As a starter on std::filesystem, this recipe is still fairly short and straightforward. We initialized a path object from a string that contains a filesystem path description. The std::filesystem::path class plays a very central role whenever we use the filesystem library because most of the functions and classes relate to it.

Using the filesystem::exists function, we were able to check if the path really exists. Up to that point, we could not be sure about that, because it is indeed possible to create path objects that do not relate to an existing filesystem object. exists just accepts a path instance and returns true if it really exists. The function is already able to determine itself if we gave it an absolute or a relative path, which makes it very comfortable to use.

Finally, we used filesystem::canonical on the directory in order to print it in normalized form.

path canonical(const path& p, const path& base = current_path());

canonical accepts a path and as an optional second argument, it accepts another path. The second path base is prepended to path p if p is a relative path. After doing that, canonical tries to remove any . and .. path indirections.

While printing, we used the .c_str() method on the canonicalized path. The reason for this is that the overload of operator<< for output streams surrounds paths with quotation marks, which we may not always want.