Linux实验十(3)---Linux系统信号机制实验

步骤1：同上

步骤2：建立目录

　　cd workdir/linux/application/10-comm/

　　mkdir signal

　　cd signal/

步骤3：复制

　　cp /mnt/hgfs/share/2.\ Linux系统部分/14.\ Linux系统信号机制实验/实验代码/signal.c ./ -a

步骤4：执行

　　gcc signal.c -o signal

　　./signal

　　系统调用signal()让父进程捕捉键盘上的中断信号（即按Ctrl + c），当捕捉到中断信号后父进程调用kill()向两个子进程发出信号，子进程捕捉到父进程发来的信号后，输出上述信息。

附：程序源码

 1 #include<stdio.h>
 2 #include<signal.h>
 3 #include<unistd.h>
 4 #include<stdlib.h>
 5 
 6 int wait_mark;
 7 void waiting(), stop();
 8 
 9 int main(int argc, char *argv[])
10 {  
11     int  p1, p2;
12     signal(SIGINT,stop);
13 
14     while((p1 = fork()) == -1);
15 
16     if (p1 > 0)                            /*在父进程中*/
17     {
18         while((p2 = fork()) == -1);
19 
20         if (p2 > 0)                    /*在父进程中*/
21         {
22             wait_mark = 1;
23             waiting();
24             kill(p1, 10);
25             kill(p2, 12);
26             wait(NULL);
27             wait(NULL);
28             printf("parent process exit!\n");
29             exit(0);
30         }
31         else                        /*在子进程2中*/
32         {
33             wait_mark = 1;
34             signal(12, stop);
35             waiting();
36             lockf(1, 1, 0);
37             printf("child process 2 is killed by parent!\n");
38             lockf(1, 0, 0);
39             exit(0);
40         }
41     } 
42     else                                /*在子进程1中*/
43     {
44         wait_mark = 1;
45         signal(10, stop);
46         waiting();
47         lockf(1, 1, 0);
48         printf("child process 1 is killed by parent!\n");
49         lockf(1, 0, 0);
50         exit(0);
51     }
52 }
53 
54 void waiting()
55 {
56     while(wait_mark != 0);
57 }
58 
59 void stop()
60 {
61     wait_mark = 0;
62 }