Ubuntu Manpage: kibitz - allow two people to interact with one shell

NAME

       kibitz - allow two people to interact with one shell

SYNOPSIS

       kibitz [ kibitz-args ] user [ program program-args...  ]
       kibitz [ kibitz-args ] user@host [ program program-args...  ]

INTRODUCTION

       kibitz allows two (or more) people to interact with one shell (or any arbitrary program).  Uses include:

              •   A novice user can ask an expert user for help.  Using kibitz, the expert can see what the user
                  is doing, and offer advice or show how to do it right.

              •   By running kibitz and then starting a full-screen editor, people may carry out a conversation,
                  retaining the ability to scroll backwards, save the entire conversation, or even edit it while
                  in progress.

              •   People  can  team  up on games, document editing, or other cooperative tasks where each person
                  has strengths and weaknesses that complement one another.

USAGE

       To start kibitz, user1 runs kibitz with the argument of the user to kibitz.  For example:

            kibitz user2

       kibitz starts a new shell (or another program, if given on the command line), while  prompting  user2  to
       run  kibitz.   If  user2  runs  kibitz  as directed, the keystrokes of both users become the input of the
       shell.  Similarly, both users receive the output from the shell.

       To terminate kibitz it suffices to terminate the shell itself.  For example, if either user types ^D (and
       the shell accepts this to be EOF), the shell terminates followed by kibitz.

       Normally, all characters are passed uninterpreted.  However, if  the  escape  character  (described  when
       kibitz  starts) is issued, the user may talk directly to the kibitz interpreter.  Any Expect(1) or Tcl(3)
       commands may be given.  Also, job control may be used while in the interpreter, to, for example,  suspend
       or restart kibitz.

       Various  processes  can provide various effects.  For example, you can emulate a two-way write(1) session
       with the command:

            kibitz user2 sleep 1000000

ARGUMENTS

       kibitz takes arguments, these should also be separated by whitespace.

       The -noproc flag runs kibitz with no process underneath.  Characters are  passed  to  the  other  kibitz.
       This  is  particularly  useful  for  connecting  multiple  interactive processes together.  In this mode,
       characters are not echoed back to the typist.

       -noescape disables the escape character.

       -escape char sets the escape character.  The default escape character is ^].

       -silent turns off informational messages describing what kibitz is doing to initiate a connection.

       -tty ttyname defines the tty to which the invitation should be sent.

       If you start kibitz to user2 on a remote computer, kibitz performs a rlogin to the remote  computer  with
       your  current username. The flag -proxy username causes rlogin to use username for the remote login (e.g.
       if your account on the remote computer has a different username). If the -proxy flag is not given, kibitz
       tries to determine your current username by (in that order) inspecting the environment variables USER and
       LOGNAME, then by using the commands whoami and logname.

       The arguments -noescape and -escape can also be given by user2 when prompted to run kibitz.

MORE THAN TWO USERS

       The current implementation of kibitz explicitly understands only two users, however,  it  is  nonetheless
       possible  to have a three (or more) -way kibitz, by kibitzing another kibitz.  For example, the following
       command runs kibitz with the current user, user2, and user3:

            % kibitz user2 kibitz user3

       Additional users may be added by simply appending more "kibitz user" commands.

       The xkibitz script is similar to kibitz but supports the ability to add additional users (and drop  them)
       dynamically.

CAVEATS

kibitz assumes the 2nd user has the same terminal type and size as the 1st user. If this assumption is
incorrect, graphical programs may display oddly.

kibitz handles character graphics, but cannot handle bitmapped graphics. Thus,

% xterm -e kibitz will work
% kibitz xterm will not work

However, you can get the effect of the latter command by using xkibitz (see SEE ALSO below). kibitz uses
the same permissions as used by rlogin, rsh, etc. Thus, you can only kibitz to users at hosts for which
you can rlogin. Similarly, kibitz will prompt for a password on the remote host if rlogin would.

If you kibitz to users at remote hosts, kibitz needs to distinguish your prompt from other things that
may precede it during login. (Ideally, the end of it is preferred but any part should suffice.) If you
have an unusual prompt, set the environment variable EXPECT_PROMPT to an egrep(1)-style regular
expression. Brackets should be preceded with one backslash in ranges, and three backslashes for literal
brackets. The default prompt r.e. is "($|%|#) ".

kibitz requires the kibitz program on both hosts. kibitz requires expect(1).

By comparison, the xkibitz script uses the X authorization mechanism for inter-host communication so it
does not need to login, recognize your prompt, or require kibitz on the remote host. It does however
need permission to access the other X servers.

BUGS

       An  early version of Sun's tmpfs had a bug in it that causes kibitz to blow up.  If kibitz reports "error
       flushing ...: Is a directory" ask Sun for patch #100174.

       If your Expect is not compiled with multiple-process support (i.e., you do not have a working  select  or
       poll), you will not be able to run kibitz.

ENVIRONMENT

       The  environment  variable SHELL is used to determine the shell to start, if no other program is given on
       the command line.

       If the environment variable EXPECT_PROMPT exists, it is taken as a regular expression which  matches  the
       end of your login prompt (but does not otherwise occur while logging in). See also CAVEATS above.

       If  the  environment  variables  USER or LOGNAME are defined, they are used to determine the current user
       name for a kibitz to a remote computer. See description of the -proxy option in ARGUMENTS above.

AUTHOR

       Don Libes, National Institute of Standards and Technology

       kibitz is in the public domain.  NIST and I would appreciate credit if this program or parts  of  it  are
       used.

                                                 19 October 1994                                       KIBITZ(1)