perl -V:sh
sh='cmd /x /c';

##</code><code>##

D:\>perl -le"print `rmdir /?`"
rmdir: `/2': Invalid argument


D:\>perl -le"print `rmdir --help`"
Usage: rmdir [OPTION]... DIRECTORY...
Remove the DIRECTORY(ies), if they are empty.

      --ignore-fail-on-non-empty
                  ignore each failure that is solely because a directory
                  is non-empty
  -p, --parents   remove DIRECTORY, then try to remove each directory
                  component of that path name.  E.g., `rmdir -p a/b/c' is
                  similar to `rmdir a/b/c a/b a'.
  -v, --verbose   output a diagnostic for every directory processed
      --help     display this help and exit
      --version  output version information and exit

Report bugs to <bug-coreutils@gnu.org>.


D:\>perl -le"print `cmd /x /c rmdir /?`"
Removes (deletes) a directory.

RMDIR [/S] [/Q] [drive:]path
RD [/S] [/Q] [drive:]path

    /S      Removes all directories and files in the specified directory
            in addition to the directory itself.  Used to remove a directory
            tree.

    /Q      Quiet mode, do not ask if ok to remove a directory tree with /S