C language multi threaded programming using examples

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#define THREAD_NUM 10
void *test(void *args) {
 printf("tid %d: i say 'Hello'.n", args);
 return NULL;
}
int main() {
 int i, err;
 pthread_t child[THREAD_NUM];
 for(i = 0; i < THREAD_NUM; i++) {
  printf("Creating thread %dn", i);
  err = pthread_create(&child[i], NULL, test, (void *) i);
  if(err) {
   printf("Can't create thread %dn", i);
   exit(0);
  }
 }
 for(i = 0; i < THREAD_NUM; i++)
 pthread_join(child[i], NULL);
 printf("Thread initializen");
 return 0;
}