Provided by: clusterssh_4.02.02+20140117+git58bd88a0-1_all bug


       cssh, crsh, ctel, ccon - Cluster administration tool


       cssh [options] [[user@]<server>[:port]|<tag>] [...]
       crsh [options] [[user@]<server>[:port]|<tag>] [...]
       ctel [options] [<server>[:port]|<tag>] [...]
       ccon [options] [[user@]<server>[:port]|<tag>] [...]


       The command opens an administration console and an xterm to all specified hosts.  Any text
       typed into the administration console is replicated to all windows.  All windows may also
       be typed into directly.

       This tool is intended for (but not limited to) cluster administration where the same
       configuration or commands must be run on each node within the cluster.  Performing these
       commands all at once via this tool ensures all nodes are kept in sync.

       Connections are opened via ssh so a correctly installed and configured ssh installation is
       required.  If, however, the program is called by "crsh" then the rsh protocol is used (and
       the communications channel is insecure), or by "ctel" then telnet is used, or by "ccon"
       then console is used.

       Extra caution should be taken when editing system files such as /etc/inet/hosts as lines
       may not necessarily be in the same order.  Assuming line 5 is the same across all servers
       and modifying that is dangerous.  Better to search for the specific line to be changed and
       double-check before changes are committed.

   Further Notes
       Please also see "KNOWN BUGS".

       ·   The dotted line on any sub-menu is a tear-off, i.e. click on it and the sub-menu is
           turned into its own window.

       ·   Unchecking a hostname on the Hosts sub-menu will unplug the host from the cluster
           control window, so any text typed into the console is not sent to that host.  Re-
           selecting it will plug it back in.

       ·   If your window manager menu bars are obscured by terminal windows see the
           "screen_reserve_XXXXX" options in the $HOME/.clusterssh/config file (see "FILES").

       ·   If the terminals overlap too much see the "terminal_reserve_XXXXX" options in the
           $HOME/.clusterssh/config file (see "FILES").

       ·   If the code is called as crsh instead of cssh (i.e. a symlink called crsh points to
           the cssh file or the file is renamed) rsh is used as the communications protocol
           instead of ssh.

       ·   If the code is called as ctel instead of cssh (i.e. a symlink called ctel points to
           the cssh file or the file is renamed) telnet is used as the communications protocol
           instead of ssh.

       ·   If the code is called as ccon instead of cssh (i.e. a symlink called ccon points to
           the cssh file or the file is renamed) console is used as the communications protocol
           instead of ssh.

       ·   When using cssh on a large number of systems to connect back to a single system (e.g.
           you issue a command to the cluster to scp a file from a given location) and when these
           connections require authentication (i.e. you are going to authenticate with a
           password), the sshd daemon at that location may refuse connects after the number
           specified by MaxStartups in sshd_config is exceeded.  (If this value is not set, it
           defaults to 10.)  This is expected behavior; sshd uses this mechanism to prevent DoS
           attacks from unauthenticated sources.  Please tune sshd_config and reload the SSH
           daemon, or consider using the ~/.ssh/authorized_keys mechanism for authentication if
           you encounter this problem.

       ·   If client windows fail to open, try running:

           "cssh -e {single host name}"

           This will test the mechanisms used to open windows to hosts.  This could be due to
           either the "-xrm" terminal option which enables "AllowSendEvents" (some terminal do
           not require this option, other terminals have another method for enabling it - see
           your terminal documention) or the "ConnectTimeout" ssh option (see the configuration
           option "-o" or file "$HOME/.clusterssh/config" below to resolve this).


       Some of these options may also be defined within the configuration file.  Default options
       are shown as appropriate.

       --action,-a '<command>'
           Run the command in each session, i.e. "-a 'vi /etc/hosts'" to drop straight into a vi
           session.  NOTE: not all communications methods support this (ssh and rsh should,
           telnet and console will not).

       --autoclose,-A <seconds>
           Number of seconds to wait before closing finished terminal windows.

           Enable|Disable automatically quiting after the last client window has closed
           (overriding the config file)

       --cluster-file,-c <file>
           Use supplied file as additional cluster file (see also "FILES")

       --config-file,-C <file>
           Use supplied file as additional configuration file (see also "FILES")

       -d  DEPRECATED.  See '--debug'.

