fs.readdir(path[, options], callback)

    读取目录的内容。 回调有两个参数 (err, files),其中 files 是目录中文件名的数组,不包括 '.''..'

    Reads the contents of a directory. The callback gets two arguments (err, files) where files is an array of the names of the files in the directory excluding '.' and '..'.

    See the POSIX readdir(3) documentation for more details.

    The optional options argument can be a string specifying an encoding, or an object with an encoding property specifying the character encoding to use for the filenames passed to the callback. If the encoding is set to 'buffer', the filenames returned will be passed as <Buffer> objects.

    If options.withFileTypes is set to true, the files array will contain <fs.Dirent> objects.