Return_Values

   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.