-
Notifications
You must be signed in to change notification settings - Fork 0
/
multi_proc.c
83 lines (66 loc) · 1.32 KB
/
multi_proc.c
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
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
#include<stdio.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/wait.h>
int main(void)
{
pid_t child1, child2, child;
child1 = fork();
child2 = fork();
if (child1==-1)
{
printf("Child1 fork error \n");
exit(1);
}
else if (child1==0)
{
printf("In Child1: execute 'ls -l'\n");
if (execlp("ls","ls","-l",NULL)<0)
{
printf("Child1 execlp error\n");
}
}
if (child2==-1)
{
printf("Child2 fork error \n");
exit(1);
}
else if (child2==0)
{
printf("In Child2: sleep for 5 seconds and then exit\n");
sleep(5);
exit(0);
}
else // in father process wait the two child processes to end
{
printf(" in father process:\n");
child = waitpid(child1,NULL,0); // block waiting
if (child == child1)
{
printf("Get child 1 exit code\n");
}
else
{
printf("Error occured!\n");
}
do
{
child = waitpid(child2,NULL,WNOHANG); // unblock waiting
if (child==0)
{
printf("the child2 process has not exited\n");
sleep(1);
}
} while (child ==0);
if (child == child2)
{
printf("Get child2 exit code \n");
}
else
{
printf("Error occured!\n");
}
}
exit(0);
}