根据实现线程的函数（pthread_creat pthread_exit ptread_join）尝试编写一个线程编程

以下是一个简单的使用pthread_create、pthread_exit和pthread_join实现的线程编程的示例：

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

void *thread_func(void *arg) {
    int *num = (int *)arg;
    printf("Thread %d is running\n", *num);
    pthread_exit(NULL);
}

int main() {
    pthread_t threads[5];
    int thread_args[5];
    int i, result;

    for (i = 0; i < 5; i++) {
        thread_args[i] = i;
        result = pthread_create(&threads[i], NULL, thread_func, &thread_args[i]);
        if (result != 0) {
            perror("Thread creation failed");
            exit(EXIT_FAILURE);
        }
    }

    printf("All threads are created\n");

    for (i = 0; i < 5; i++) {
        result = pthread_join(threads[i], NULL);
        if (result != 0) {
            perror("Thread join failed");
            exit(EXIT_FAILURE);
        }
        printf("Thread %d is joined\n", i);
    }

    printf("All threads are joined\n");

    return 0;
}

该示例创建了5个线程，每个线程都会打印自己的编号，然后退出。主线程会等待所有子线程都退出后再退出。