1// Copyright 2019 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//go:build darwin || freebsd || netbsd || openbsd
6
7package syscall_test
8
9import (
10	"fmt"
11	"os"
12	"path/filepath"
13	"slices"
14	"strings"
15	"syscall"
16	"testing"
17	"unsafe"
18)
19
20func TestGetdirentries(t *testing.T) {
21	for _, count := range []int{10, 1000} {
22		t.Run(fmt.Sprintf("n=%d", count), func(t *testing.T) {
23			testGetdirentries(t, count)
24		})
25	}
26}
27func testGetdirentries(t *testing.T, count int) {
28	if count > 100 && testing.Short() && os.Getenv("GO_BUILDER_NAME") == "" {
29		t.Skip("skipping in -short mode")
30	}
31	d := t.TempDir()
32	var names []string
33	for i := 0; i < count; i++ {
34		names = append(names, fmt.Sprintf("file%03d", i))
35	}
36
37	// Make files in the temp directory
38	for _, name := range names {
39		err := os.WriteFile(filepath.Join(d, name), []byte("data"), 0)
40		if err != nil {
41			t.Fatalf("WriteFile: %v", err)
42		}
43	}
44
45	// Read files using Getdirentries
46	var names2 []string
47	fd, err := syscall.Open(d, syscall.O_RDONLY, 0)
48	if err != nil {
49		t.Fatalf("Open: %v", err)
50	}
51	defer syscall.Close(fd)
52	var base uintptr
53	var buf [2048]byte
54	for {
55		n, err := syscall.Getdirentries(fd, buf[:], &base)
56		if err != nil {
57			t.Fatalf("Getdirentries: %v", err)
58		}
59		if n == 0 {
60			break
61		}
62		data := buf[:n]
63		for len(data) > 0 {
64			// If multiple Dirents are written into buf, sometimes when we reach the final one,
65			// we have cap(buf) < Sizeof(Dirent). So use an appropriate slice to copy from data.
66			var dirent syscall.Dirent
67			copy((*[unsafe.Sizeof(dirent)]byte)(unsafe.Pointer(&dirent))[:], data)
68
69			data = data[dirent.Reclen:]
70			name := make([]byte, dirent.Namlen)
71			for i := 0; i < int(dirent.Namlen); i++ {
72				name[i] = byte(dirent.Name[i])
73			}
74			names2 = append(names2, string(name))
75		}
76	}
77
78	names = append(names, ".", "..") // Getdirentries returns these also
79	slices.Sort(names)
80	slices.Sort(names2)
81	if strings.Join(names, ":") != strings.Join(names2, ":") {
82		t.Errorf("names don't match\n names: %q\nnames2: %q", names, names2)
83	}
84}
85