conserver/console/console.man

.\" $Id: console.man,v 1.66 2015/06/02 17:19:31 bryan Exp $
.TH CONSOLE 1 "2015/06/02" "conserver-8.2.1" "conserver"
.SH NAME
console \- console server client program
.SH SYNOPSIS
.B console
.RI [ generic-args ]
.RB [ \-aAfFsS ]
.BR [ \-e
.IR esc ]
.I console
.br
.B console
.RI [ generic-args ]
.RB [ \-iIuwWx ]
.RI [ console ]
.br
.B console
.RI [ generic-args ]
.RB [ \-hPqQrRV ]
.RB [ \- [ bB ]
.IR message ]
.RB [ \-d
.RI [ user ][\f3@\fP console ]]
.RB [ \-t
.RI [ user ][\f3@\fP console ]
.IR message ]
.RB [ \- [ zZ ]
.IR cmd ]
.PP
.IR generic-args :
.RB [ \-7DEnUv ]
.RB [ \-c
.IR cred ]
.RB [ \-C
.IR config ]
.BR [ \-M
.IR master ]
.BR [ \-p
.IR port ]
.BR [ \-l
.IR user ]
.SH DESCRIPTION
.B Console
is used to manipulate console terminals remotely or to poll running
.BR conserver (8)
daemons for status information.
.PP
In the first form above,
.B console
asks the user's password before
granting interactive access to a console (on a non-trusted system),
since such a session may provide single-user access.
If the server's autocompletion feature is enabled,
only as much of the console name as is required to
identify it uniquely to the server is required.
.PP
For non-interactive options,
.B console
outputs only the requested information and exits.
.PP
.B Console
knows only of a primary
.B conserver
host (see the
.B \-M
option below), to which it initially connects.
In a multi-server environment, the primary server may refer
the client to a different server handling the requested console,
or it will provide a list of all servers if required (as when
.B console
is invoked with the
.B \-r
option).
.B Console
then opens connections to the appropriate server(s).
It is not necessary for the user of
.B console
to know which server manages which consoles, as long as
.B console
knows a valid primary server
and all available consoles are listed in the primary server's
configuration file.
.SH OPTIONS
.PP
Options may be given as separate arguments (e.g.,
.B \-v
.BR \-w )
or clustered (e.g.,
.BR \-vw ).
Options and their arguments may be separated by optional white space.
Option arguments containing spaces or other characters special to the shell
must be quoted.
.TP 11
.B \-7
Strip the high bit off of all data received, whether from user
input or from the server, before any processing occurs.
Disallows escape sequence characters with the high bit set.
.TP
.B \-a
Access a console with a two-way (read-write) connection (this is the default).
The connection is dropped to spy mode if someone else is attached read-write.
.TP
.BI \-b message
Broadcast a
.I message
to all users connected to each server.
.TP
.BI \-B message
Same as
.B \-b
but just send a
.I message
to users on the primary server.
.TP
.BI \-c cred
Load an SSL certificate and key from the PEM encoded file
.IR cred .
.TP
.BI \-C config
Use the per-user configuration file
.IR config .
.TP
.B \-d
Disconnect the users specified by
.IR user @ console .
You may specify the target as
.I user
(disconnect the
.IR user,
regardless of what console they are attached to),
.RI @ console
(disconnect all users attached to
.IR console ),
or
.IR user @ console
(disconnect the
.I user
attached to
.IR console ).
.TP
.B \-D
Enable debugging output.
.TP
.BI \-e esc
Set the initial two-character escape sequence to those represented by
.IR esc .
Any of the forms output by
.BR cat (1)'s
.B \-v
option are accepted.
The default value is
.RB `` ^Ec ''.
.TP
.B \-E
If encryption has been built into the code
.RB ( --with-openssl ),
encrypted client connections are, by default, a requirement.
This option disables any attempt at creating an
encrypted connection.
If you'd like to use encrypted connections when your server
supports it, but fallback to non-encrypted otherwise, the
.B \-U
option is what you want.
.TP
.B \-f
Same as
.B \-a
except it will force any existing connection into spy mode.
.TP
.B \-h
Display a brief help message.
.TP
.B \-i
Display status information in a machine-parseable format (see below for the details).
.TP
.B \-I
Same as
.B \-i
but just acts on the primary server.
.TP
.BI \-l user
Set the login name used for authentication to
.IR user .
By default,
.B console
uses $USER if its uid matches the user's real uid,
or $LOGNAME if its uid matches the user's real uid,
or else the name associated with the user's real uid.
.TP
.BI \-M master
The
.B console
client program polls
.I master
as the primary server,
rather than the default set at compile time (typically
.RB `` console '').
