Function fdio::open_fd_at

pub fn open_fd_at(
    dir: &File,
    path: &str,
    flags: OpenFlags
) -> Result<File, Status>

Opens the remote object at the given path relative to the given dir with the given flags synchronously, and on success, binds that channel to a file descriptor and returns it.

dir must be backed by a directory protocol channel (even though it is wrapped in a std::fs::File).

Wraps fdio_open_fd_at.