0                  Successful completion.
    -1                 Indicates an error. The function sets errno to
                       one of the following values:

                       o  EEXIST - The link named by path2 exists.

                       o  EFTYPE - Wildcards appear in either path1
                          or path2.

                       o  EINVAL - One or both arguments specify a
                          syntactically invalid pathname.

                       o  ENAMETOOLONG - The length of path1 or path2
                          exceeds PATH_MAX, or a pathname component
                          is longer than NAME_MAX.

                       o  EXDEV - The link named by path2 and
                          the filenamed by path1 are on different
                          devices.