如何获得相对路径的根目录

Question

I need to extract the name first of the first directory in a relative path.

I know I can go about:

relPath := "a/b/c/file.so"
splitPath := strings.Split(relPath, string(os.PathSeparator))
rootDirName := splitPath[0]

Is there a better way?

Answer 1

If you're asking whether there is way to do it with 1 standard Go function: not that I know of.

An alternative way would be:

relPath := "a/b/c/file.so"
i := strings.Index(relPath, string(os.PathSeparator))
rootDirName := relPath[:i]

Or if it is possible that the path contains no / at all:

relPath := "a/b/c/file.so"
i := strings.Index(relPath, string(os.PathSeparator))
rootDirName := ""
if i != -1 {
    rootDirName = relPath[:i]
}         

This has the benefit of not having to split the whole string and might, therefore, be a little faster on long paths.