RE: An unfulfilled requirement maybe?

On second thought, environmental variables could also have multiple values,
separated by a platform defined character (on Windows, that's ";". I don't
know about others). Having said that, such a function would need a way to
select a special path from the listed, or "any of the listed" or "the whole
value" in case the value is not even a path.

How should this be done... probably have a second argument indicating what
value to use. The default value of "0" to this optional argument should mean
the complete value. A special value, like say "-1" should mean "any one".
And all positive integers should mean a specific value in the path order.
Nah... this means you won't be able to select paths from the end, which may
be desirable in some cases. Then maybe any non-numeric value (i.e. "NaN")
should mean "any of the available" while a negative integer would mean "that
path from the end"?

-----Original Message-----
From: Vasil Rangelov [mailto:boen.robot@gmail.com] 
Sent: Tuesday, November 27, 2007 9:41 PM
To: 'public-xml-processing-model-comments@w3.org'
Subject: RE: An unfulfilled requirement maybe?

Oh. That. Well, again, if a sysntax for environmental variables is
established, an explicit reference to the PATH may be added in the command
path and/or CWD. Suppose AVTs were the type of syntax, then the final path
may be something like:
<p:exec ... command="{PATH}perl" ... />


Another way, now that I think about it, could possibly involve a new
extension function (suppose called something like p:env($varname as string))
that can be embedded in one of the options like:

<p:exec>
<p:option name="command" select="concat(p:env('PATH'),'perl')"/>
</p:exec>

In this case, CWD is of no importance, since PATH is always an absolute path
(or at least is by default anyway).
-----Original Message-----
From: Henry S. Thompson [mailto:ht@inf.ed.ac.uk] 
Sent: Tuesday, November 27, 2007 9:21 PM
To: Vasil Rangelov
Cc: public-xml-processing-model-comments@w3.org
Subject: Re: An unfulfilled requirement maybe?

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Vasil Rangelov writes:

> "search path"? What is that? That's the first time I hear about it, and I
> found no info on Wikipedia about it.

The PATH environment variable.  On your proposal, how can I write a
pipeline which e.g. runs perl w/o knowing the full path to its
location?

As things stand, I just say <p:exec . . . command="perl". . ./>, but
that won't work under your proposal.

ht
- -- 
 Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
                     Half-time member of W3C Team
    2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
            Fax: (44) 131 650-4587, e-mail: ht@inf.ed.ac.uk
                   URL: http://www.ltg.ed.ac.uk/~ht/
[mail really from me _always_ has this .sig -- mail without it is forged
spam]
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Received on Tuesday, 27 November 2007 20:02:29 UTC