Added support for FreeBSD (copy pty_linux.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
+}
