程序代码：

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

void *print_message_function( void *ptr );

int main()
{
     pthread_t thread1, thread2;
     char *message1 = "Thread 1";
     char *message2 = "Thread 2";
     int  iret1, iret2;

    /* Create independent threads each of which will execute function */

     iret1 = pthread_create( &thread1, NULL, print_message_function, (void*) message1);
     iret2 = pthread_create( &thread2, NULL, print_message_function, (void*) message2);

     /* Wait till threads are complete before main continues. Unless we  */
     /* wait we run the risk of executing an exit which will terminate   */
     /* the process and all threads before the threads have completed.   */

     pthread_join( thread1, NULL);    /* wait for thread termination: int pthread_join(pthread_t thread, void **value_ptr);*/
     pthread_join( thread2, NULL);     /*NULL 表示对线程的返回值不感兴趣*/

     printf("Thread 1 returns: %d\n",iret1);
     printf("Thread 2 returns: %d\n",iret2);
     exit(0);
}

void *print_message_function( void *ptr )
{
     char *message;
     message = (char *) ptr;
     printf("%s \n", message);
}

程序代码：

#include "utilites.h"

pthread_t ntid;

void 
printtids(const char *s) {
    pid_t pid;
    pthread_t tid;
    pid = getpid();
    tid = pthread_self();
    printf("%s pid %u tid %u (0x%x)\n",s,(unsigned int)pid,(unsigned int)tid, (unsigned int)tid);
}

void *
thr_fn(void *arg) {
    printtids("new thread: ");
    return((void*)0);
}

int 
main(void) {
    int err;
    err = pthread_create(&ntid, NULL, thr_fn,NULL);
    if(err != 0)
        err_quit("can't create thread: %s\n",strerror(err));
    printtids("main thread: ");
//    sleep(1);                
    exit(0);
}