1// Copyright 2017 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// +build go1.7
6
7package unix_test
8
9import (
10	"fmt"
11	"testing"
12
13	"golang.org/x/sys/unix"
14)
15
16func TestDevices(t *testing.T) {
17	testCases := []struct {
18		path  string
19		major uint32
20		minor uint32
21	}{
22		// well known major/minor numbers according to
23		// https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/admin-guide/devices.txt
24		{"/dev/null", 1, 3},
25		{"/dev/zero", 1, 5},
26		{"/dev/random", 1, 8},
27		{"/dev/full", 1, 7},
28		{"/dev/urandom", 1, 9},
29		{"/dev/tty", 5, 0},
30	}
31	for _, tc := range testCases {
32		t.Run(fmt.Sprintf("%s %v:%v", tc.path, tc.major, tc.minor), func(t *testing.T) {
33			var stat unix.Stat_t
34			err := unix.Stat(tc.path, &stat)
35			if err != nil {
36				if err == unix.EACCES {
37					t.Skip("no permission to stat device, skipping test")
38				}
39				t.Errorf("failed to stat device: %v", err)
40				return
41			}
42
43			dev := uint64(stat.Rdev)
44			if unix.Major(dev) != tc.major {
45				t.Errorf("for %s Major(%#x) == %d, want %d", tc.path, dev, unix.Major(dev), tc.major)
46			}
47			if unix.Minor(dev) != tc.minor {
48				t.Errorf("for %s Minor(%#x) == %d, want %d", tc.path, dev, unix.Minor(dev), tc.minor)
49			}
50			if unix.Mkdev(tc.major, tc.minor) != dev {
51				t.Errorf("for %s Mkdev(%d, %d) == %#x, want %#x", tc.path, tc.major, tc.minor, unix.Mkdev(tc.major, tc.minor), dev)
52			}
53		})
54
55	}
56}
57