1package config
 2
 3import (
 4	"io"
 5	"io/fs"
 6	"os"
 7	"syscall"
 8)
 9
10func readRegular(path string, limit int, tooLarge string, check func(fs.FileMode) string) ([]byte, string) {
11	f, err := os.OpenFile(path, os.O_RDONLY|syscall.O_NONBLOCK, 0)
12	if err != nil {
13		return nil, reasonUnreadable
14	}
15	defer f.Close()
16	info, err := f.Stat()
17	if err != nil || !info.Mode().IsRegular() {
18		return nil, reasonUnreadable
19	}
20	if check != nil {
21		if reason := check(info.Mode()); reason != "" {
22			return nil, reason
23		}
24	}
25	if info.Size() > int64(limit) {
26		return nil, tooLarge
27	}
28	data, err := io.ReadAll(io.LimitReader(f, int64(limit)+1))
29	if err != nil {
30		return nil, reasonUnreadable
31	}
32	if len(data) > limit {
33		return nil, tooLarge
34	}
35	return data, ""
36}