[jsdl-wg] Re: [ogsa-hpcp-wg] Minutes for OGSA HPC Profile telecon (Aug 18 2006)

[Karl Czajkowski]

On Sep 01, Andreas Savva modulated:

>... The question I have if you change the argument type to a
> string is then why do you need multiple argument elements?
> 

The arguments to a POSIX command are a vector of strings.  The strings
may have any character in them, be empty strings, etc.  You cannot
trivially talk about encoding this vector in a string unless you
assume a bunch of "quoting" conventions.

Don't mix up a shell programming language with the underlying command
execution enviroment.  The shell parses the string command-line into
an array of strings according to its shell language rules, but the
underlying commands receive a vector.

The JSDL implementation should map this vector into whatever form it
requires, e.g. a properly escaped Bourne shell command if it is
cooking up some "run script" for a scheduler.  Things go horribly
wrong if you start assuming a particular back-end parser or not
escaping/quoting everything correctly.  You must avoid having users
work around implementation bugs by embedding implementation+platform
specific quoting syntax inside their argument data!

That said, Donal's point about string encoding is important to
remember. To do it right, the implementation needs to translate the
XML info set string (unicode I think, right?) to the locale in which
the program will run.  This might not be possible, unless we can
assume that the implementation can select an appropriately locale for
the characters being used.


karl

-- 
Karl Czajkowski
karlcz at univa.com