basic_rng.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main(){
    // use current time to seed the prng used by rand()
    // if srand is not called (default: srand(1)), rand() will always generate the same sequence
    srand(time(0));
    for(int i=0; i<3; i++)
      printf("%d\n", rand());
    return 0;
}