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
84
85
86
87
88
89
90
91
92
93
94
|
// usage:
// go build -o waybar-gammastep gammastep.go
package main
import (
"encoding/json"
"log"
"os"
"os/exec"
"os/signal"
"strings"
. "syscall"
)
func main() {
var (
update = make(chan os.Signal, 1)
cancel = make(chan os.Signal, 1)
)
signal.Notify(update, SIGUSR1, SIGUSR2, SIGHUP)
signal.Notify(cancel, SIGTERM, SIGINT)
// could use golang.org/x/sys/unix.Prctl here
// but I want to avoid the dependency
if _, _, e := Syscall6(SYS_PRCTL,
uintptr(PR_SET_PDEATHSIG),
uintptr(SIGTERM),
0, 0, 0, 0); e != 0 {
log.Printf("error: %v", e)
os.Exit(1)
}
// if err := Prctl(PR_SET_PDEATHSIG,
// SIGTERM,
// 0, 0, 0); err != nil {
// fmt.Fprintln(os.Stderr, err)
// os.Exit(1)
// }
lookup()
for {
select {
case sig := <-update:
switch sig {
case SIGUSR1:
// redshift off
printJson("day", "day")
case SIGUSR2:
// redshift on
printJson("night", "night")
case SIGHUP:
lookup()
}
case <-cancel:
log.Printf("%v exiting\n", os.Args[0])
os.Exit(0)
}
}
}
func printJson(state, tooltip string) {
_ = json.NewEncoder(os.Stdout).Encode(map[string]interface{}{
"class": state,
"alt": state,
"tooltip": "gammastep: " + tooltip,
"text": state,
})
}
func lookup() {
b, err := exec.Command("gammastep", "-p").CombinedOutput()
if err != nil {
log.Printf("error: %v", err)
return
}
var period string
var fds = strings.Fields(string(b))
for idx, f := range fds {
if f == "Period:" {
period = fds[idx+1]
break
}
}
switch period {
case "Night":
printJson("night", "night")
case "Transition":
printJson("night", "transition")
case "Daytime":
printJson("day", "day")
default:
printJson("unknown", "unknown")
}
}
|
