Linked by Eugenia Loli on Mon 12th Jan 2004 05:21 UTC, submitted by Simon Strandgaard
OSNews, Generic OSes When new operating systems gets designed today, great systems such as Amiga, Atari and VMS, seems to get overlooked in regard to their original features not found on other OSes. It might be time to collect and categorize those special unique features under the great/lost ideas wiki, so new OSes don't have to re-invent the wheel and re-innovate.
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VMS - logicals aka environment variables on steroids
by Anonymous on Mon 12th Jan 2004 14:05 UTC

File versioning was the best VMS feature besides clustering. However, I think logicals are pretty cool.

In Unix, environment variables are all process-specific. In VMS, logicals act as environment variables. There are two types of logicals, SYSTEM and PROCESS.

SYSTEM logicals, as the name implies, are visible system-wide so that any process could potentially pick them up (assuming the process has the right privs). PROCESS logicals are similar to Unix environment variables in that they are specific to a particular process.

- For cluster system management, it is possible to change any system logical across your entire cluster without end-users having to do a thing. No re-login necessary. This is extremely useful.

- The file system can handle logicals directly, since logicals are part of the core OS rather than just part of the shell.
- A logical can point to a list of directories or files. This list of files or directories acts as a search path similar to the PATH variable, except much more generic.


IMHO, VMS logicals are environment variables done right.