| // Copyright 2023 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| //go:build freebsd || linux || netbsd || openbsd |
| // +build freebsd linux netbsd openbsd |
| |
| package unix_test |
| |
| import ( |
| "os" |
| "path/filepath" |
| "runtime" |
| "testing" |
| |
| "golang.org/x/sys/unix" |
| ) |
| |
| func TestDup3(t *testing.T) { |
| tempFile, err := os.Create(filepath.Join(t.TempDir(), "TestDup")) |
| if err != nil { |
| t.Fatal(err) |
| } |
| defer tempFile.Close() |
| oldFd := int(tempFile.Fd()) |
| |
| // On NetBSD, it is not an error if oldFd == newFd |
| if runtime.GOOS != "netbsd" { |
| if got, want := unix.Dup3(oldFd, oldFd, 0), unix.EINVAL; got != want { |
| t.Fatalf("Dup3: expected err %v, got %v", want, got) |
| } |
| } |
| |
| // Create and reserve a file descriptor. |
| // Dup3 automatically closes it before reusing it. |
| nullFile, err := os.Open("/dev/null") |
| if err != nil { |
| t.Fatalf("Open failed: %v", err) |
| } |
| defer nullFile.Close() |
| newFd := int(nullFile.Fd()) |
| |
| err = unix.Dup3(oldFd, newFd, 0) |
| if err != nil { |
| t.Fatalf("Dup3: %v", err) |
| } |
| |
| b1 := []byte("Test123") |
| b2 := make([]byte, 7) |
| _, err = unix.Write(newFd, b1) |
| if err != nil { |
| t.Fatalf("Write to Dup3 fd failed: %v", err) |
| } |
| _, err = unix.Seek(oldFd, 0, 0) |
| if err != nil { |
| t.Fatalf("Seek failed: %v", err) |
| } |
| _, err = unix.Read(oldFd, b2) |
| if err != nil { |
| t.Fatalf("Read back failed: %v", err) |
| } |
| if string(b1) != string(b2) { |
| t.Errorf("Dup3: read %q from file, want %q", string(b2), string(b1)) |
| } |
| } |