> Anyway, I've tried compiling Hello World on LSX, and I get "1: External
> definition syntax" error. Some help would be nice, but more generally, is
> anyone on this list more than vaguely familiar with LSX, or 6th Edition
> itself?
>
> void main () {
>         printf("Hello World!");
> }
>
> It seems that the 7th Edition was the beginning of the standard library in
> C, and that this is missing in LSX. I'm not sure if printf is an intrinsic
> function in (6th Edition) C, or if it's from a library.
>

First off, VOID MAIN is not legal in any standard version of C.  Even when
the language allows implementation defined extensions to the main
signature, it must still return int.

If you have a later version of language supported, you have to define
printf rather than allowing it default define as an int returning
function.

Add #include <stdio.h>

# cp /dev/tty8 addr.c
main() {
  int a;
  printf("main address: %u (0%o)\n", main, main);
  printf("stack address: %u (0%o)\n", &a, &a);
  printf("heap address: %u (0%o)\n", sbrk(0), sbrk(0));
}      
^D
# cc addr.c
# a.out
main address: 16410 (040032)
stack address: 40934 (0117746)
heap address: 17920 (043000)