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Re: Strangeness when moving data through an array.
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Re: Strangeness when moving data through an array.


  • Subject: Re: Strangeness when moving data through an array.
  • From: Andrew Farmer <email@hidden>
  • Date: Tue, 30 Nov 2004 23:36:05 -0800

On 30 Nov 2004, at 23:23, Sherm Pendley wrote:
On Nov 30, 2004, at 11:55 PM, John Draper wrote:
Now, I take the data from "pkt" and I want to later stick it into a
16 bit (u_short),  and would expect...   short_test=258,  but
after I execute this statement...

   bcopy((u_short)&pkt[MSEQ], &short_test, 2);
short_test = 160

WHY? What's going on? How can I extract data from an array in any arbitrary
index into it (even or odd), and still get back that 2 byte int correctly?

You're typecasting a pointer (&pkt[MSEQ]) to an integer (u_short), which smells fishy.


I'd say you probably need to cast to a different pointer type:

bcopy((u_short *)&pkt[MSEQ], &short_test, 2);

Or do something rather simpler.

pkt[MSEQ] = short_test;

(or is there a reason you aren't doing it this way?)

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References: 
 >Strangeness when moving data through an array. (From: John Draper <email@hidden>)
 >Re: Strangeness when moving data through an array. (From: Sherm Pendley <email@hidden>)

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