       -D  DEPRECATED.  See '--debug'.

       --debug [number].
           Enable debugging.  Either a level can be provided or the option can be repeated
           multiple times.  Maximum level is 4.

       --evaluate,-e [user@]<hostname>[:port]
           Display and evaluate the terminal and connection arguments so display any potential
           errors.  The <hostname> is required to aid the evaluation.

       --font,-f "5x8"
           Specify the font to use in the terminal windows. Use standard X font notation.

           Show basic help text, and exit

       --list, -L
           List available cluster tags.

           Show full help test (the man page), and exit

       --master,-M <master>
           The console client program polls master as the primary server, rather than the default
           set at compile time (typically ``console'').

       --options,-o "-x -o ConnectTimeout=10" - for ssh connections
       --options,-o ""                        - for rsh connections
           Specify arguments to be passed to ssh or rsh when making the connection.

           NOTE: any "generic" change to the method (i.e. specifying the ssh port to use) should
           be done in the medium's own config file (see "ssh_config" and $HOME/.ssh/config).

           Output the current configuration in the same format used by the
           $HOME/.clusterssh/config file.

       --port,-p <port>
           Specify an alternate port for connections.

           IN BETA: Show history within console window.  This code is still being worked upon,
           but may help some users.

       --tag-file,-r <file>
           Use supplied file as additional tag file (see also "FILES")

       --term-args,-t ""
           Specify arguments to be passed to terminals being used

           Enable|Disable window tiling (overriding the config file)

       --title,-T "CSSH"
           Specify the initial part of the title used in the console and client windows

           Connect to each host only once

           If a hostname resolves to multiple IP addresses, toggle whether or not to connect to
           all of them, or just the first one (see also config file entry)

       --username,-l $LOGNAME
           Specify the default username to use for connections (if different from the currently
           logged in user).  NOTE: will be overridden by <user>@<host>

           Show version information and exit


       The following arguments are support:

       [user@]<hostname>[:port] ...
           Open an xterm to the given hostname and connect to the administration console.  An
           optional port number can be used if sshd is not listening on standard port (e.g not
           listening on port 22) and ssh_config cannot be used.

       <tag> ...
           Open a series of xterms defined by <tag> in one of the suplimentary configuration
           files (see "FILES").

           Note: specifying a username on a cluster tag will override any usernames defined in
           the cluster


       The following key shortcuts are available within the console window, and all of them may
       be changed via the configuration files.

           Quit the program and close all connections and windows

           Open the 'Add Host(s) or Cluster(s)' dialogue box.  Mutiple host or cluster names can
           be entered, separated by spaces.

           Paste in the hostname part of the specific connection string to each client, minus any
           username or port, i.e.

           "scp /etc/hosts server:files/<Alt-n>.hosts"

           would replace the <Alt-n> with the client's name in each window

           Retile all the client windows


       Open up a session to 3 servers
           $ cssh server1 server2 server3

       Open up a session to a cluster of servers identified by the tag 'farm1' and give the
       controlling window a specific title, where the cluster is defined in one of the default
       configuration files
           $ cssh -T 'Web Farm Cluster 1' farm1

       Connect to different servers using different login names.  NOTE: this can also be achieved
       by setting up appropriate options in the .ssh/config file. Do not close cssh when last
       terminal exits.
           $ cssh -Q user1@server1 admin@server2

       Open up a cluster defined in a non-default configuration file
           $ cssh -c $HOME/cssh.config db_cluster

       Use telnet on port 2022 instead of ssh
           $ ctel -p 2022 server1 server2

       Use rsh instead of ssh
           $ crsh server1 server2

       Use console with master as the primary server instead of ssh
           $ ccon -M master server1 server2


       /etc/clusters, $HOME/.clusterssh/clusters
           These files contain a list of tags to server names mappings.  When any name is used on
           the command line it is checked to see if it is a tag.  If it is a tag, then the tag is
           replaced with the list of servers.  The formated is as follows:

           <tag> [user@]<server> [user@]<server> [...]


