代码

#include<stdio.h>

#include<signal.h>

#include<unistd.h>

#include<sys/types.h>

#include<sys/wait.h>

int wait_mark;

void waiting(),stop();

void main()

{int  p1, p2;

signal(SIGINT,stop);

while((p1=fork())==-1);

if(p1>0)                            /*在父进程中*/

{①

while((p2=fork())==-1);

         If(p2>0)                   /*在父进程中*/

           { ②

               wait_mark=1;

               waiting(0);

               kill(p1,10);

               kill(p2,12);

               wait( );

               wait( );

               printf("parent process is killed!\n");

               exit(0);

            }

       else                        /*在子进程2中*/

           {

wait_mark=1;

signal(12,stop);

waiting();

lockf(1,1,0);

printf("child process 2 is killed by parent!\n");

lockf(1,0,0);

exit(0);

}

}

else                        /*在子进程1中*/

{

     wait_mark=1;

     signal(10,stop);

     waiting();

     lockf(1,1,0);

     printf("child process 1 is killed by parent!\n");

     lockf(1,0,0);

     exit(0);

}

}

void waiting()

{

   while(wait_mark!=0);

}

void stop()

{

   wait_mark=0;

}