slot.go RawHistoryFolder

1package wayland
2
3import (
4	"bytes"
5	"os"
6	"strconv"
7
8	"github.com/bnema/neferwl/internal/ports"
9	"github.com/bnema/purego-libwayland/server"
10)
11
12// procEnv reads one environment variable of a running process.
13type procEnv interface {
14	Lookup(pid int, key string) (string, bool)
15}
16
17// linuxProcEnv reads /proc/<pid>/environ: the environment the process started
18// with. A slot command that forks its window process passes it down, since
19// children inherit the environment.
20type linuxProcEnv struct{}
21
22func (linuxProcEnv) Lookup(pid int, key string) (string, bool) {
23	if pid <= 0 {
24		return "", false
25	}
26	data, err := os.ReadFile("/proc/" + strconv.Itoa(pid) + "/environ")
27	if err != nil {
28		return "", false
29	}
30	prefix := []byte(key + "=")
31	for entry := range bytes.SplitSeq(data, []byte{0}) {
32		if v, ok := bytes.CutPrefix(entry, prefix); ok {
33			return string(v), true
34		}
35	}
36	return "", false
37}
38
39// slotToken returns the SlotEnv value of the client process, if any. It
40// reads /proc only while core waits for a slot window. There is no per-client
41// cache: libwayland may reuse a client address after a disconnect.
42func (s *Server) slotToken(c server.Client) string {
43	if !s.slotsPending {
44		return ""
45	}
46	v, _ := s.env.Lookup(c.PID(), ports.SlotEnv)
47	return v
48}