             # List of servers in live
             live admin1@server1 admin2@server2 server3 server4

           All comments (marked by a #) and blank lines are ignored.  Tags may be nested, but be
           aware of using recursive tags as they are not checked for.

           Extra cluster files may also be specified either as an option on the command line (see
           "cluster-file") or in the users $HOME/.clusterssh/config file (see
           "extra_cluster_file" configuration option).

           NOTE: the last tag read overwrites any pre-existing tag of that name

           NOTE: there is a special cluster tag called "default" - any tags or hosts included
           within this tag will be automatically opened if no other tags are specified on the
           command line.

       /etc/tags, $HOME/.clusterssh/tags
           Very similar to cluster files but the definition is reversed.  The format is:

           <host> <tag> [...]

           This allows one host to be specified as a member of a number of tags.  This format can
           be clearer than using clusters files.

           Extra tag files may be spcieid either an an option (see "tag-file") or within the
           users $HOME/.clusterssh/config file (see "extra_tag_file" configuration option).

           NOTE: All tags are added together

       /etc/csshrc & $HOME/.clusterssh/config
           This file contains configuration overrides - the defaults are as marked.  Default
           options are overwritten first by the global file, and then by the user file.

           NOTE: values for entries do not need to be quoted unless it is required for passing
           arguments, i.e.

             terminal_allow_send_events="-xrm '*.VT100.allowSendEvents:true'"

           should be written as

             terminal_allow_send_events=-xrm '*.VT100.allowSendEvents:true'

           auto_close = 5
               Close terminal window after this many seconds.  If set to 0 will instead wait on
               input from the user in each window before closing. Can be overridden by "-K" on
               the command line

           auto_quit = yes
               Automatically quit after the last client window closes.  Set to anything other
               than "yes" to disable.  Can be overridden by "-Q" on the command line.

           clusters = <blank>
               Define a number of cluster tags in addition to (or to replace) tags defined in the
               /etc/clusters file.  The format is:

                clusters = <tag1> <tag2> <tag3>
                <tag1> = host1 host2 host3
                <tag2> = user@host4 user@host5 host6
                <tag3> = <tag1> <tag2>

               As with the /etc/clusters file, be sure not to create recursivly nested tags.

           comms = ssh
               Sets the default communication method (initially taken from the name of program,
               but can be overridden here).

           console_position = <null>
               Set the initial position of the console - if empty then let the window manager
               decide.  Format is '+<x>+<y>', i.e. '+0+0' is top left hand corner of the screen,
               '+0-70' is bottom left hand side of screen (more or less).

           external_cluster_command = <null>
               Define the full path to an external command that can be used to resolve tags to
               host names.  This command can be written in any language.  The script must accept
               a list of tags to resolve and output a list of hosts on a single line.  Any tags
               that cannot be resolved should be returned unchanged.

               A non-0 exit code will be counted as an error, a warning will be printed and
               output ignored.

           extra_cluster_file = <null>
               Define an extra cluster file in the format of /etc/clusters.  Multiple files can
               be specified, seperated by commas.  Both ~ and $HOME are acceptable as a to
               reference the users home directory, i.e.

                extra_cluster_file = ~/clusters, $HOME/clus

               THIS OPTION IS DEPRECATED.  It has been left in so current systems continue to
               function as expected.

           key_addhost = Control-Shift-plus
               Default key sequence to open AddHost menu.  See below notes on shortcuts.

           key_clientname = Alt-n
               Default key sequence to send cssh client names to client.  See below notes on

           key_localname = Alt-l
               Default key sequence to send hostname of local server to client.  See below notes
               on shortcuts.

           key_paste = Control-v
               Default key sequence to paste text into the console window.  See below notes on

           key_quit = Control-q
               Default key sequence to quit the program (will terminate all open windows).  See
               below notes on shortcuts.

           key_retilehosts = Alt-r
               Default key sequence to retile host windows.  See below notes on shortcuts.

           key_username = Alt-u
               Default key sequence to send username to client.  See below notes on shortcuts.

           macro_servername = %s
           macro_hostname = %h
           macro_username = %u
           macro_newline = %n
           macro_version = %v
               Change the replacement macro used when either using a 'Send' menu item, or when
               pasting text into the main console.

