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Date: Fri, 22 Aug 2008 12:03:24 +0300
From: Niklas Holsti <niklas.holsti@tidorum.invalid>
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Subject: Re: C chars_ptr STORAGE_ERROR in Imported function
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Date: 2008-08-22T12:03:24+03:00
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Kim Rostgaard Christensen wrote:
> Hello there
> 
> I am in progress of binding the pcap c library to ada, it is a part of a
> school project. And for that i need a funtion that modifies a parameter 
> to a function like so:
> 
> char    *pcap_lookupdev(char *);
> 
...
> 
> Do I need to declare the buffer and then then pass its c pointer to the 
> function?

That is certainly my interpretation of the "man" text:

    char *pcap_lookupdev(char *errbuf)

    pcap_lookupdev() returns a pointer to a network device
    suitable for use with pcap_open_live() and pcap_lookupnet().
    If there is an error, NULL is returned and errbuf is filled
    in with an appropriate error message.

There is no hint that pcap_lookupdev() itself allocates the errbuf; 
it just puts something in the caller-provided errbuf. And no doubt 
places a NUL terminator after the message.

HTH

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
       .      @       .