wait()函数,作用：阻塞等待任意子进程，回收子进程8kb物理内存

#include<stdio.h>
#include<stdlib.h>
#include <unistd.h>
//wait()函数
//作用：阻塞等待任意子进程，回收子进程8kb物理内存
int main(void)
{
printf("main process pid = %d\n",getpid());

pid_t pid;
pid = fork();//创建子进程
if(pid < 0)
{
perror("fork error");
exit(1);//结束进程
}

if(pid == 0)
{
printf("子进程pid = %d\n",getpid());
sleep(1);
printf("********\n");
exit(1);
}

if(pid > 0)
{
printf("父进程pid = %d\n",getpid());
//阻塞等待任意子进程，回收子进程8kb物理内存
wait(NULL);
printf("-------------\n");
exit(1);
}

return 0;
}
/*
$ ./a.out
main process pid = 25446
父进程pid = 25446
子进程pid = 25447
********
-------------
*/