           macros_enabled = yes
               Enable or disable macro replacement.  Note: this affects pasting into the main
               console,  items on the 'Send' menu and key_clientname, key_localname,
               key_servername and key_username.

           max_addhost_menu_cluster_items = 6
               Maximum number of entries in the 'Add Host' menu cluster list before scrollbars
               are used

           max_host_menu_items = 30
               Maximum number of hosts to put into the host menu before starting a new column

           menu_host_autotearoff = 0
           menu_send_autotearoff = 0
               When set to non-0 will automatically tear-off the host or send menu at program

           mouse_paste = Button-2 (middle mouse button)
               Default key sequence to paste text into the console window using the mouse.  See
               below notes on shortcuts.

           rsh = rsh
           ssh = ssh
           telnet = telnet
               Set the path to the specific binary to use for the communication method, else uses
               the first match found in $PATH

           rsh_args = <blank>
           ssh_args = "-x -o ConnectTimeout=10"
           telnet_args = <blank>
               Sets any arguments to be used with the communication method (defaults to ssh

               NOTE: The given defaults are based on OpenSSH, not commercial ssh software.

               NOTE: Any "generic" change to the method (i.e. specifying the ssh port to use)
               should be done in the medium's own config file (see "ssh_config" and

           screen_reserve_top = 0
           screen_reserve_bottom = 60
           screen_reserve_left = 0
           screen_reserve_right = 0
               Number of pixels from the screen side to reserve when calculating screen geometry
               for tiling.  Setting this to something like 50 will help keep cssh from
               positioning windows over your window manager's menu bar if it draws one at that
               side of the screen.

           rsh = /path/to/rsh
           ssh = /path/to/ssh
               Depending on the value of comms, set the path of the communication binary.

           terminal = /path/to/terminal
               Path to the x-windows terminal used for the client.

           terminal_args = <blank>
               Arguments to use when opening terminal windows.  Otherwise takes defaults from
               $HOME/.Xdefaults or $<$HOME/.Xresources> file.

           terminal_font = 6x13
               Font to use in the terminal windows.  Use standard X font notation.

           terminal_reserve_top = 5
           terminal_reserve_bottom = 0
           terminal_reserve_left = 5
           terminal_reserve_right = 0
               Number of pixels from the terminal side to reserve when calculating screen
               geometry for tiling.  Setting these will help keep cssh from positioning windows
               over your scroll and title bars or otherwise overlapping the windows too much.

           terminal_colorize = 1
               If set to 1 (the default), then "-bg" and "-fg" arguments will be added to the
               terminal invocation command-line.  The terminal will be colored in a pseudo-random
               way based on the host name; while the color of a terminal is not easily predicted,
               it will always be the same color for a given host name.  After a while, you will
               recognize hosts by their characteristic terminal color.

           terminal_bg_style = dark
               If set to dark, the the terminal background will be set to black and the
               foreground to the pseudo-random color.  If set to light, then the foreground will
               be black and the background the pseudo-random color.  If terminal_colorize is
               zero, then this option has no effect.

           terminal_size = 80x24
               Initial size of terminals to use (note: the number of lines (24) will be decreased
               when resizing terminals for tiling, not the number of characters (80))

           terminal_title_opt = -T
               Option used with "terminal" to set the title of the window

           terminal_allow_send_events = -xrm '*.VT100.allowSendEvents:true'
               Option required by the terminal to allow XSendEvents to be received

           title = cssh
               Title of windows to use for both the console and terminals.

           unmap_on_redraw = no
               Tell Tk to use the UnmapWindow request before redrawing terminal windows.  This
               defaults to "no" as it causes some problems with the FVWM window manager.  If you
               are experiencing problems with redraws, you can set it to "yes" to allow the
               window to be unmapped before it is repositioned.

           use_all_a_records = no
               If a hostname resolves to multiple IP addresses, set to "yes" to connect to all of
               them, not just the first one found.

           use_hotkeys = yes
               Setting to anything other than "yes" will disable all hotkeys.

           user = $LOGNAME
               Sets the default user for running commands on clients.

           window_tiling = yes
               Perform window tiling (set to "no" to disable)

           window_tiling_direction = right
               Direction to tile windows, where "right" means starting top left and moving right
               and then down, and anything else means starting bottom right and moving left and
               then up

           NOTE: The key shortcut modifiers must be in the form "Control", "Alt", or "Shift",
           i.e. with the first letter capitalised and the rest lower case.  Keys may also be
           disabled individually by setting to the word "null".

