Hi Bo! :-)

 BS> struct _pkthdr
 BS> {
 BS>   sword orig_node;        /* originating node */
 BS>   sword dest_node;        /* destination node */
 BS> }  __attribute__((packed, aligned(2)));
That's not packed, that's aligned on two byte boundaries - but that
shouldn't matter here.

 BS> The structure contains most words and a couple of bytes.
What is an sword supposed to be? I'd stick to standard names.

 BS> It's beeing readed by
 BS> read(fp, &pkthdr, sizeof(struct _pkthdr));
 BS> Should I read every single variable in the structure to get it 
 BS> working?
The main question is whether you know the endianness of the input or can
easily find it out?

Reading the full structure at once is okay. After that, you can convert all
the values that need to be byteswapped/converted.

Ciao
Pascal

--- Msged/LNX 6.1.1