x                  Upon successful completion, a pointer to the
                       resolved_name.
    NULL               Indicates an error. A null pointer is
                       returned, the contents of the buffer pointed
                       to by resolved_name are undefined, and errno
                       is set to indicate the error:

                       o  ENAMETOOLONG - The length of the file_name
                          argument exceeds PATH_MAX, or a pathname
                          component is longer than NAME_MAX.

                       o  ENOENT - A component of file_name does not
                          name an existing file, or file_name points
                          to an empty string.

                       o  Any errno value from chdir or stat.