这个可以程序主要测试高级并发服务器程序怎样写会避免僵尸进程？

#include <unistd.h> #include <stdio.h> #include<stdlib.h> #include<signal.h>

int main(void) { //signal(SIGCHLD, SIG_IGN);

   int i=0; printf("i son/pa ppid pid fpid\n"); //ppid指当前进程的父进程pid //pid指当前进程的pid, //fpid指fork返回给当前进程的值 

   while(1){ sleep(1); //之所以加入这个时间是因为，容易看出程序的变化，不然根本看不出变化，连鼠标都懂不了！ pid_t fpid=fork(); if(fpid==0) {printf("%d child %4d %4d %4d\n",i,getppid(),getpid(),fpid); //return 0; //这两个效果一样的！

            exit(0); } } return 0; } [root@linux Desktop]# gcc b.c [root@linux Desktop]# ./a.out i son/pa ppid pid fpid 0 child  16980 16981    0

0 child  16980 16982    0

0 child  16980 16983    0

0 child  16980 16985    0

0 child  16980 16988    0

0 child  16980 16990    0

0 child  16980 16991    0

0 child  16980 16993    0

0 child  16980 16995    0

0 child  16980 16996    0

^C [root@linux Desktop]# [root@linux Desktop]# ps aux | grep -w 'Z' //产生了好多僵尸进程了 root 16981  0.0  0.0      0     0 pts/2    Z+   20:38   0:00 [a.out] <defunct>defunct某些系统中用它来作为僵尸的标志 root 16982  0.0  0.0      0     0 pts/2    Z+   20:38   0:00 [a.out] <defunct> root 16983  0.0  0.0      0     0 pts/2    Z+   20:38   0:00 [a.out] <defunct> root 16985  0.0  0.0      0     0 pts/2    Z+   20:38   0:00 [a.out] <defunct> root 16987  0.0  0.0   4340   804 pts/3    S+   20:38   0:00 grep -w Z [root@linux Desktop]# 当把signal(SIGCHLD, SIG_IGN);这行代码加上时输出结果如下： [root@linux Desktop]# gcc b.c [root@linux Desktop]# ./a.out i son/pa ppid pid fpid 0 child  17135 17136    0

0 child  17135 17137    0

0 child  17135 17139    0

0 child  17135 17140    0

0 child  17135 17141    0

0 child  17135 17142    0

0 child  17135 17145    0

0 child  17135 17147    0

0 child  17135 17150    0

0 child  17135 17151    0

0 child  17135 17152    0

^C [root@linux Desktop]# //没有僵尸进程产生 [root@linux Desktop]# ps aux | grep -w 'Z' root 17144  0.0  0.0   4336   796 pts/3    S+   20:42   0:00 grep -w Z [root@linux Desktop]# ps aux | grep -w 'Z' root 17149  0.0  0.0   4336   792 pts/3    S+   20:42   0:00 grep -w Z [root@linux Desktop]# 

 

<defunct>