186d7f5d3SJohn Marino.\" Copyright (c) 2001 286d7f5d3SJohn Marino.\" The FreeBSD Project 386d7f5d3SJohn Marino.\" 486d7f5d3SJohn Marino.\" Redistribution and use in source and binary forms, with or without 586d7f5d3SJohn Marino.\" modification, are permitted provided that the following conditions 686d7f5d3SJohn Marino.\" are met: 786d7f5d3SJohn Marino.\" 1. Redistributions of source code must retain the above copyright 886d7f5d3SJohn Marino.\" notice, this list of conditions and the following disclaimer. 986d7f5d3SJohn Marino.\" 1086d7f5d3SJohn Marino.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 1186d7f5d3SJohn Marino.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1286d7f5d3SJohn Marino.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1386d7f5d3SJohn Marino.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 1486d7f5d3SJohn Marino.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1586d7f5d3SJohn Marino.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 1686d7f5d3SJohn Marino.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 1786d7f5d3SJohn Marino.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 1886d7f5d3SJohn Marino.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 1986d7f5d3SJohn Marino.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2086d7f5d3SJohn Marino.\" SUCH DAMAGE. 2186d7f5d3SJohn Marino.\" 2286d7f5d3SJohn Marino.\" $FreeBSD: src/share/man/man4/nmdm.4,v 1.2.2.1 2001/08/11 00:54:14 mp Exp $ 2386d7f5d3SJohn Marino.\" $DragonFly: src/share/man/man4/nmdm.4,v 1.2 2003/06/17 04:36:59 dillon Exp $ 2486d7f5d3SJohn Marino.\" 2586d7f5d3SJohn Marino.Dd July 7, 2001 2686d7f5d3SJohn Marino.Dt NMDM 4 2786d7f5d3SJohn Marino.Os 2886d7f5d3SJohn Marino.Sh NAME 2986d7f5d3SJohn Marino.Nm nmdm 3086d7f5d3SJohn Marino.Nd nullmodem terminal driver 3186d7f5d3SJohn Marino.Sh SYNOPSIS 3286d7f5d3SJohn Marino.Cd "device nmdm" 3386d7f5d3SJohn Marino.Sh DESCRIPTION 3486d7f5d3SJohn MarinoThe 3586d7f5d3SJohn Marino.Nm 3686d7f5d3SJohn Marinodriver provides support for a device-pair termed a 3786d7f5d3SJohn Marino.Em null modem pair . 3886d7f5d3SJohn MarinoA null modem pair is a pair of character devices. 3986d7f5d3SJohn MarinoEach device provides to a process an interface identical 4086d7f5d3SJohn Marinoto that described in 4186d7f5d3SJohn Marino.Xr tty 4 . 4286d7f5d3SJohn MarinoHowever, whereas most other devices which provide the 4386d7f5d3SJohn Marinointerface described in 4486d7f5d3SJohn Marino.Xr tty 4 4586d7f5d3SJohn Marinohave a hardware device of some sort behind them, the 4686d7f5d3SJohn Marino.Nm 4786d7f5d3SJohn Marinodevice has, instead, another process manipulating 4886d7f5d3SJohn Marinoit through the other half of the pair. 4986d7f5d3SJohn MarinoThat is, anything written on the first device is 5086d7f5d3SJohn Marinogiven to the second device as input and anything written 5186d7f5d3SJohn Marinoon the second device is presented as input on the first 5286d7f5d3SJohn Marinodevice. 5386d7f5d3SJohn Marino.Sh FILES 5486d7f5d3SJohn Marino.Bl -tag -width /dev/nmdm[N][AB] -compact 5586d7f5d3SJohn Marino.It Pa /dev/nmdm Ns Ar N Ns Op Pa AB 5686d7f5d3SJohn Marinonullmodem device nodes. 5786d7f5d3SJohn MarinoWhere the 5886d7f5d3SJohn Marino.Pa A 5986d7f5d3SJohn Marinonode has a matching 6086d7f5d3SJohn Marino.Pa B 6186d7f5d3SJohn Marinonode. 6286d7f5d3SJohn Marino.El 6386d7f5d3SJohn Marino.Sh DIAGNOSTICS 6486d7f5d3SJohn MarinoNone. 6586d7f5d3SJohn Marino.Sh SEE ALSO 6686d7f5d3SJohn Marino.Xr tty 4 6786d7f5d3SJohn Marino.Sh HISTORY 6886d7f5d3SJohn MarinoThe 6986d7f5d3SJohn Marino.Nm 7086d7f5d3SJohn Marinodriver first appeared in 7186d7f5d3SJohn Marino.Fx 4.4 . 72