相关博客
Linux下的信号（一）
http://blog.csdn.NET/double_happiness/article/details/72848372
Linux下的信号（二）
http://blog.csdn.Net/double_happiness/article/details/72897148
僵尸进程
http://blog.csdn.net/double_happiness/article/details/70168897
在上面关于僵尸进程的父进程等待时，父进程有两种等待方式，即阻塞和非阻塞，下面我们来验证一下，子进程退出时的其他情况
验证子进程退出时会给父进程发送信号
#include<stdio.h> #include<signal.h> #include<stdlib.h> #include<sys/types.h> void handler(int sig){ printf("sig is %d,pid is %d\n",sig,getpid()); } int main() { signal(SIGCHLD,handler); int id=fork(); if(id<0){ perror("fork"); exit(-1); } else if(id==0){ sleep(3); printf("i am child, my pid is %d\n",getpid()); exit(2); } else{ while(1){ printf("i am parent,my pid is %d\n",getpid()); sleep(1); } } return 0; }
运行结果：
父进程等待子进程的异步版本代码实现：
#include<stdio.h> #include<signal.h> #include<stdlib.h> #include<sys/types.h> void handler(int sig){ printf("sig is %d,pid is %d\n",sig,getpid()); } int main() { int id=fork(); if(id<0){ perror("fork"); exit(-1); } else if(id==0){ sleep(3); printf("i am child, my pid is %d\n",getpid()); exit(2); } else{ struct sigaction act; act.sa_handler = handler; sigemptyset(&act.sa_mask); act.sa_flags = 0; sigaction(SIGCHLD, &act, NULL); while(1){ printf("i am parent,my pid is %d\n",getpid()); sleep(1); } } return 0; }
运行结果：
