My opinion about VMS(es) systems.
VMS has been a very good OS. However, I think that it does not match
the characteristics of a modern OS.
What is good in VMS, IMNSHO:
- "Asynchronous system trap" mechanism that comes from RSX systems.
- Documentation.
What is questionnable in VMS, IMNSHO:
- DCL
This script language is very poor and looks like some prehistoric basic
language.
- RMS
I never saw application programmers happy to use this programming interface
in C language.
RMS programming interface is a major difficulty for application developpment
under VMS.
- Logical Names.
Logical Names tables apply to system resources and I think that they must not
be used for applicative ressources.
The system services have built-in rules for logical names translations that
implies that only system resources are named by logical names.
VMS logical names allow writing applications with hard wired resource names.
This hardwired resources names _must_ be system resources.
Very usefull for COBOL applications.
I think that Logical Names under VMS is not open enough for applications.
It is a poor facility.
What is good in Linux, IMHO:
The best operating system must be compatible with POSIX, BSD extensions, SVIDs,
Microsoft Systems, be portable, provide lots of hardware drivers, etc...
Existing systems are only compromises.
IMNSO, the best compromise is Linux.
I think that Linux is or is going to become the _best_ Operating System.
What is questionnable in Linux, IMHO:
Perhaps lots of things.
However, Linux is a very young OS and I prefer to wait and see prior making
my opinion.
Some unnecessary things for a modern OS, IMNSHO:
- About streams, I think that they are mandatory only for SYSV compatibility.
The most common used transport interface is the socket library.
The open transport interface on proprietary system _is_ a BSD socket like
interface (example: WINSOCKET).
On system V based system, the socket library is emulated above transport
stream heads. They generally are very bad emulations.
Try to write some complex applications with sockets under Solaris or SCO that
use SIGIO and select() and pray.
Proprietary system emulations other than some Microsoft things are indeed
unnecessary.
I stop my article without speaking about WNT (a VMS mutant), since it seems
to me that I am writing a book.
If that happen I will leave all the pages blank in order to be quite sure that
it will be a good buy. (twice).
Good bye.
Gerard.
PS:
Bill does not need "sys$get()" RMS system service in order to get dollars with
systems.
Linux+GNU+X11+Internet is the best Finnish recipe a French cook have ever tried.