.TH CONSOLEFS 4
.SH NAME
consolefs, C  \- file system for console access
.SH SYNOPSIS
.B aux/consolefs
.I name
.I dev
[
.I name
.I dev
\&...
]
.PP
.B C
.I system
.SH DESCRIPTION
To ease administration of multiple machines one might attach
many serial console lines to a single computer.
.I Consolefs
is a file system that lets multiple users simultaneously access
these console lines.
Each
.IR name / dev
pair represents the name of a console and the serial line device
associated with it.
.I Consolefs
presents a single level directory with two files
per console:
.I name
and
.IB name ctl\f1.
Writes of
.I name
are equivalent to writes of
.I dev
and reads and writes of
.IB name ctl
are equivalent to reads and writes of
.IB dev ctl\f1.
.I Consolefs
broadcasts anything it reads from
.I dev
to all readers of
.IR name .
Therefore, many users can
.IR con (1)
to a 
.IR name ,
see all console output, and enter commands to the console.
.PP
To keep users from inadvertently interfering with one another,
notification is broadcast to all readers whenever a user
opens or closes
.IR name .
For example, if user
.B boris
opens a console that users
.B vlad
and
.B barney
have already opened, all will read the message:
.PP
.EX
	[+boris, vlad, barney]
.EE
.PP
If
.B vlad
then closes,
.B boris
and 
.B barney
will read:
.PP
.EX
	[-vlad, boris, barney]
.EE
.PP
.I Consolefs
posts the client end of its 9P channel in
.BR /srv/consolefs ;
.B mount
(see
.IR bind (1))
this file to see the consoles.
An example of 2 consoles complete with console logging is:
.IP
.EX
% aux/consolefs bootes /dev/eia0 fornax /dev/eia1
% mount /srv/consoles /mnt/consoles
% ls -p /mnt/consoles
bootes
bootesctl
fornax
fornaxctl
% cat /mnt/consoles/fornax >> /sys/log/fornax &
% cat /mnt/consoles/bootes >> /sys/log/bootes &
.EE
.PP
The
.IR rc (1)
script
.B C
automates this procedure.
It uses
.IR import (4)
to connect to
.B /mnt/consoles
on the machine connected to all the consoles, then uses
.IR con (1)
to connect to the console of the machine
.IR system.
The script must be edited at installation
by the local administration to identify the
system that holds
.BR /mnt/consoles .
.SH FILES
.TF /srv/consoles
.TP
.B /srv/consoles
Client end of pipe to server.
.SH SOURCE
.B /sys/src/cmd/aux/consolefs.l
.br
.B /rc/bin/C