pthread.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>

void *print(void *arg) { 
    char *msg = arg;
    printf("msg : %s\n", msg);
    return NULL;
}

int main(int argc, char **argv) { 
    pthread_t id[2];
    int ret;

    /*
    int pthread_create(pthread_t *thread, const pthread_attr_t *attr,
                   void *(*start_routine) (void *), void *arg);
    */

    char msg1[] = "hello";
    char msg2[] = "world";

    ret = pthread_create(&id[0], NULL, print, msg1);
    if(ret != 0) {
        printf("pthread_create ERROR\n");
        return -1;
    } 

    ret = pthread_create(&id[1], NULL, print, msg2);
    if(ret != 0) {
        printf("pthread_create ERROR\n");
        return -1;
    } 
    
    ret = pthread_join(id[0], NULL);
    if(ret != 0) {
        printf("pthread_join ERROR\n");
        return -1;
    } 

    ret = pthread_join(id[1], NULL);
    if(ret != 0) {
        printf("pthread_join ERROR\n");
        return -1;
    } 
    
    return 0;
}