I remember having this discussion about 30 years ago with a couple of the VMS
implementors. Im not going to argue with you - other thanks to say - at the end of the day
we decided just what I said -- there are pros/cons to each solution - you pointed out some
of the pros for logicals.
But reality is that what people use them for is pretty much the same and from a programmer
stand point - about the same amount of work to get the values.
I point out - that Cutler added to winders whatever he needed from VMS that did not really
support. He used env's since thats what they had -- they could have added them if
they had wanted too. But in fact what they already had a solution - yup it came from C
and UNIX but it was good enough.
As I said - its really an issue what is native for each system -- you should use that
solution of you can. I do not fault you for using logicals for a tool targeted to a
RSX or VMS. I'm just not going to grant that they really all that different.
As for a universal resolver vs having each client do a lot of work in the library, that
was and is an implementation choice - left over from how it was the original DNS was
implemented (at Berkeley on the VAX at the time). It is interesting that the UNIX idea
of a small program was sort of lost by many of my brethren at UCB when large address
spaces showed up.
I suspect that if the DNS had been written for PDP-11 UNIX it might have been a separate
process.
Clem
On Thu, Dec 19, 2013 at 6:18 PM, Johnny Billquist <bqt at softjar.se> wrote:
Hi.
On 2013-12-20 00:07, Clem Cole wrote:
logical names have a unix equiv. in environment variables.
Sortof, but not completely.
there are some differences and advantages to both but the idea and practice ends up being
the same IMO
I disagree.
what you are doing in resolve$foo could just as easily be put in the environment and get
the same result
No. Because I have (obviously) system wide logical names, which provides the system
defaults for this. Any user defined logical names will override the system ones.
This concept of having logical names on several levels (system, group, login, session,
task) do not have an equivalent form in Unix.
There are more aspects of environment variables that differs from logical names as well.
Which also is a part of the reason you don't use environment variables for some
things, and instead do have the small text files. (And I love small text files, by the
way, so don't misunderstand me.) It's just that in some situations, other
solutions can give a different bias, which might make some things easier.
that said you are correct that unix often used small txt files for some set up and
configuration but some programs used the env too. truth is sna files were used in some of
the dec OSes too - it was just a matter of taste.
I don't think one is better than the other -- I do think when in Rome I would want to
use the scheme that is the operational standard under the least astonishment principle
I'm not even going to get into an argument about which is better, or which thing was
done in different places. That is a totally different question.
Both ways work, they provide different pros and cons.
I just totally love the solution I have come up with for name resolving in RSX, which
allows me to easily solve some details which I have found very hard to do in a simple,
clean and nice way with the resolver solution that exists under Unix.
Johnny
Clem
On Dec 19, 2013, at 5:14 PM, Johnny Billquist <bqt at softjar.se> wrote:
On 2013-12-19 21:07, John Wilson wrote:
From: Johnny Billquist <bqt at softjar.se>
To get more on topic - I'm working on a name resolver for RSX right now.
It's a totally awesome thing, and I only wish Unix (or even VMS) had
something similar.
Me too! Port?
To Unix? Not likely. Logical names just don't have a good equivalent. The Unix way is
text files with configurations instead. But the form of that is already established, with
the /etc/resolv.conf and /etc/nsswitch.conf (and /etc/hosts) files. Hard to change, and
those do unfortunately not easily allow user overrides at any level.
(Now I just need to finish the DNS part of it.)
Details. Sounds like good engineering so far. Nice going!
Yeah. The DNS part is not really difficult. It's just a question of setting up and
sending out UDP packets, and then parsing the responses. Although I must admit that DNS
have some bits that I'm not too happy about.
Working on building the DNS query right now. That is actually really simple. Doing the
parsing will probably take a few days of work.
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
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