1*86d7f5d3SJohn Marino.\" Copyright (c) 2001 2*86d7f5d3SJohn Marino.\" The FreeBSD Project 3*86d7f5d3SJohn Marino.\" 4*86d7f5d3SJohn Marino.\" Redistribution and use in source and binary forms, with or without 5*86d7f5d3SJohn Marino.\" modification, are permitted provided that the following conditions 6*86d7f5d3SJohn Marino.\" are met: 7*86d7f5d3SJohn Marino.\" 1. Redistributions of source code must retain the above copyright 8*86d7f5d3SJohn Marino.\" notice, this list of conditions and the following disclaimer. 9*86d7f5d3SJohn Marino.\" 10*86d7f5d3SJohn Marino.\" THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 11*86d7f5d3SJohn Marino.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 12*86d7f5d3SJohn Marino.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 13*86d7f5d3SJohn Marino.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 14*86d7f5d3SJohn Marino.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 15*86d7f5d3SJohn Marino.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 16*86d7f5d3SJohn Marino.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 17*86d7f5d3SJohn Marino.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 18*86d7f5d3SJohn Marino.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 19*86d7f5d3SJohn Marino.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 20*86d7f5d3SJohn Marino.\" SUCH DAMAGE. 21*86d7f5d3SJohn Marino.\" 22*86d7f5d3SJohn Marino.\" $FreeBSD: src/share/man/man4/nmdm.4,v 1.2.2.1 2001/08/11 00:54:14 mp Exp $ 23*86d7f5d3SJohn Marino.\" $DragonFly: src/share/man/man4/nmdm.4,v 1.2 2003/06/17 04:36:59 dillon Exp $ 24*86d7f5d3SJohn Marino.\" 25*86d7f5d3SJohn Marino.Dd July 7, 2001 26*86d7f5d3SJohn Marino.Dt NMDM 4 27*86d7f5d3SJohn Marino.Os 28*86d7f5d3SJohn Marino.Sh NAME 29*86d7f5d3SJohn Marino.Nm nmdm 30*86d7f5d3SJohn Marino.Nd nullmodem terminal driver 31*86d7f5d3SJohn Marino.Sh SYNOPSIS 32*86d7f5d3SJohn Marino.Cd "device nmdm" 33*86d7f5d3SJohn Marino.Sh DESCRIPTION 34*86d7f5d3SJohn MarinoThe 35*86d7f5d3SJohn Marino.Nm 36*86d7f5d3SJohn Marinodriver provides support for a device-pair termed a 37*86d7f5d3SJohn Marino.Em null modem pair . 38*86d7f5d3SJohn MarinoA null modem pair is a pair of character devices. 39*86d7f5d3SJohn MarinoEach device provides to a process an interface identical 40*86d7f5d3SJohn Marinoto that described in 41*86d7f5d3SJohn Marino.Xr tty 4 . 42*86d7f5d3SJohn MarinoHowever, whereas most other devices which provide the 43*86d7f5d3SJohn Marinointerface described in 44*86d7f5d3SJohn Marino.Xr tty 4 45*86d7f5d3SJohn Marinohave a hardware device of some sort behind them, the 46*86d7f5d3SJohn Marino.Nm 47*86d7f5d3SJohn Marinodevice has, instead, another process manipulating 48*86d7f5d3SJohn Marinoit through the other half of the pair. 49*86d7f5d3SJohn MarinoThat is, anything written on the first device is 50*86d7f5d3SJohn Marinogiven to the second device as input and anything written 51*86d7f5d3SJohn Marinoon the second device is presented as input on the first 52*86d7f5d3SJohn Marinodevice. 53*86d7f5d3SJohn Marino.Sh FILES 54*86d7f5d3SJohn Marino.Bl -tag -width /dev/nmdm[N][AB] -compact 55*86d7f5d3SJohn Marino.It Pa /dev/nmdm Ns Ar N Ns Op Pa AB 56*86d7f5d3SJohn Marinonullmodem device nodes. 57*86d7f5d3SJohn MarinoWhere the 58*86d7f5d3SJohn Marino.Pa A 59*86d7f5d3SJohn Marinonode has a matching 60*86d7f5d3SJohn Marino.Pa B 61*86d7f5d3SJohn Marinonode. 62*86d7f5d3SJohn Marino.El 63*86d7f5d3SJohn Marino.Sh DIAGNOSTICS 64*86d7f5d3SJohn MarinoNone. 65*86d7f5d3SJohn Marino.Sh SEE ALSO 66*86d7f5d3SJohn Marino.Xr tty 4 67*86d7f5d3SJohn Marino.Sh HISTORY 68*86d7f5d3SJohn MarinoThe 69*86d7f5d3SJohn Marino.Nm 70*86d7f5d3SJohn Marinodriver first appeared in 71*86d7f5d3SJohn Marino.Fx 4.4 . 72