Ah, this is Aegis. I used Aegis in the mid-80s (with Cadre Teamware). I moved on to SunOS and hadn't realized it was renamed to Domain OS.
Thanks, Alan ----- Original Message ----- Richard L. Hamilton <rlhamil at smart.net> wrote: >> > Is this intended to be something like the >> conditional symbolic links that have >> > been in Apollo Domain system 23 years ago? >> > >> >> I'm not familiar with that proposal. Can you provide >> details? >> >> Thanks, >> >> Alan > > As I recall, Apollo Domain OS implicitly made environment variables > available > to "system calls" (the quotation marks being because the OS was different > enough > that traditional system calls might often have been implemented more in user > space than is typical on the historical Unix code-base). Therefore, > symlinks > on Domain OS could contain environment variable references; I think these > looked > like $(name); so they might have symlinks like > > /usr -> /$(SYSTYPE)/usr > > where SYSTYPE could be sys5.3 or bsd4.3. (give or take details, I recall > that as an > actual example) > > Of course, Apollo also did some other odd things with path names: > > //nodename > > referred to the / direcctory of node nodename, as seen by other nodes > (similar to AFS /afs/node, or automounter /net/node) > > `node_data > > referred to the per-node private data directory (/sys/node_data on a diskful > node, something like /sys/node_data.nodeid on the diskful partner of > diskless node nodeid) > > And Apollo had a "typed" filesystem, where types for device files, symlinks, > FIFOs, > Unix-domain sockets, and unstructured files were only _some_ of the types; > others > could be for record-oriented files, windowing system entities (scrolling > back through > a transcript pad with mixed text and graphics would replay the graphics! - a > "terminal" > based on such a transcript pad was effectively seekable, but append-only for > writing), > files that incorporated revision history (the ancestor of Rational Rose), > etc. > In some cases, something that was not a directory could be other than the > last > level of a path name, in which case it would be up to the object at that > level > to interpret the "residue" of the pathname. > > (They also had a form of ACLs long before those were commonplace on other > Unix-like OSs.) > > So while the Apollo was IMO a _brilliant_ example of what's possible, some > of what > it could do exceeds what would readily fit the Unix model (although it could > present > a very credible approximation of that model as a subset of what it could > do). And > thus, examples from an Apollo may be useful in terms of thinking about a > problem, > but could often not be reasonably implemented to look similar on a more > traditional > Unix-like OS. > > (way OT: ISTR one limitation on the Apollo: anything that was executable was > effectively also readable, due to some architectural constraint) > -- > This message posted from opensolaris.org > _______________________________________________ > opensolaris-arc mailing list > opensolaris-arc at opensolaris.org >
