wait函数简单介绍

来源：互联网发布：淘宝论坛编辑：程序博客网时间：2024/06/05 05:49

#include <stdio.h>#include <stdlib.h>#include <sys/types.h>#include <unistd.h>#include <sys/wait.h>int main(){    pid_t pid;    char *msg;    int k;    int exit_code;    printf("Study how to get exit code!\n");    pid = fork();    switch(pid)    {    case 0:        msg = "Child process is running!\n";        k = 5;        exit_code = 37;        break;    case -1:        perror("Process Creation Failed!\n");        exit(1);    default:        exit_code = 0;        break;    }//父进程都会执行以下这段代码//子进程的pid为0，父进程的pid为子进程的ID    if(pid != 0)    {        int stat_val;        pid_t child_pid;        child_pid = wait(&stat_val);        printf("Child process has exited,pid = %d\n",child_pid);        if(WIFEXITED(stat_val))            printf("Child exited with code %d\n",WEXITSTATUS(stat_val));        else            printf("Child exited abnormally!\n");    }    else    {        while(k-- > 0)        {            puts(msg);            sleep(2);        }    }    exit(exit_code);}

执行结果：

[root@localhost code]# ./wait Study how to get exit code!Child process is running!Child process is running!Child process is running!Child process is running!Child process is running!Child process has exited,pid = 2975

父进程遇到wait函数先会挂起，知道子进程执行完成后在执行！

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