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CONSCONTROL(8) FreeBSD System Manager's Manual CONSCONTROL(8)
NAME
conscontrol - control physical console devices
SYNOPSIS
conscontrol [list]
conscontrol mute on | off
conscontrol add | delete console
conscontrol set | unset console
DESCRIPTION
The conscontrol utility is used to examine and modify the physical
devices which back the virtual console devices. If no arguments (or only
the list command) are specified, the current console settings are shown.
There are two types of logical consoles; a high level console which is
represented by /dev/console, and a low level console. The low level
console is used for kernel printf(9) and ddb(4) debugger support, while
the high level console is used by user programs like syslogd(8).
Multiple device support is implemented only for the low level console;
the high level console is set to the first device in the console list.
Multiple console support may be invoked by passing the kernel the -D flag
from the boot loader, or by using conscontrol to change the list of
console devices after the system has booted.
The following options are available:
add | delete console
Add or delete a physical device from the logical console. The
device must support low-level console operations. Adding a
device will place it at the front of the list of console devices;
the first device is used for the high level console.
The console argument is the name of a console device in /dev; the
name of the directory may be omitted.
mute on | off
Change the state of console muting. All console output is
suppressed when console muting is on.
set | unset console
Set or unset the virtual console. When unset, output from the
system, such as the kernel printf(9), always goes out to the real
main console. When set, it goes to another. This is an
interface to the tty ioctl TIOCCONS.
SEE ALSO
syscons(4), tty(4), vt(4), boot(8), loader(8)
HISTORY
The conscontrol utility first appeared in FreeBSD 5.0.
AUTHORS
Jonathan Lemon
FreeBSD 14.0-RELEASE-p11 April 14, 2011 FreeBSD 14.0-RELEASE-p11