FileSecurity fSecurity = fInfo.GetAccessControl();

            // Add the FileSystemAccessRule to the security settings.
            fSecurity.RemoveAccessRule(new FileSystemAccessRule(Account,
                                                            Rights,
                                                            ControlType));

            // Set the new access settings.
            fInfo.SetAccessControl(fSecurity);
        }
    }
}
//This code produces output similar to the following;
//results may vary based on the computer/file structure/etc.:
//
//Adding access control entry for c:\test.xml
//Removing access control entry from c:\test.xml
//Done.
//

Imports System.IO
Imports System.Security.AccessControl



Module FileExample

    Sub Main()
        Try
            Dim FileName As String = "c:\test.xml"

            Console.WriteLine("Adding access control entry for " & FileName)

            ' Add the access control entry to the file.
            ' Before compiling this snippet, change MyDomain to your 
            ' domain name and MyAccessAccount to the name 
            ' you use to access your domain.
            AddFileSecurity(FileName, "MyDomain\\MyAccessAccount", FileSystemRights.ReadData, AccessControlType.Allow)

            Console.WriteLine("Removing access control entry from " & FileName)

            ' Remove the access control entry from the file.
            ' Before compiling this snippet, change MyDomain to your 
            ' domain name and MyAccessAccount to the name 
            ' you use to access your domain.
            RemoveFileSecurity(FileName, "MyDomain\\MyAccessAccount", FileSystemRights.ReadData, AccessControlType.Allow)

            Console.WriteLine("Done.")
        Catch e As Exception
            Console.WriteLine(e)
        End Try

    End Sub


    ' Adds an ACL entry on the specified file for the specified account.
    Sub AddFileSecurity(ByVal FileName As String, ByVal Account As String, ByVal Rights As FileSystemRights, ByVal ControlType As AccessControlType)
        ' Create a new FileInfo object.
        Dim fInfo As New FileInfo(FileName)

        ' Get a FileSecurity object that represents the 
        ' current security settings.
        Dim fSecurity As FileSecurity = fInfo.GetAccessControl()

        ' Add the FileSystemAccessRule to the security settings. 
        fSecurity.AddAccessRule(New FileSystemAccessRule(Account, Rights, ControlType))

        ' Set the new access settings.
        fInfo.SetAccessControl(fSecurity)

    End Sub


    ' Removes an ACL entry on the specified file for the specified account.
    Sub RemoveFileSecurity(ByVal FileName As String, ByVal Account As String, ByVal Rights As FileSystemRights, ByVal ControlType As AccessControlType)
        ' Create a new FileInfo object.
        Dim fInfo As New FileInfo(FileName)

        ' Get a FileSecurity object that represents the 
        ' current security settings.
        Dim fSecurity As FileSecurity = fInfo.GetAccessControl()

        ' Add the FileSystemAccessRule to the security settings. 
        fSecurity.RemoveAccessRule(New FileSystemAccessRule(Account, Rights, ControlType))

        ' Set the new access settings.
        fInfo.SetAccessControl(fSecurity)

    End Sub
End Module
'This code produces output similar to the following; 
'results may vary based on the computer/file structure/etc.:
'
'Adding access control entry for c:\test.xml
'Removing access control entry from c:\test.xml
'Done.
'

Remarks

The SetAccessControl method applies access control list (ACL) entries to the current file that represents the noninherited ACL list.

Use the SetAccessControl method whenever you need to add or remove ACL entries from a file.

Caution

The ACL specified for the fileSecurity parameter replaces the existing ACL for the file. To add permissions for a new user, use the GetAccessControl method to obtain the existing ACL, modify it, and then use SetAccessControl to apply it back to the file.

An ACL describes individuals and/or groups who have, or do not have, rights to specific actions on the given file. For more information, see How to: Add or Remove Access Control List Entries.

The SetAccessControl method persists only FileSecurity objects that have been modified after object creation. If a FileSecurity object has not been modified, it will not be persisted to a file. Therefore, it is not possible to retrieve a FileSecurity object from one file and reapply the same object to another file.

To copy ACL information from one file to another:

Use the GetAccessControl method to retrieve the FileSecurity object from the source file.
Create a new FileSecurity object for the destination file.
Use the GetSecurityDescriptorBinaryForm or GetSecurityDescriptorSddlForm method of the source FileSecurity object to retrieve the ACL information.
Use the SetSecurityDescriptorBinaryForm or SetSecurityDescriptorSddlForm method to copy the information retrieved in step 3 to the destination FileSecurity object.
Set the destination FileSecurity object to the destination file using the SetAccessControl method.

Applies to