1.\"- 2.\" SPDX-License-Identifer: BSD-2-Clause 3.\" 4.\" Copyright (c) 2001 Jonathan Lemon <jlemon@FreeBSD.org> 5.\" All rights reserved. 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.Dd July 7, 2024 29.Dt CONSCONTROL 8 30.Os 31.Sh NAME 32.Nm conscontrol 33.Nd control physical system video console devices 34.Sh SYNOPSIS 35.Nm 36.Op Cm list 37.Nm 38.Cm mute on | off 39.Nm 40.Cm add | delete 41.Ar console 42.Nm 43.Cm set | unset Ar console 44.Sh DESCRIPTION 45The 46.Nm 47utility is used to examine and modify the physical devices which back 48the virtual console devices. 49If no arguments 50(or only the 51.Cm list 52command) 53are specified, 54the current console settings are shown. 55.Pp 56There are two types of logical consoles; a high level console which 57is represented by 58.Pa /dev/console , 59and a low level console. 60The low level console is used for kernel 61.Xr printf 9 62and 63.Xr ddb 4 64debugger support, 65while the high level console is used by user programs like 66.Xr syslogd 8 . 67Multiple device support is implemented only for the low level console; 68the high level console is set to the first device in the console list. 69.Pp 70Multiple console support may be invoked by passing the kernel the 71.Fl D 72flag from the boot loader, or by using 73.Nm 74to change the list of console devices after the system has booted. 75.Pp 76The following options are available: 77.Bl -tag -width indent 78.It Cm add | delete Ar console 79Add or delete a physical device from the logical console. 80The device must support low-level console operations. 81Adding a device will place it at the front of the list of console 82devices; the first device is used for the high level console. 83.Pp 84The 85.Ar console 86argument 87is the name of a console device in 88.Pa /dev ; 89the name of the directory may be omitted. 90.It Cm mute on | off 91Change the state of console muting. 92All console output is suppressed when console muting is 93.Cm on . 94.It Cm set | unset Ar console 95Set or unset the virtual console. 96When unset, output from the system, such as the kernel 97.Xr printf 9 , 98always goes out to the real main console. 99When set, it goes to another. 100This is an interface to the tty ioctl 101.Dv TIOCCONS . 102.El 103.Sh SEE ALSO 104.Xr syscons 4 , 105.Xr tty 4 , 106.Xr vt 4 , 107.Xr boot 8 , 108.Xr loader 8 109.Sh HISTORY 110The 111.Nm 112utility first appeared in 113.Fx 5.0 . 114.Sh AUTHORS 115.An Jonathan Lemon 116