r0, _, _ := syscall6(uintptr(unsafe.Pointer(&libc_Getpgrp)), 0, 0, 0, 0, 0, 0, 0)
	pgrp = int(r0)
	return
}

func Tcgetpgrp(fd int) (pgid int32, err error) {
	if errno := ioctlPtr(uintptr(fd), TIOCGPGRP, unsafe.Pointer(&pgid)); errno != 0 {
		return -1, errno
	}
	return pgid, nil
}

func Tcsetpgrp(fd int, pgid int32) (err error) {
	return ioctlPtr(uintptr(fd), TIOCSPGRP, unsafe.Pointer(&pgid))

import (
	"unsafe"
)

// pgid should really be pid_t, however _C_int (aka int32) is generally
// equivalent.

func Tcgetpgrp(fd int) (pgid int32, err error) {
	if err := ioctlPtr(fd, TIOCGPGRP, unsafe.Pointer(&pgid)); err != nil {
		return -1, err
	}
	return pgid, nil
}

func Tcsetpgrp(fd int, pgid int32) (err error) {
	return ioctlPtr(fd, TIOCSPGRP, unsafe.Pointer(&pgid))

	Prlimit           = prlimit
)

const (
	Sys_GETEUID = sys_GETEUID
)

func Tcgetpgrp(fd int) (pgid int32, err error) {
	_, _, errno := Syscall6(SYS_IOCTL, uintptr(fd), uintptr(TIOCGPGRP), uintptr(unsafe.Pointer(&pgid)), 0, 0, 0)
	if errno != 0 {
		return -1, errno
	}
	return pgid, nil
}

func Tcsetpgrp(fd int, pgid int32) (err error) {

// license that can be found in the LICENSE file.

package unix

import (
	"syscall"
	"unsafe"
)

// Note that pgid should really be pid_t, however _C_int (aka int32) is
// generally equivalent.

func Tcsetpgrp(fd int, pgid int32) (err error) {
	_, _, errno := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), uintptr(syscall.TIOCSPGRP), uintptr(unsafe.Pointer(&pgid)), 0, 0, 0)
	if errno != 0 {
		return errno
	}
	return nil

	r0, _, _ := sysvicall6(uintptr(unsafe.Pointer(&libc_Getpgrp)), 0, 0, 0, 0, 0, 0, 0)
	pgrp = int(r0)
	return
}

func Tcgetpgrp(fd int) (pgid int32, err error) {
	if errno := ioctlPtr(uintptr(fd), TIOCGPGRP, unsafe.Pointer(&pgid)); errno != 0 {
		return -1, errno
	}
	return pgid, nil
}

func Tcsetpgrp(fd int, pgid int32) (err error) {
	return ioctlPtr(uintptr(fd), TIOCSPGRP, unsafe.Pointer(&pgid))

)

//go:linkname ioctlPtr syscall.ioctlPtr
func ioctlPtr(fd int, req uint, arg unsafe.Pointer) (err error)

// Note that pgid should really be pid_t, however _C_int (aka int32) is
// generally equivalent.

func Tcsetpgrp(fd int, pgid int32) (err error) {
	return ioctlPtr(fd, syscall.TIOCSPGRP, unsafe.Pointer(&pgid))

		if err := unix.Tcsetpgrp(ptyFD, pgrp); err != nil {
			return fmt.Errorf("error setting tty process group: %w", err)
		}

		// Give the kernel time to potentially wake readers and have
		// them return EINTR (darwin does this).
		time.Sleep(pause)

		// Give TTY back.
		pid := int32(cmd.Process.Pid) // assume that pid_t is int32
		if err := unix.Tcsetpgrp(ptyFD, pid); err != nil {

	// This is just best effort.
	syscall.Tcsetpgrp(ttyFD, fpgrp)
}

func TestForegroundSignal(t *testing.T) {
	tty, err := os.OpenFile("/dev/tty", os.O_RDWR, 0)
	if err != nil {
		t.Skipf("couldn't open /dev/tty: %s", err)
	}
	defer tty.Close()

	ttyFD := int(tty.Fd())

	fpgrp, err := syscall.Tcgetpgrp(ttyFD)
	if err != nil {
		t.Fatalf("Tcgetpgrp failed: %v", err)
	}
	if fpgrp == 0 {