like `/dev/console', will fill up your destination disk if you use it to copy `/dev/zero', will open unknown devices and have unknown
`/dev/zero' をコピーしようとしてコピー先ディスクを溢れさせたり、 - JM
Copyright (c) 2001 Robert Kiesling. Copyright (c) 2002, 2003 David Merrill. The contents of this document are licensed under the GNU Free Documentation License. Copyright (C) 1999 JM Project All rights reserved.