The default
.I master
may be changed at compile time using the
.B --with-master
option.
If
.B --with-uds
is used to enable Unix domain sockets, however, this option points
.B console
to the directory which holds those sockets.
The default
.I master
directory
.RB (`` /tmp/conserver '')
may be changed at compile time using the
.B --with-uds
option.
.TP
.BI \-n
Do not read the system-wide configuration file.
.TP
.BI \-p port
Set the port to connect to.
This may be either a port number
or a service name.
The default
.I port
may be changed at compile time
using the
.B --with-port
option.
If the
.B --with-uds
option was used, this option is ignored.
.TP
.B \-P
Display the pid of the master daemon process on each server.
.TP
.B \-q
The
.B console
client connects to each server to request that the
server daemon quit (shut down).
The root password of the host(s) running conserver is required
unless the local host is listed as ``trusted'' in the
conserver.cf file; in that case, just press <return>.
.TP
.B \-Q
Same as
.B \-q
but just acts on the primary server.
.TP
.B \-r
Display daemon versions.
The
.B console
client connects to each
server to request its version information.
.TP
.B \-R
Same as
.B \-r
but just acts on the primary server.
.TP
.B \-s
Request a read-only (spy mode) connection.
In this mode all the escape sequences (below) work, or report errors,
but all other keyboard input is discarded.
.TP
.B \-t
Send a text
.I message
to
.IR user @ console .
You may specify the target as
.I user
(send to
.IR user,
regardless of what console they are attached to),
.RI @ console
(send to all users attached to
.IR console ),
or
.IR user @ console
(send to
.I user
attached to
.IR console ).
.TP
.B \-u
Show a list of all consoles with status (`up', `down', or `init')
and attached users
.RI ( user @ host
if attached read-write, `<spies>' if only users in spy mode, or `<none>').
.TP
.B \-U
If encryption has been built into the code
.RB ( --with-openssl ),
encrypted client connections are, by default, a requirement.
This option allows the client to attempt an encrypted connection
but fall back to a non-encrypted connection if the server doesn't
support encryption.
If the encryption handshake is failing, disabling encryption on the
client with the
.B \-E
option is probably what you want.
.TP
.B \-v
Be more verbose when building the connection(s).
Use this option in combination with any of `show' options (below)
for added benefit.
.TP
.B \-V
Output the version and settings of the console client program
and then exit.
.TP
.B \-w
Show a list of all who are currently connected to consoles,
including the hostnames where the
.B console
connections originate and the idle times.
This is useful to see if anybody is actively
using the console system if it becomes necessary to shut down
.BR conserver .
.TP
.B \-W
Same as
.B \-w
but just acts on the primary server.
.TP
.B \-x
Show a list of consoles and devices.
.TP
.BI \-z cmd
Sends a command
.RI ( cmd )
to each server and displays the result.
The valid commands are:
.RS
.sp
.PD 0
.TP 12
.B bringup
Try to connect all consoles marked as down (this is equivalent
to sending the server a SIGUSR1)
.TP
.B SIGUSR1
Same as
.B bringup
.TP
.B help
Displays the help message
.TP
.B pid
Returns the pid of the server (this is equivalent to
.BR \-P )
.TP
.B quit
Instructs the server to shut down (this is equivalent to
.B \-q
or sending the server a SIGTERM)
.TP
.B SIGTERM
Same as
.B quit
.TP
.B reconfig
Instructs the server to reload the configuration file, then
perform the actions of
.B reopen
(this is equivalent to sending the server a SIGHUP)
.TP
.B SIGHUP
Same as
.B reconfig
.TP
.B reopen
Instructs the server to reopen all logfiles, then
perform the actions of
.B bringup
(this is equivalent to sending the server a SIGUSR2)
.TP
.B SIGUSR2
Same as
.B reopen
.TP
.B version
Returns the version of the server (this is equivalent to
.BR \-V )
.PD
.RE
.TP
.BI \-Z cmd
Same as
.B \-z
but just sends
.I cmd
to the primary server.
.PP
The
.BR \-A ,
.BR \-F ", or"
.B \-S
options have the same effect as their lower-case variants.
In addition, they each request the last 20 lines of the console output after
making the connection (as if
.RB `` ^Ecr ''
were typed).
.PP
The
.BR \-i ,
.BR \-u ,
.BR \-w ", and"
.B \-x
options can be given a console name, which will limit their output to that console.
.PP
The
.B \-i
option outputs status information regarding each console in 15 colon-separated fields.
.TP
.I name
The name of the console.
.TP
.I hostname,pid,socket
The hostname, pid, and socket number of the child process managing
the console.
