Code: NSData *data = [[textBox text] dataUsingEncoding:NSUTF8StringEncoding]; [file writeToFile:<etc>]; I can write to files owned by user 'mobile', but not those owned by user 'root'. In other unix systems, I know from experience that root privileges are gained by the user using sudo or su, but I don't know how this would be done within an application. Any help would be appreciated. As I am clueless.. Please Register or Log in to view images Edit: The owner of these files cannot be changed, for various reasons.