The Question is:
System service SYS$GETRMI in CXX program
returns bad parameter code (status = 20) for item code RMI$_MODES.
Yes, this item code is not listed in manual, but rmidef.h contains quantum of
codes and RMI$_MODES too.
Does work this option anyway ?
The Answer is :
The OpenVMS Wizard would expect you have answered your own question,
given both the lack of formal documentation for the itemcode and the
resulting SS$_BADPARAM behaviour of the sys$getrmi API.
There is an example of the modes information collection using an
older and undocumented API known as exe$getspi; see the *SPI* source
modules on the OpenVMS Freeware.
Materials, interfaces, and APIs that are not listed in the OpenVMS
documentation set and/or in the Software Product Description -- and
this includes the (undocumented) SPISHR interface and exe$getspi
mentioned above -- are not generally considered supported APIs.