1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
|
#include <stdio.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <stdbool.h>
volatile bool finish = false;
volatile bool step = false;
pid_t pid;
void sig_handler(int signo)
{
if (pid)
if (step)
printf("Signaled: parent_step\n");
else
printf("Signaled: parent_command\n");
else
if (step)
printf("Signaled: child_step\n");
else
printf("Signaled: child_command\n");
finish = true;
}
int main(int argc, char *argv[])
{
int i=0;
if (argc>1)
step = true;
signal(SIGUSR1, sig_handler);
pid = fork();
if (pid)
if (step)
printf("Started: parent_step\n");
else
printf("Started: parent_command\n");
else
if (step)
printf("Started: child_step\n");
else
printf("Started: child_command\n");
while (!finish && i<10) {
fflush(stdout);
sleep(1);
i++;
}
if (pid)
wait(NULL);
return 0;
}
|
