├── README.markdown
└── main.go


/README.markdown:
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 1 | # init
 2 | 
 3 | Minimal init(8) for use with Docker. Wraps your command
 4 | to reap zombie processes.
 5 | 
 6 | Heavily influenced by [Xe/init](https://github.com/Xe/init)
 7 | 
 8 | ## Installation
 9 | 
10 |     $ go get github.com/ddollar/init
11 | 
12 | ## Usage
13 | 
14 |     $ init /path/to/subcommand args
15 | 
16 | ## License
17 | 
18 | Apache 2.0 © 2015 David Dollar
19 | 


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/main.go:
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 1 | package main
 2 | 
 3 | import (
 4 | 	"flag"
 5 | 	"fmt"
 6 | 	"log"
 7 | 	"os"
 8 | 	"os/exec"
 9 | 	"os/signal"
10 | 	"syscall"
11 | 	"time"
12 | )
13 | 
14 | var useUsr1 *bool
15 | 
16 | func reap() {
17 | 	syscall.Wait4(-1, nil, syscall.WNOHANG, &syscall.Rusage{})
18 | }
19 | 
20 | func terminate() {
21 | 	if *useUsr1 {
22 | 		syscall.Kill(-1, syscall.SIGUSR1)
23 | 		time.Sleep(2 * time.Second)
24 | 	}
25 | 
26 | 	syscall.Kill(-1, syscall.SIGTERM)
27 | 	time.Sleep(5 * time.Second)
28 | 
29 | 	syscall.Kill(-1, syscall.SIGKILL)
30 | 	os.Exit(0)
31 | }
32 | 
33 | func handleSignal(sig os.Signal, handler func()) {
34 | 	ch := make(chan os.Signal, 1)
35 | 	signal.Notify(ch, sig)
36 | 
37 | 	for _ = range ch {
38 | 		handler()
39 | 	}
40 | }
41 | 
42 | func main() {
43 | 	go handleSignal(syscall.SIGCHLD, reap)
44 | 	go handleSignal(syscall.SIGTERM, terminate)
45 | 	go handleSignal(syscall.SIGKILL, terminate)
46 | 
47 | 	useUsr1 = flag.Bool("usr1", false, "send usr1 before term")
48 | 
49 | 	flag.Parse()
50 | 
51 | 	args := flag.Args()
52 | 
53 | 	if len(args) < 1 {
54 | 		fmt.Println("usage: init <command>")
55 | 		os.Exit(1)
56 | 	}
57 | 
58 | 	cmd := exec.Command(args[0], args[1:]...)
59 | 	cmd.Stdin = os.Stdin
60 | 	cmd.Stdout = os.Stdout
61 | 	cmd.Stderr = os.Stderr
62 | 	err := cmd.Run()
63 | 
64 | 	if err != nil {
65 | 		log.Fatal(err)
66 | 	}
67 | }
68 | 


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