blob: 4ed3eb44e17131ac66fd31c6e0c496dc2f23dfd9 [file] [log] [blame]
// Copyright 2017 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 (aix || darwin || dragonfly || freebsd || hurd || (linux && !android) || netbsd || openbsd || solaris) && cgo
// +build aix darwin dragonfly freebsd hurd linux,!android netbsd openbsd solaris
// +build cgo
// Package pty is a simple pseudo-terminal package for Unix systems,
// implemented by calling C functions via cgo.
// This is only used for testing the os/signal package.
package pty
import (
"fmt"
"os"
"syscall"
"unsafe"
)
//extern posix_openpt
func posix_openpt(int32) int32
//extern grantpt
func grantpt(int32) int32
//extern unlockpt
func unlockpt(int32) int32
//extern ptsname
func ptsname(int32) *byte
//extern close
func close(int32) int32
const _O_RDWR = 2
type PtyError struct {
FuncName string
ErrorString string
Errno syscall.Errno
}
func ptyError(name string, err error) *PtyError {
return &PtyError{name, err.Error(), err.(syscall.Errno)}
}
func (e *PtyError) Error() string {
return fmt.Sprintf("%s: %s", e.FuncName, e.ErrorString)
}
func (e *PtyError) Unwrap() error { return e.Errno }
// Open returns a control pty and the name of the linked process tty.
func Open() (pty *os.File, processTTY string, err error) {
m := posix_openpt(_O_RDWR)
if m < 0 {
return nil, "", ptyError("posix_openpt", syscall.GetErrno())
}
if grantpt(m) < 0 {
errno := syscall.GetErrno()
close(m)
return nil, "", ptyError("grantpt", errno)
}
if unlockpt(m) < 0 {
errno := syscall.GetErrno()
close(m)
return nil, "", ptyError("unlockpt", errno)
}
p := ptsname(m)
s := (*[32000]byte)(unsafe.Pointer(p))[:]
for i, v := range s {
if v == 0 {
s = s[:i:i]
break
}
}
processTTY = string(s)
return os.NewFile(uintptr(m), "pty"), processTTY, nil
}