1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <string.h>
4 #include <unistd.h>
5 #include <signal.h>
6 #include <assert.h>
7
8 void printSignal()
9 {
10 sigset_t set;
11 int ret = 0;
12 sigemptyset(&set);
13 ret = sigpending(&set);
14 int i = 1;
15 for (i = 1; i < 65; i++)
16 {
17 if (0 == (ret = sigismember(&set, i)))
18 {
19 printf("0");
20 }
21 else if (1 == ret)
22 {
23 printf("1");
24 }
25 }
26 puts("");
27 }
28
29 void my_sigaction (int num, siginfo_t *st, void *dat)
30 {
31 int ret = 0;
32 if (SIGINT == num)
33 {
34 sigset_t set;
35 sigemptyset(&set);
36 ret = sigaddset(&set, SIGQUIT);
37 assert(-1 != ret);
38 ret = sigprocmask(SIG_UNBLOCK, &set, NULL);
39 assert(-1 != ret);
40 printf("my_sigaction\n");
41 printSignal();
42 printf("func myhandler num = %d\n", num);
43 }
44 else
45 {
46 printf("signal is no SIGQUIT\n");
47 }
48 }
49
50
51
52 int main(void)
53 {
54 int ret = 0;
55
56 /* 阻塞信号 */
57 sigset_t set;
58 sigemptyset(&set);
59 ret = sigaddset(&set, SIGQUIT);
60 assert(-1 != ret);
61 ret = sigprocmask(SIG_BLOCK, &set, NULL);
62 assert(-1 != ret);
63 printf("阻塞信号\n");
64 //printSignal();
65 sigemptyset(&set);
66 /*
67 sigpending 是从未决状态字中读取的， 但是未决信号并不能立即得到block的同步
68 也就是说在block置1时pending并不能够立即的更新为1
69 */
70 //sigpending(&set);
71
72 /* 注册信号 */
73 struct sigaction act;
74 act.sa_sigaction = my_sigaction;
75 ret = sigemptyset(&(act.sa_mask));
76 assert(-1 != ret);
77 ret = sigaction(SIGINT, &act, NULL);
78 assert(-1 != ret);
79 printf("注册信号\n");
80 printSignal();
81
82 while (1)
83 {
84 printSignal();
85 sleep(1);
86 }
87 return 0;
88 }
