From: Joe Van Dyk <joevandyk@...>
Date: 2005-08-26T10:46:03+09:00
Subject: reading in C structs

I have the following C struct:

typedef struct
{
   short   Elev;         /* vertex elevation */
   u_char  Zone;         /* terrain fearture type */
   u_char  Mono;         /* monochrome brightness value */
   ulong   rgb;         /* rgb color components of vertex */

} cell_type

The rgb values are bitshifted into the rgb ulong, and then the rgb
ulong is converted to a network long.

Then a bunch of those structs are written into a file.  

What's the Ruby way of getting the RGB values out?  Is the unpack
specification "sccN"?  And then I'd unpack the network long with
"cccc"?