           This (optional) file contains items to populate the send menu.  The default entry
           could be written as:

               <menu title="Use Macros">
               <menu title="Remote Hostname">
               <menu title="Local Hostname">
               <menu title="Username">
               <menu title="Test Text">
                   <command>echo "ClusterSSH Version: %v%n</command>

           Submenus can also be specified as follows:

               <menu title="Default Entries">
                 <menu title="Hostname">


           There is currently no strict format checking of this file.
           The format of the file may change in the future
           If the file exists the default entry (Hostname) is not added

           The following replacement macros are available (note: these can be changed in the
           configuration file):

           %s  Hostname part of the specific connection string to each client, minus any username
               or port

           %u  Username part of the connection string to each client

           %h  Hostname of server where cssh is being run from

           %n  <RETURN> code

           NOTE: requires XML::Simple to be installed


       1.  Catering for IPv6 addresses is minimal.  This is due to a conflict between IPv6
           addresses and port numbers within the same server definition since they both use the
           same seperator, i.e. is the following just an IPv6 address, or an address + port
           number of 2323?


           Exactly - I cannot tell either.  the IPv6 address without a port is assumed in those
           cases where it cannot be determined and a warning is issued.

           Possible work arounds include:

           a.  Use square brackets around the IPv6 address, i.e.
                   [2001:db8::1428]:2323 or
                   [2001:db8::1428:2323] as appropriate so there is no ambiguity

           b.  Use the full IPv6 address if also using a port number - the 8th colon is assumed
               to be the port seperator.

           c.  Define the IPv6 address in your /etc/hosts file, DNS or other name service lookup
               mechanism and use the hostname instead of the address.

       2.  Swapping virtual desktops can a redraw of all the terminal windows.  This is due to a
           lack of distinction within Tk between switching desktops and minimising/maximising
           windows.  Until Tk can tell the difference between the two events, there is no fix
           (apart from rewriting everything directly in X)

       Anyone with any good ideas to fix the above bugs is more than welcome to get in touch
       and/or provide a patch.


       · If you have issues running cssh, first try:

         "cssh -e [user@]<hostname>[:port]"

         This performs two tests to confirm cssh is able to work properly with the settings
         provided within the $HOME/.clusterssh/config file (or internal defaults).

                 1. test the terminal window works with the options provided

                 2. test ssh works to a host with the configured arguments

         Configuration options to watch for in ssh are

                 - Doesnt understand "-o ConnectTimeout=10" - remove the option
                   in the F<$HOME/.clusterssh/config> file

                 - OpenSSH-3.8 using untrusted ssh tunnels - use "-Y" instead of "-X"
                   or use "ForwardX11Trusted yes' in ssh_config (if you change the
                   default ssh options from -x to -X)

       · If you require support, please run the following commands and post it on the web site in
         the support/problems forum:

         "perl -V"

         "perl -MTk -e 'print $Tk::VERSION,$/'"

         "perl -MX11::Protocol -e 'print $X11::Protocol::VERSION,$/'"

         "cat /etc/csshrc $HOME/.clusterssh/config"

       · Use the debug switches (-d, -D, or -dD) will turn on debugging output.  However, please
         only use this option with one host at a time, i.e. "cssh -d <host>" due to the amount of
         output produced (in both main and child windows).


       <>, "ssh", Tk::overview, X11::Protocol, "perl"


       A web site for comments, requests, bug reports and bug fixes/patches is available at


       Duncan Ferguson, "<duncan_j_ferguson at>"


       Copyright 1999-2010 Duncan Ferguson.

       This program is free software; you can redistribute it and/or modify it under the terms of
       either: the GNU General Public License as published by the Free Software Foundation; or
       the Artistic License.

       See for more information.