1package interrupt
 2
 3import (
 4	"fmt"
 5	"os"
 6	"os/signal"
 7	"syscall"
 8)
 9
10// Cleaner type referes to a function with no inputs that returns an error
11type Cleaner func() error
12
13var cleaners []Cleaner
14var active = false
15
16// RegisterCleaner is responsible for regisreting a cleaner function. When a function is registered, the Signal watcher is started in a goroutine.
17func RegisterCleaner(f ...Cleaner) {
18	for _, fn := range f {
19		cleaners = append([]Cleaner{fn}, cleaners...)
20		if !active {
21			active = true
22			go func() {
23				ch := make(chan os.Signal, 1)
24				signal.Notify(ch, syscall.SIGINT, syscall.SIGTERM, os.Interrupt)
25				<-ch
26				// Prevent un-terminated ^C character in terminal
27				fmt.Println()
28				fmt.Println("Cleaning")
29				errl := Clean()
30				for _, err := range errl {
31					fmt.Println(err)
32				}
33				os.Exit(1)
34			}()
35		}
36	}
37}
38
39// Clean invokes all registered cleanup functions, and returns a list of errors, if they exist.
40func Clean() (errorlist []error) {
41	for _, f := range cleaners {
42		err := f()
43		if err != nil {
44			errorlist = append(errorlist, err)
45		}
46	}
47	cleaners = []Cleaner{}
48	return
49}