[sldev] Variable blocks in UDP-Messages - documentation problem on the Wiki.

[Argent Stonecutter]

> "The message template details how many blocks are in the packet, which
> can be a fixed number or a variable number specified in the packet.
> Fixed is straightforward: there are 1, 2, 4, or more of those  
> blocks in
> order with no separators. Variable blocks are prepended with either  
> one
> or two bytes saying how many there are. If a block is Variable 2 in  
> the
> protocol map it uses two bytes in big endian format, so a count of 7
> would be specified with 0x0700. The same approach is used for the  
> fields."

This is misleading. I understand what they're trying to say, but what  
they're describing is little-endian format: the low byte comes first  
in little-endian, the high byte comes first in big-endian.

That is, two bytes containing a count of "7" in big-endian format is  
"0x00 0x07", in little-endian format it's "0x07 0x00".

If you are on a little-endian machine (intel), if you look at "0x00  
0x07" as a word, you will see "0x0700"... but that's because you've  
swapped the bytes. On a big-endian machine (power PC) you'll see  
"0x0007". The value "0x0007" is stored in big-endian format as "0x00  
0x07", in little endian as "0x07 0x00", but it's never "0x0700".

I suspect the best way to correct this on the Wiki would be to refer  
to the bytes as bytes, with a separator between them: "00 07" or  
"0x00 0x07", or to refer to it as "network order" and not provide an  
explicit example but rather include code using "ntohs()" showing how  
to read it.