ruanzhongduan.txt

关于操作系统实验的文件~~~很实用的~~~财操作系统

#include <stdio.h> 

#include <signal.h>  

 #include <unistd.h>  

#include <sys/types.h>  

int wait_flag; void stop( ); 

main( ) 

{  

         int pid1, pid2;   signal(3, stop);

         while ((pid1 = fork( )) == -1); 

         if ( (pid1 = fork() ) > 0)  

         {  

                  while ((pid2 = fork( )) == -1); 

                 if (( pid2 = fork()) > 0 )  

                  {      

                            wait_flag = 1;  signal(SIGINT, stop);   

                             sleep(5);  

                             kill(pid1, 16);  

                             kill(pid2,17);          

                             wait(0);    

                             wait(0);  

                             printf("\n Parent process is killed.\n"); 

                            exit(0);    

                   }       

                  else     

                   {    

                              wait_flag = 1;   

                              signal(17, stop);    

                               printf("\n Child process 2 is killed by parent.\n");       

                               exit(0);     

                       }   

            }        

           else

            {           

                       wait_flag = 1;                                                

                      signal(16, stop);   

                      printf("\n Child process 1 is killed by parent.\n");   

                      exit(0);    

                }        

}  

void stop( )

 {     

           wait_flag = 0;  

  }