David --- Senior Programmer Analyst --- Wgo Wagner wrote:
> I have a number of files which I have transferred from another
> system. I am trying to read the data, but running into a problem when
> I hit what is a negative number (Each field is 4 characters in
> length).
>
> Here is the unpack:
>
> @MyWorka =
> unpack("a8Nsa6a10ssa52H8a4H8H8a136",$fb010dbuf);
>
> This is the closest I have been able to get the info. If the value is
> positive, number is okay, but if negative, then just a huge number.
> If you look at rcd#3 Bill, you will see what I mean. If i I enter
> that value and use printf and hex ( another script ), I get the
> negative number I expect.
>
> What am I missing?
Hi David. I assume you mean the 'N' field? This is an unsigned 32-bit
big-endian value, so it will always be positive. You can try 'l'
(small el) which is a signed 32-bit value, but depending on your
platform architecture it may not process the bytes in the right order.
If not, you can just twos-complement your positive number
depending on the sign bit:
sub correct_sign {
($_[0] ^= 0xFFFFFFFF) += 1 if $_[0] & 0x80000000;
}
Note that this modifies its parameter 'in place' and so must be
called with a scalar variable as its parameter.
Cheers,
Rob
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
