public void AddWriteRightsToEveryone(string filename)
{
// get sid of everyone group
SecurityIdentifier sid = new SecurityIdentifier(WellKnownSidType.WorldSid, null);
// create rule
FileSystemAccessRule rule = new FileSystemAccessRule(sid, FileSystemRights.Write, AccessControlType.Allow);
// get ACL of file
FileSecurity fsecurity = File.GetAccessControl(filename);
// modify ACL of file
fsecurity.Add(rule);
// apply modified ACL to file
File.SetAccessControl(fileName, fSecurity);
}
