mishkin@apollo.UUCP.UUCP (07/10/86)
To follow up on my previous message about multi-valued links, it has been pointed out to me by several people that I didn't have my head screwed on quite right: The right way to look at the problem is in terms of added pathname syntax, not links and environment variable. E.g. the syntax "/a/{x,y,z}/b" might be chosen to mean "/a/x/b", "/a/y/b", and "/a/z/b". This syntax could be "hidden" inside either environment variables OR links, as one likes: $ v := "{x,y,z}" $ catf "/a/$(v)/b" $ crl l "{x,y,z}" $ catf "/a/l/b" One interesting note: given that under Unix, all characters (other than "/") are valid in pathname components, how upset are people likely to be at me taking even more reserved characters (i.e. the "{" "}", or whatever)? If I used a syntax like "/a/$((x,y,z))/b", I wouldn't be making matters much worse since we already reserved "$(...)" for environment variables. Of course, this looks horrible. -- Nat Mishkin Apollo Computer Inc. apollo!mishkin -------
dennis%cod@NOSC.ARPA.UUCP (07/11/86)
I'm not sure I agree that your change to pathname syntax is what is wanted. For instance, in the case where alternate links/filenames are used to provide network redundancy, the command $ catf //{node1,node2}/sys/help/ld.hlp should display only one of the files, probably with a preference for the version on node1, whereas in $ dlf work/{version1,version2}/junk I probably want to delete two files. The generalization of the original idea to modifications of pathname syntax sounds interesting, but I would think that it would require careful scrutiny to make sure all the ramifications were understood. Dennis Cottel Naval Ocean Systems Center, San Diego, CA 92152 (619) 225-2406 dennis@nosc.ARPA sdcsvax!noscvax!dennis