.TP
.I type
The type of console.
Values will be a `/' for a local device, `|' for
a command, `!' for a remote port, `%' for a Unix domain socket,
and `#' for a noop console.
.TP
.I console-details
The details regarding the console.
The values here (all comma-separated) depend on the type of the console.
Local devices will have values of the device file, baud rate/parity, and
file descriptor for the device.
Commands will have values of the command, the command's pid, the
pseudo-tty, and file descriptor for the pseudo-tty.
Remote ports will have values of the remote hostname, remote port number,
``raw'' or ``telnet'' protocol, and file descriptor for the socket connection.
Unix domain sockets will have the path to the socket and the file
descriptor for the socket connection.
Noop consoles will have nothing.
.TP
.I users-list
The details of each user connected to the console.
The details for each
user are an `@' separated list of `w', `r', or `s' (for read-write, read-only,
or suspended), username, hostname the user is on, the user's idle time,
and (for `r' and `s' users only) ``rw'' or ``ro'' (if the user wants
read-write mode or not).
Each user bundle is separated by commas.
.TP
.I state
The state of the console.
Values with either be ``up'', ``down'', or ``init''.
.TP
.I perm
This value will either be ``rw'' or ``ro''.
It will only be ``ro'' if
the console is a local device (`/' type) and the permissions are such
that the server can open the file for read, but not write.
.TP
.I logfile-details
The details regarding the logging for the console.
The comma-separated
values will be the logfile, ``log'' or ``nolog'' (if logging is on
or not - toggled via ``^EcL''), ``act'' or ``noact'' (if activity logging is
enabled or not - the `a' timestamp option), the timestamp interval, and
the file descriptor of the logfile.
.TP
.I break
The default break sequence used for the console.
.TP
.I reup
If the console is currently down and the automatic reconnection code
is at work, it will have the value of ``autoup'', otherwise it
will be ``noautoup''.
.TP
.I aliases
The console aliases are presented in a comma-separated list.
.TP
.I options
The active options for the console are presented in a comma-separated list.
.TP
.I initcmd
The initcmd configuration option for the console.
.TP
.I idletimeout
The idletimeout configuration option for the console.
.TP
.I idlestring
The idlestring configuration option for the console.
.SH CONFIGURATION
.B Console
reads configuration information from the system-wide configuration file
.RB ( console.cf ),
then the per-user configuration file
.RB ( .consolerc ),
and then applies command-line arguments.
Each configuration location can override the previous.
The same happens when parsing an individual file - the later entries
always override the earlier entries.
Because of that, you should put ``global'' defaults first and
more specific defaults second.
.PP
The configuration file is read using the same parser as 
.BR conserver.cf (5),
and you should check that manpage for parser details.
.B Console
recognizes the following configuration blocks.
.TP
\f3config\fP \f2hostname\fP|\f2ipaddr\fP
.br
Define a configuration block for the client host named
.I hostname
or using the address
.IR ipaddr .
If the value of ``*'' is used, the configuration block will be applied to
all client hosts.
.RS
.TP
\f3escape\fP \f2esc\fP
.br
Set the escape sequence (see the
.B \-e
command-line flag).
.TP
\f3master\fP \f2master\fP
.br
Set the default master to
.I master
(see the
.B \-M
command-line flag).
.TP
\f3playback\fP \f2num\fP|\f3""\fP
.br
Override the playback length for the
.B p
escape command to
.I num
lines (if the server supports it).
Using the special value of ``0'' will cause the client to use the number
of lines of the current terminal (if that can be determined).
If the null string (``""'') is used, the playback length will not be overridden.
.TP
\f3port\fP \f2port\fP
.br
Set the default port to
.I port
(see the
.B \-p
command-line flag).
.TP
\f3replay\fP \f2num\fP|\f3""\fP
.br
Override the replay length for the
.B r
escape command to
.I num
lines (if the server supports it).
Using the special value of ``0'' will cause the client to use the number
of lines of the current terminal (if that can be determined).
If the null string (``""'') is used, the replay length will not be overridden.
.TP
\f3sslcacertificatefile\fP \f2filename\fP
.br
Load the valid CA certificates for the
.SM SSL
connection from the PEM encoded file.
.TP
\f3sslcacertificatepath\fP \f2directory\fP
.br
Load the valid CA certificates for the
.SM SSL
connection from the PEM encoded files in the directory.
.TP
\f3sslcredentials\fP \f2filename\fP
.br
Set the
.SM SSL
credentials file location (see the
.B \-c
command-line flag).
