From 76284c52ce4793067f046646ef9dd58a39e68846 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kim=20=22BKC=22=20Carlb=C3=A4cker?=
 <kim.carlbacker@gmail.com>
Date: Sat, 25 Jan 2014 02:42:27 +0100
Subject: [PATCH] Added support for FreeBSD (copy pty_linux.go)

---
 pty_freebsd.go | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 pty_freebsd.go

diff --git a/pty_freebsd.go b/pty_freebsd.go
new file mode 100644
index 0000000..13b64d7
--- /dev/null
+++ b/pty_freebsd.go
@@ -0,0 +1,53 @@
+package pty
+
+import (
+	"os"
+	"strconv"
+	"syscall"
+	"unsafe"
+)
+
+const (
+	sys_TIOCGPTN   = 0x4004740F
+	sys_TIOCSPTLCK = 0x40045431
+)
+
+func open() (pty, tty *os.File, err error) {
+	p, err := os.OpenFile("/dev/ptmx", os.O_RDWR, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	sname, err := ptsname(p)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	t, err := os.OpenFile(sname, os.O_RDWR|syscall.O_NOCTTY, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+	return p, t, nil
+}
+
+func ptsname(f *os.File) (string, error) {
+	var n int
+	err := ioctl(f.Fd(), sys_TIOCGPTN, &n)
+	if err != nil {
+		return "", err
+	}
+	return "/dev/pts/" + strconv.Itoa(n), nil
+}
+
+func ioctl(fd uintptr, cmd uintptr, data *int) error {
+	_, _, e := syscall.Syscall(
+		syscall.SYS_IOCTL,
+		fd,
+		cmd,
+		uintptr(unsafe.Pointer(data)),
+	)
+	if e != 0 {
+		return syscall.ENOTTY
+	}
+	return nil
+}