#include <stdio.h>

#ifdef SILUMINE
void tervita(void){
  printf("Alles testitakse\n");
}
#else
void tervita(void){
  printf("Tervist, kasutaja\n");
}
#endif

int main(void){
  tervita();
  return 0;
}

/*
[jaagup@minitorn c]$ gcc def4a.c
[jaagup@minitorn c]$ ./a.out
Tervist, kasutaja
[jaagup@minitorn c]$ gcc -DSILUMINE def4a.c
[jaagup@minitorn c]$ ./a.out
Alles testitakse
*/