.TP
\f3sslenabled\fP \f3yes\fP|\f3true\fP|\f3on\fP|\f3no\fP|\f3false\fP|\f3off\fP
.br
Set whether or not encryption is attempted when talking to servers (see the
.B \-E
command-line flag).
.TP
\f3sslrequired\fP \f3yes\fP|\f3true\fP|\f3on\fP|\f3no\fP|\f3false\fP|\f3off\fP
.br
Set whether or not encryption is required when talking to servers (see the
.B \-U
command-line flag).
.TP
\f3striphigh\fP \f3yes\fP|\f3true\fP|\f3on\fP|\f3no\fP|\f3false\fP|\f3off\fP
.br
Set whether or not to strip the high bit off all data received
(see the
.B \-7
command-line flag).
.TP
\f3username\fP \f2user\fP
.br
Set the username passed to the server to
.I user
(see the
.B \-l
command-line flag).
.RE
.TP
\f3terminal\fP \f2type\fP
.br
Define a configuration block when using a terminal of type
.IR type .
If the value of ``*'' is used, the configuration block will be applied to
all terminal types.
.RS
.TP
\f3attach\fP \f2string\fP|\f3""\fP
.br
Set a
.I string
to print when successfully attached to a console.
Character substitions will be performed based on the
.B attachsubst
value and occur
.I before
interpretation of the special characters below.
If the null string (``\f3""\fP'') is used, no string will be printed.
.I string
is a simple character string with the exception of `\e'
and `^':
.RS
.RS
.sp
.PD 0
.TP 6
.B \ea
alert
.TP
.B \eb
backspace
.TP
.B \ef
form-feed
.TP
.B \en
newline
.TP
.B \er
carriage-return
.TP
.B \et
tab
.TP
.B \ev
vertical-tab
.TP
.B \e\e
backslash
.TP
.B \e^
circumflex
.TP
.BI \e ooo
octal representation of a character (where
.I ooo
is one to three octal digits)
.TP
.BI \e c
character
.I c
.TP
.B ^?
delete
.TP
.BI ^ c
control character
.RI ( c
is ``and''ed with 0x1f)
.PD
.RE
.RE
.IP
An interesting use of
.B attach
and
.B attachsubst
would be:
.RS
.IP
.ft CR
.nf
terminal xterm {
    attach "^[]0;conserver: U@C^G";
    attachsubst U=us,C=cs;
}
.fi
.ft
.RE
.TP
\f3attachsubst\fP \f2c\fP\f3=\fP\f2t\fP[\f2n\fP]\f2f\fP[\f3,\fP...]|\f3""\fP
.br
Perform character substitutions on the
.B attach
value.
A series of replacements can be defined by specifying a
comma-separated list of
\f2c\fP\f3=\fP\f2t\fP[\f2n\fP]\f2f\fP
sequences where
.I c
is any printable character,
.I t
specifies the replacement value,
.I n
is a field length (optional),
and
.I f
is the format string.
.I t
can be one of the characters below, catagorized as a string replacement
or a numeric replacement, which dictates the use of the
.I n
and
.I f
fields.
.RS
.RS
.sp
.PD 0
.TP
String Replacement
.TP
.B u
username
.TP
.B c
console name
.sp
.PP
Numeric Replacement
.TP
none available (yet)
.PD
.RE
.RE
.IP
For string replacements, if the replacement isn't at least
.I n
characters, it will be padded with space characters on the left.
.I f
must be `s'.
For numeric replacements, the value will be formatted to at least
.I n
characters, padded with 0s if
.I n
begins with a 0, and space characters otherwise.
.I f
must be either `d', `x' or `X', specifying a decimal, lower-case
hexadecimal, or an uppercase hexadecimal conversion.
If the null string (``\f3""\fP'') is used, no replacements will be done.
.TP
\f3detach\fP \f2string\fP|\f3""\fP
.br
Set a
.I string
to print once detached from a console.
Character substitions will be performed based on the
.B detachsubst
value.
See the
.B attach
option for an explanation of
.IR string .
If the null string (``\f3""\fP'') is used, no string will be printed.
.TP
\f3detachsubst\fP \f2c\fP\f3=\fP\f2t\fP[\f2n\fP]\f2f\fP[\f3,\fP...]|\f3""\fP
.br
Perform character substitutions on the
.B detach
value.
See the
.B attachsubst
option for an explanation of the format string.
.RE
.PP
A simple configuration to set a new default escape sequence and override
the master location would be:
.IP
.ft CR
.nf
# override options for all hosts
config * {
    master localhost;
    escape ^Ee;
}
# set things more specific to host1
# note: if the entries were reversed, host1
# would also use localhost.
config host1 {
    master console1;
}
.fi
.ft
.SH "ESCAPE SEQUENCES"
The connection can be controlled by a two-character escape sequence, followed
by a command.
