NAME
xkibitz - allow multiple people to interact in an xterm
SYNOPSIS
xkibitz [ xkibitz-args ] [ program program-args... ]
INTRODUCTION
xkibitz allows users in separate xterms to share one shell (or any
program that runs in an xterm). Uses include:
· A novice user can ask an expert user for help. Using
xkibitz, the expert can see what the user is doing, and
offer advice or show how to do it right.
· By running xkibitz 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.
· If you want to have a large number of people do an on-line
code walk-through, you can sit two in front of each
workstation, and then connect them all together while you
everyone looks at code together in the editor.
USAGE
To start xkibitz, one user (the master) runs xkibitz with no arguments.
xkibitz starts a new shell (or another program, if given on the command
line). The user can interact normally with the shell, or upon entering
an escape (described when xkibitz starts) can add users to the
interaction.
To add users, enter "+ display" where display is the X display name.
If there is no ":X.Y" in the display name, ":0.0" is assumed. The
master user must have permission to access each display. Each display
is assigned a tag - a small integer which can be used to reference the
display.
To show the current tags and displays, enter "=".
To drop a display, enter "- tag" where tag is the display’s tag
according to the "=" command.
To return to the shared shell, enter "return". Then the keystrokes of
all users become the input of the shell. Similarly, all users receive
the output from the shell.
To terminate xkibitz it suffices to terminate the shell itself. For
example, if any user types ^D (and the shell accepts this to be EOF),
the shell terminates followed by xkibitz.
Normally, all characters are passed uninterpreted. However, in the
escape dialogue the user talks directly to the xkibitz interpreter.
Any Expect(1) or Tcl(3) commands may also be given. Also, job control
may be used while in the interpreter, to, for example, suspend or
restart xkibitz.
Various processes can produce various effects. For example, you can
emulate a multi-way write(1) session with the command:
xkibitz sleep 1000000
ARGUMENTS
xkibitz understands a few special arguments which should appear before
the program name (if given). Each argument should be separated by
whitespace. If the arguments themselves takes arguments, these should
also be separated by whitespace.
-escape sets the escape character. The default escape character is ^].
-display adds a display much like the "+" command. Multiple -display
flags can be given. For example, to start up xkibitz with three
additional displays:
xkibitz -display mercury -display fox -display dragon:1.0
CAVEATS
Due to limitations in both X and UNIX, resize propagation is weak.
When the master user resizes the xterm, all the other xterms are
logically resized. Unfortunately, xkibitz cannot force the physical
xterm size to correspond with the logical xterm sizes.
The other users are free to resize their xterm but their sizes are not
propagated. The master can check the logical sizes with the "="
command.
Deducing the window size is a non-portable operation. The code is
known to work for recent versions of SunOS, AIX, Unicos, and HPUX.
Send back mods if you add support for anything else.
ENVIRONMENT
The environment variable SHELL is used to determine and start a shell,
if no other program is given on the command line.
If the environment variable DISPLAY is defined, its value is used for
the display name of the xkibitz master (the display with tag number 0).
Otherwise this name remains empty.
Additional arguments may be passed to new xterms through the
environment variable XKIBITZ_XTERM_ARGS. For example, to create xterms
with a scrollbar and a green pointer cursor:
XKIBITZ_XTERM_ARGS="-sb -ms green"
export XKIBITZ_XTERM_ARGS
(this is for the Bourne shell - use whatever syntax is appropriate for
your favorite shell). Any option can be given that is valid for the
xterm command, with the exception of -display, -geometry and -S as
those are set by xkibitz.
SEE ALSO
Tcl(3), libexpect(3) kibitz(1)
"Exploring Expect: A Tcl-Based Toolkit for Automating Interactive
Programs" by Don Libes, O’Reilly and Associates, January 1995.
"kibitz - Connecting Multiple Interactive Programs Together", by Don
Libes, Software - Practice & Experience, John Wiley & Sons, West
Sussex, England, Vol. 23, No. 5, May, 1993.
AUTHOR
Don Libes, National Institute of Standards and Technology
06 October 1994