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
|
package main
import (
"fmt"
"os"
"os/exec"
"strconv"
"time"
)
func traceme1() {
fmt.Printf("parent starting\n")
}
func traceme2(n string) {
fmt.Printf("hello from %s\n", n)
}
func traceme3() {
fmt.Printf("done\n")
}
func main() {
exe, _ := os.Executable()
switch os.Args[1] {
case "spawn":
traceme1()
n, _ := strconv.Atoi(os.Args[2])
cmds := []*exec.Cmd{}
for i := 0; i < n; i++ {
cmd := exec.Command(exe, "child", fmt.Sprintf("C%d", i))
cmd.Stdout = os.Stdout
cmd.Start()
cmds = append(cmds, cmd)
}
for _, cmd := range cmds {
cmd.Wait()
}
time.Sleep(1 * time.Second)
traceme3()
case "child":
traceme2(os.Args[2])
case "spawn2":
cmd := exec.Command(os.Args[2])
cmd.Stdout = os.Stdout
cmd.Start()
cmd.Wait()
}
}
|
