I think the slattach documentation is fairly vague and misleading.
Here are just a few minor suggestions:
1) Mention that it forks off a background process
2) Say that it basically sets a few flags (& enumerate?) on the line and
holds it open; as far as I know, it doesn't define the network source and
destination addresses.  In fact, if I had known how little it did, I wouldn't
even have bothered using it from my slipmaint/slipup script.
3) Possibly add a no-daemon flag (don't run in bckgrnd) - it's hard to 
figure out what PID the background proc is without race conditions.
4) Get rid of the:
        register char *dev = argv[1];
   since it is overwritten later by:
        dev = *argv;
5) Use [f]pathconf to determine buffersize for the device filename, not a
statically allocated buffer of magic size (32b, in this case).
-- 
VaX#n8 (vak-sa-nate) - n, CS senior++ and Unix junkie - vax@ccwf.cc.utexas.edu
Just the vax-man.  Read my MIPS, no new VAXes!        - PGP key on request