1.\" Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org> 2.\" All rights reserved. 3.\" 4.\" Portions of this software were developed under sponsorship from Snow 5.\" B.V., the Netherlands. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" $FreeBSD$ 29.\" 30.Dd August 20, 2008 31.Dt PTY 4 32.Os 33.Sh NAME 34.Nm pty 35.Nd BSD-style compatibility pseudo-terminal driver 36.Sh SYNOPSIS 37.Cd "device pty" 38.Sh DESCRIPTION 39The 40.Nm 41driver provides support for the traditional BSD naming scheme that was 42used for accessing pseudo-terminals. 43When the device 44.Pa /dev/ptyXX 45is being opened, a new terminal shall be created with the 46.Xr pts 4 47driver. 48A device node for this terminal shall be created, which has the name 49.Pa /dev/ttyXX . 50.Pp 51New code should not try to allocate pseudo-terminals using this 52interface. 53It is only provided for compatibility with older C libraries 54that tried to open such devices when 55.Xr posix_openpt 2 56was being called. 57.Sh FILES 58The BSD-style compatibility pseudo-terminal driver uses the following 59device names: 60.Pp 61.Bl -tag -width ".Pa /dev/pty[l-sL-S][0-9a-v]" 62.It Pa /dev/pty[l-sL-S][0-9a-v] 63Pseudo-terminal master devices. 64.It Pa /dev/tty[l-sL-S][0-9a-v] 65Pseudo-terminal slave devices. 66.El 67.Sh DIAGNOSTICS 68None. 69.Sh SEE ALSO 70.Xr posix_openpt 2 , 71.Xr pts 4 , 72.Xr tty 4 73.Sh HISTORY 74A 75pseudo-terminal driver appeared in 76.Bx 4.2 . 77.Sh BUGS 78Unlike previous implementations, the master slave device nodes are 79destroyed when the PTY becomes unused. 80A call to 81.Xr stat 2 82on a nonexistent master device will already cause a new master device 83node to be created. 84The master device can only be destroyed by opening and closing it. 85.Pp 86The 87.Nm 88driver cannot be unloaded, because it cannot determine if it is being 89used. 90