If the type argument is left undefined, Node will autodetect target type and automatically select dir or file.
type
target
dir
file
The target and path parameters can be WHATWG URL objects using file: protocol. Support is currently still experimental.
path
URL
file:
新增于: v0.1.31
null
undefined
有关详细信息，请参阅此 API 异步版本的文档：fs.symlink()。
fs.symlink()
【For detailed information, see the documentation of the asynchronous version of this API: fs.symlink().】