Re: [Gnu-arch-users] Re: Tla spork

[James Blackwell]

[An algorithm that jblack wrote for using environment variables to set
roles.]

Tom Lord wrote:
> Sure but.... I guess what it comes down to is that environment-passed
> parameters are hard to control because they (by design) violate lots
> of abstraction boundaries.  Their usefulness is not 0 but it is very
> limited.
>
> Please don't junk up arch with crap that creates unfortunate
> surprises.

Tom, calm down. We're just having a brainstorming discussion. 

On the general issue (avoid environment variables), you and I are in
strong agreement. But I think this is the exception that proves the
rule. People such as myself are in different contexts in different ttys.

I'm frequently in the position in which I'm in one role on one tty, and
another role on another tty. I'll frequently do work on one tty, get
tired of the problem, and move to the other tty and pick up my work
there. 

Basically, my roles are tty based.  I like the idea of being able to on tty1
say "export ARCH_HAT=hacker" and on tty2 say "export ARCH_HAT=drone".
That way, my-ids are set, my default archive is right, so forth and so on.

The problem that we're trying to solve with roles doesn't really get
solved if every time I switch ttys, I have to remember to type tla
my-hat. 

If you ask me, not supporting an env variable does the exact opposite of
what you intend, by removing the ability to set a local context and
forcing a global one. 


On an unrelated note, here's a troll: s-exps are ugly, Ugly, UGLY.
They're wrong, man! 


Jblack wrote:
>     > I imagine it closer to the following (I'm playing loose with the code
>     > here): 
>     > 
>     > my_hat = 0
>     > 
>     > if ( valid_hat(getenv("ARCH_HAT")))
>     >     my_hat = get_env("ARCH_HAT")
>     > 
>     > if (! my_hat)
>     >   my_hat = get_arch_hat()
>     > 
>     > if (! my_hat)
>     >   my_hat = passed_hat
>     > 
>     > if (! my_hat)
>     >    panic("You're not wearing any hats!")
>     > 
>     > 
>     > bugs:
>     >   I don't think we'd have a problem here. Sure, if tla didn't
>     >   provide library support to look up the my-idish stuff, or if tla
>     >   was not using it consistantly, I'd agree. But tla does use the library
>     >   routines consistantly, so we don't need to worry about either bugs or
>     >   flakiness (a subset of bugs)
>     > 
>     > exploits: 
>     > I think that we're safe here because of the lack of statically defined
>     > buffers. Somebody thought ahead of that problem and wrote hackerlab.
>     > 
-- 
James Blackwell          Try something fun: For the next 24 hours, give
Smile more!              each person you meet a compliment!

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