Hi Paul,
> + if (S_ISLNK (st.st_mode))
> + {
> + close (fd);
> + errno = EOPNOTSUPP;
> + return -1;
> + }Why EOPNOTSUPP? Why not ENOTSUP? On Solaris, gnulib's lchmod on a symbolic link produces lchmod: Operation not supported on transport endpoint "transport endpoint" is misleading. Likewise, in POSIX [1] EOPNOTSUPP means "Operation not supported on socket". I would find ENOTSUP a better choice. Bruno [1] https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html