The default escape sequence is ``control-E c''
(octal 005 143).
(The escape sequences are actually processed by the server; see the
.BR conserver (8)
man page for more information.)
Commands are:
.sp
.PD 0
.TP 13
.B \.
disconnect
.TP
.B ;
move to another console
.TP
.B a
attach read-write if nobody already is
.TP
.B b
send broadcast message to all users on this console
.TP
.B c
toggle flow control (don't do this)
.TP
.B d
down the current console
.TP
.BI e cc
change the escape sequence to the next two characters
.TP
.B f
forcibly attach read-write
.TP
.B g
group info
.TP
.B i
information dump
.TP
.B L
toggle logging on/off
.TP
.B l?
list the break sequences available
.TP
.B l0
send the break sequence associated with this console
.TP
.B l1-9a-z
send the specific break sequence
.TP
.B m
display the "message of the day"
.TP
.B o
close (if open) and reopen the line (to clear errors (silo overflows))
and the log file
.TP
.B p
playback the last 60 lines of output
.TP
.B P
set number of playback lines
.TP
.B r
replay the last 20 lines of output
.TP
.B R
set number of replay lines
.TP
.B s
switch to spy mode (read only)
.TP
.B u
show status of hosts/users in this group
.TP
.B v
show the version of the group server
.TP
.B w
who is using this console
.TP
.B x
examine this group's devices and modes
.TP
.B z
suspend this connection
.TP
.B !
invoke task
.TP
.B |
attach a local command to the console
.TP
.B ?
display list of commands
.TP
.BR ^M " (return)"
continue, ignore the escape sequence
.TP
.BR ^R " (ctrl-R)"
replay the last line only
.TP
.BI \e ooo
send character having octal code
.IR ooo " (must"
specify three octal digits)
.PD
.PP
If any other character is hit after the escape sequence, all three characters
will be discarded.
Note that a line break or a down command
can only be sent from a read-write connection.
To send the escape sequence through the connection one must redefine
the outer escape sequence, or use
.BI ^Ec\e ooo
to send the
first escape character before typing the second character directly.
.PP
In the
.B \-u
output, the login ``<none>'' indicates no one is
viewing that console, and the login ``<spies>'' indicates that
no one has a read-write connection (only read-only).
.PP
When running a local command via
.RB `` ^Ec| '',
you can type 
.RB ` ^C '
to send the command a SIGHUP,
.RB ` ^\e '
to send the command a SIGKILL, and
.RB ` o '
to toggle the display of the console data.
.SH EXAMPLES
.TP 15
console \-u
Outputs something like:
.IP
.ft CR
.nf
dumb      up      <none>
expert    up      ksb@mentor
tyro      up      <spies>
mentor    up      <none>
sage      up      fine@cis
.fi
.ft
.IP
The
.B <none>
indicates no one is viewing
.IR dumb
or
.IR mentor ,
the
.B <spies>
indicates only read-only connections exist for
.IR tyro ,
and other
.IR login @ host
entries indicate users attached read-write to
.I sage
and
.IR expert .
.TP
console \-w
Outputs something like:
.IP
.ft CR
.nf
ksb@extra       attach  2days     expert
file@cis        attach  21:46     sage
dmr@alice       spy     \00:04     tyro
.fi
.ft
.IP
The third column is the idle time of the user.
Either
.IR hours : minutes
or number of days is displayed.
.TP
console \-e "^[1" lv426
Requests a connection to the host ``lv426'' with the escape characters
set to ``escape one''.
.SH FILES
.PP
The following default file locations may be overridden
at compile time or by the command-line options described above.
Run
.B console \-V
to see the defaults set at compile time.
.PP
.PD 0
.TP 25
.B /etc/console.cf
system-wide configuration file
.TP
.B \s-1$HOME\s0/.consolerc
per-user configuration file
.PD
.SH BUGS
It is possible to create a loop of console connections, with ugly results.
Never run
.B console
from within a console connection (unless you set each
escape sequence differently).
.PP
The \-i output can produce more than the stated number of fields of
information if the user-provided information has embedded colons.
.PP
I'm sure there are more, I just don't know where they are.
Please let me know if you find any.
.SH AUTHORS
Thomas A. Fine, Ohio State Computer Science
.br
Kevin Braunsdorf, Purdue University Computing Center
.br
Bryan Stansell, conserver.com
.SH "SEE ALSO"
.BR conserver.cf (5),
.BR conserver.passwd (5),
.BR conserver (8)