yep exactly that. I had that exact issue. Junk coming in from a tcp/ppp connection then had to unpack it. Tons of garbage moves and byte offsetting and then making sure you keep the endianness correct too. On the platform I was using luckily memcpy could do most of what I needed. Not the best way to do it but the wildly out of date branch of gcc could do it. Got pretty good at picking junk out of random streams shifting and and/or whatever was needed. Totally useless skill for what I work on these days.