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Date: Tue, 21 Feb 2006 17:16:11 +0100
From: Poul-Erik Andreasen <poulerik@pea.dk>
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Subject: Re: binding to C: popen
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Date: 2006-02-21T17:16:11+01:00
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Georg Bauhaus wrote:
> Poul-Erik Andreasen wrote:
> 
> 
>>Yes but a C pointer is in Ada represented as system.address and i can
>>not test that for O the the systems.address_image gives 0804C060 and if
>>that is a stadart c value for a null-pointer things are fine, but that
>>seems to be a hack.
> 
> 
> System.Null_Address, or Interfaces.C.Strings.Null_Ptr perhaps?
> 
> You could consider writing a predicate like
> 
>   fucntion is_null(p: System.Address) return Boolean;
> 
> in order to have the comparison in one place only.
> 
> HTH,
>  Georg 
In the meantime i have found out that i will not help much. The 
null-pointer return will only occur if there is a internal error, and 
since  sh normaly will succed even if the command fails it somthing that
rarely occurs. I can not even find out a way to test it.

Poul-Erik