term_darwin.go RawHistoryFolder

1//go:build darwin
2
3package rawterm
4
5import (
6	"bytes"
7	"fmt"
8	"os"
9	"syscall"
10	"unsafe"
11)
12
13const (
14	// TIOCGETA and TIOCSETA are Darwin's termios ioctl requests. They differ
15	// from the Linux TCGETS and TCSETS requests despite operating on the same
16	// syscall.Termios type.
17	reqGetTermios = syscall.TIOCGETA
18	reqSetTermios = syscall.TIOCSETA
19)
20
21// PreparePty grants and unlocks the slave associated with masterFD, obtains
22// its name from the kernel, and opens it. Darwin requires this exact sequence:
23// TIOCPTYGRANT before TIOCPTYUNLK before TIOCPTYGNAME.
24func PreparePty(masterFD int) (*os.File, error) {
25	if err := ioctl(masterFD, syscall.TIOCPTYGRANT, nil); err != nil {
26		return nil, fmt.Errorf("rawterm: grant pty: %w", err)
27	}
28	if err := ioctl(masterFD, syscall.TIOCPTYUNLK, nil); err != nil {
29		return nil, fmt.Errorf("rawterm: unlock pty: %w", err)
30	}
31
32	var slaveName [128]byte
33	if err := ioctl(masterFD, syscall.TIOCPTYGNAME, unsafe.Pointer(&slaveName[0])); err != nil {
34		return nil, fmt.Errorf("rawterm: get pty name: %w", err)
35	}
36	nul := bytes.IndexByte(slaveName[:], 0)
37	if nul < 0 {
38		return nil, fmt.Errorf("rawterm: get pty name: unterminated slave name")
39	}
40	if nul == 0 {
41		return nil, fmt.Errorf("rawterm: get pty name: empty slave name")
42	}
43
44	name := string(slaveName[:nul])
45	slave, err := os.OpenFile(name, os.O_RDWR|syscall.O_NOCTTY, 0)
46	if err != nil {
47		return nil, fmt.Errorf("rawterm: open %s: %w", name, err)
48	}
49	return slave, nil
50}