If a stream is writable, writing at the end of the stream expands the stream.
如果流是可写的，则在流的末尾写入将使该流扩展。
For example, in a typical NetBoot environment, only the user's home directory is writable.
比如，在一个特定的网络启动环境下，只有用户的主目录是何以修改的。
NOTE: it is mandatory for a Writable SD Card to support Security Protocol.
注意：它是可写的SD卡强制性支持的安全协议。
A file is not made writable until it is checked out.
一个文件在签出前是不会变为可写的。
A file is not made writable until it is checked out.
一个文件在签出前是不会变为可写的。
应用推荐