Manpage of CONSOLE


Section: User Commands (1)
Updated: Local
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console - console server client program  


console [-aAfFGsS] [-7Dv] [-M mach] [-p port] [-e esc] [-l user] console
console [-hPrRuVwx] [-7Dv] [-M mach] [-p port] [-b message]
console [-qQ] [-7Dv] [-M mach] [-p port]  


Console is used to manipulate console terminals remotely or to poll running conserver(8) daemons for status information.

In the first form above, 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. Only as much of the console name as is required to identify it uniquely to the server is required.

For non-interactive options, console outputs only the requested information and exits.

Console knows only of a primary conserver host (see the -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 console is invoked with the `-r' option). Console then opens connections to the appropriate server(s). It is not necessary for the user of console to know which server manages which consoles, as long as console knows a valid primary server and all available consoles are listed in the primary server's configuration file.  


Options may be given as separate arguments (e.g., -v -w) or clustered (e.g., -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.

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.
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.
Broadcast a message to all users connected to the console server.
Enable debugging output.
Set the initial two-character escape sequence to those represented by esc. Any of the forms output by cat(1)'s -v option are accepted. The default value is ``^Ec''.
Same as -a except it will force any existing connection into spy mode.
Request a raw connection to the group control virtual console; this is only useful for learning the protocol used by the interactive sequence.
Display a brief help message.
Display information in a machine-parseable format (see below for the details).
Set the login name used for authentication to user. By default, 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.
The console client program polls mach as the primary server, rather than the default set at compile time (typically ``console''). The default mach may be changed at compile time using the --with-master option.
Set the port to connect to. This may be either a port number or a service name. The default port may be changed at compile time using the --with-port option.
Display the pid of the master daemon process on each server.
The 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 file; in that case, just press <return>.
Same as -q but just acts on the primary server.
Display daemon versions. The console client connects to each server to request its version information.
Same as -r but just acts on the primary server.
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.
Show a list of all consoles with status (`up' or `down') and attached users (user@host if attached read-write, `<spies>' if only users in spy mode, or `<none>').
Be more verbose when building the connection(s). Use this option in combination with any of `show' options (below) for added benefit.
Output the version and settings of the console client program and then exit.
Show a list of all who are currently connected to consoles, including the hostnames where the 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 conserver.
Show a list of consoles and devices.

The -A, -F, or -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 `^Ecr' were typed).

The -i option outputs information regarding each console in ten colon-separated fields.

The name of the console.
The hostname, pid, and socket number of the child process managing the console.
The type of console. Values will be a `/' for a local device, `|' for a command, or `!' for a remote port.
The details regarding the console. The values here (all comma seperated) depend on the type of the console. Local devices will have values of the device file, baud rate, 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, and file descriptor for the socket connection.
The details of each user connected to the console. The details for each user are an `@' seperated list of `w', `r', or `s' (for read-write, read-only, or suspended), username, hostname the user is on, and the user's idle time. Each user bundle is seperated by commas.
The state of the console. Values with either be ``up'' or ``down''.
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.
The details regarding the logging for the console. The comma seperated 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.
The default break sequence used for the console.
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''.


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 conserver(8) man page for more information.) Commands are:

attach read-write if nobody already is
send broadcast message to all users on this console
toggle flow control (don't do this)
down the current console
change the escape sequence to the next two characters
forcibly attach read-write
group info
toggle logging on/off
list the break sequences available
send the break sequence associated with this console
send the specific break sequence
close (if open) and reopen the line (to clear errors (silo overflows)) and the log file
replay the last 60 lines of output
replay the last 20 lines of output
switch to spy mode (read-only)
show status of hosts/users in this group
show the version of the group server
who is using this console
examine this group's devices and modes
suspend this connection
display list of commands
^M (return)
continue, ignore the escape sequence
^R (ctrl-R)
replay the last line only
send character having octal code ooo (must specify three octal digits)

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 full two-way attachment. To send the escape sequence through the connection one must redefine the outer escape sequence, or use ^Ec\ooo to send the first escape character before typing the second character directly.

In the -u output, the login ``<none>'' indicates no one is viewing that console, and the login ``<spies>'' indicates that no one has a full two-way attachment. When no one is attached to a console its output is cloned to the stdout of the server process if conserver was started with the -u option.  


console -u
Outputs something like:

dumb              up    <none>

expert           up    ksb@mentor

tyro             up    <spies>

mentor           up    <none>

sage             up    fine@cis
The <none> indicates no one is viewing dumb or mentor, the <spies> indicates only read-only connections exist for tyro, and other login@host entries indicate users attached read-write to sage and expert.
console -w
Outputs something like:

ksb@extra         attach  2days expert

file@cis         attach  21:46 sage

dmr@alice        spy      0:04 tyro
The third column is the idle time of the user. Either hours:minutes or number of days is displayed.
console -e ``^[1'' lv426
Requests a connection to the host ``lv426'' with the escape characters set to ``escape one''.


All client/server traffic (including root and user passwords) is passed ``in the clear''. Extreme care should be taken to insure no one is ``snooping'' this private data. One day the traffic will be encrypted.

It is possible to create a loop of console connections, with ugly results. Never run console from within a console connection (unless you set each escape sequence differently).

The -G option doesn't help to explain how connections get built.  


Thomas A. Fine, Ohio State Computer Science
Kevin Braunsdorf, Purdue University Computing Center
Bryan Stansell,  

SEE ALSO, conserver.passwd(5), conserver(8)




This document was created by man2html, using the manual pages.
Time: 06:55:22 GMT, April 25, 2024