Re: [C400-L] RE: Passing parameter back to calling CL

[Simon Coulter <shc@xxxxxxxxxxxxxxxxx>]

On 02/10/2004, at 5:05 AM, David C. Shea wrote:

> When I look at the dump, I see:
>
> &RRN9              *DEC               15 0        '        '
> 1E0000000000000F
>
> What should the format of the passed variable from the CL be?

CL is expecting a packed decimal value so you better make damned sure 
that's what you return from C.

> In the C program:
> .
> .
> int main(int argc, char * argv[])
> .
> .
> *argv[2] = riofb_fwd->rrn;
> .
> .
> I'm guessing that I need to convert a field format someplace...

Your problem is that C has no idea what *argv[2] is. It is just a 
pointer to some chunk of storage. The only thing C knows at this point 
is that riofb_fwd->rrn is an unsigned long integer so it assigns the 
integer value to the bytes addressed by the pointer. But because C 
rather stupidly treats char as a numeric type and *argv[2] is a char it 
copies (via assignment) only the last byte of the unsigned long. The 
value in riofb_fwd->rrn was probably 30 which is x'0000001E' (or 0x1e 
since this is the C list). You can see from the dump that the 1E has 
been assigned to the first byte of the packed decimal. x'E' is not a 
valid value in a packed decimal (digits 0 to 9 only) thus the decimal 
data error.

You need to ensure C understands the receiving data type so it can 
convert correctly. The following code

decimal(15,0) * rrn = (decimal(15,0)*)argv[2];
*rrn = riofb_fwd->rrn;

will do it. If you don't do it this way you'll have to do something 
ugly like passing character values or convert to decimal in the C (by 
assigning to an appropriate decimal variable) and copy the correct 
number of bytes into your caller's storage. Doesn't C suck?

Regards,
Simon Coulter.
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