Bug #605 -- Conditional execution

Kevin P. Fleming kpfleming at linuxfromscratch.org
Sun Feb 1 21:04:10 PST 2004

James Robertson wrote:

> The v3.1 DTD does not even have <if>, <then>, <else> in it anywhere. 
> hence the reason I removed them from the syntax doc.  Kinda difficult to 
> document something that does not exist.  So, I think the info in the doc 
> was out of place and those elements do not exist anywhere yet.  I am 
> thinking you are going to need them in v3.2 and up.

You're right, I had forgotten that I removed that stuff from the 3.1 
DTD. I found what I needed in a snapshot of the syntax doc though.

> I like this scenario.  Looks clean and easy to follow.  What would all 
> of the condition ATTLIST's be?  Same as what bash offers now?

I don't plan on <test> parsing its argument at all, except to check for:

- numeric string (zero means false, non-zero means yes)
- true/yes, or caseful variations thereof
- false/no, or caseful variations thereof

Anything else provided to <test> would be passed to the test program (or 
shell builtin, depending on your shell) and the result used as the 
result of the <test> element.

If we do decide to move any test verbs into nALFS, they would become new 
elements; for example, if we wanted to optimize -f (file existence), 
then we would add a <file-exists> condition element.

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