committed with a minor tweak Thanks!
>
> Do I miss something simpler?
>
> Index: bin/rm/rm.1
> ===================================================================
> RCS file: /var/cvs/src/bin/rm/rm.1,v
> retrieving revision 1.37
> diff -u -p -r1.37 rm.1
> --- bin/rm/rm.1 25 May 2014 19:07:36 -0000 1.37
> +++ bin/rm/rm.1 22 Aug 2015 21:49:02 -0000
> @@ -102,6 +102,7 @@ The
> utility removes symbolic links, not the files referenced by the links.
> .Pp
> It is an error to attempt to remove the files
> +.Dq / ,
> .Dq \&.
> or
> .Dq .. .
> Index: bin/rm/rm.c
> ===================================================================
> RCS file: /var/cvs/src/bin/rm/rm.c,v
> retrieving revision 1.30
> diff -u -p -r1.30 rm.c
> --- bin/rm/rm.c 16 Jan 2015 06:39:32 -0000 1.30
> +++ bin/rm/rm.c 23 Aug 2015 11:52:28 -0000
> @@ -54,7 +54,7 @@ extern char *__progname;
> int dflag, eval, fflag, iflag, Pflag, stdin_ok;
>
> int check(char *, char *, struct stat *);
> -void checkdot(char **);
> +void checkdotorslash(char **);
> void rm_file(char **);
> int rm_overwrite(char *, struct stat *);
> int pass(int, off_t, char *, size_t);
> @@ -105,7 +105,7 @@ main(int argc, char *argv[])
> if (argc < 1 && fflag == 0)
> usage();
>
> - checkdot(argv);
> + checkdotorslash(argv);
>
> if (*argv) {
> stdin_ok = isatty(STDIN_FILENO);
> @@ -383,12 +383,12 @@ check(char *path, char *name, struct sta
> */
> #define ISDOT(a) ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' &&
> !(a)[2])))
> void
> -checkdot(char **argv)
> +checkdotorslash(char **argv)
> {
> char *p, **save, **t;
> - int complained;
> + int dotcomplained, slashcomplained;
>
> - complained = 0;
> + dotcomplained = slashcomplained = 0;
> for (t = argv; *t;) {
> /* strip trailing slashes */
> p = strrchr (*t, '\0');
> @@ -402,14 +402,20 @@ checkdot(char **argv)
> p = *t;
>
> if (ISDOT(p)) {
> - if (!complained++)
> + if (!dotcomplained++)
> warnx("\".\" and \"..\" may not be removed");
> - eval = 1;
> - for (save = t; (t[0] = t[1]) != NULL; ++t)
> - continue;
> - t = save;
> - } else
> + } else if (*p == '\0') {
> + if (!slashcomplained++)
> + warnx("\"/\" may not be removed");
> + } else {
> ++t;
> + continue;
> + }
> +
> + eval = 1;
> + for (save = t; (t[0] = t[1]) != NULL; ++t)
> + continue;
> + t = save;
> }
> }
>
>
