create threads and wait using join

create_threads.c

#include "stdio.h"
#include "assert.h"
#include "pthread.h"

void *myThread(void *arg) {
  printf("%s\n", (char *) arg);
  return NULL;
}

int main() {
  pthread_t p1, p2;
  int rc;
  
  rc = pthread_create(&p1, NULL, myThread, "A"); assert(rc == 0);
  rc = pthread_create(&p2, NULL, myThread, "B"); assert(rc == 0);
  
  rc = pthread_join(p1, NULL); assert(rc == 0);
  rc = pthread_join(p2, NULL); assert(rc == 0);
  
  printf("main: end\n");
  return 0;
}

compile it with

gcc -Wall -pthread create_threads.c -o create_threads
./create_threads