func Dir(path string) string

Dir returns all but the last element of path,typically the path's directory. After dropping the final element using Split,the path is Cleaned and trailing slashes are removed. If the path is empty,Dir returns ".". If the path consists entirely of slashes followed by non-slash bytes,Dir returns a single slash. In any other case,the returned path does not end in a slash.

fmt.Println(path.Dir("/a/b/c"))

/a/b

这个函数属于path package中的一个，但是无法解析windows的反斜杠地址，比如：输入：

fmt.Println(path.Dir("c:\macs\leo\"))

输出为：.

一个dot号。

但是golang牛逼的地方在于：可以解析这样的地址：C:\golang\src\LBSIM-MVC2\src/conf/config.json，，哈哈 真是好用，不需要 我自己调用runtime.GOOS进行判断了。