SH-TK(1)SH-TK(1)NAME
tk, chan, send, recv, alt - loadable tk module for sh.
SYNOPSIS
load tk
chan name...
send chan value
tk window title [ args... ]
tk winctl winid cmd
tk wintitle winid title
tk namechan chan [ name ]
tk del name
tk winid tkcmd
${tk window title [ args... ] }
${tk onscreen winid [ how ] }
${tk winid tkcmd }
${recv chan }
${alt chan ... }
DESCRIPTION
Tk is a loadable module for sh(1) that provides access to Inferno Tk
graphics and string channels. Most of the builtin commands that it
defines map closely to primitives within wmlib(2) and tk(2). Unless
otherwise stated, if a command requires a winid argument, if no window
with that id is found, a bad win exception is raised. Similarly, a ref‐
erence to an unknown channel name will raise a bad chan exception.
There is no requirement that this module be used in a windowing con‐
text: although window creation will fail if there is no context, the
channel communication primitives will work regardless.
chan For each name in turn, chan creates a new channel called name
within the tk module. Name henceforth represents a Limbo
chan of string and can be used to send string values between
sh processes running in parallel. A chan is also used to
receive events arriving from the window manager. It is ille‐
gal to create a channel whose name consists entirely of
numeric digits.
send Send sends its argument value down the channel chan, blocking
until a corresponding receive operation takes place on the
channel.
tk window Tk window creates a new top-level window with the text of
title in the titlebar at the top. Each window created by the
tk module is assigned a unique numeric id. This id is printed
by this command; to get access to the value of the winid in a
script, use ${tk window}. All the remaining arguments are
joined together by spaces and passed as the tk options for
the window. When a window is created, a corresponding chan‐
nel of the same name is created. Events from the window man‐
ager arrive on this channel, and should be responded to
appropriately using tk winctl.
tk onscreen
Tk onscreen must be called to make window winid visible for
the first time, the same as onscreen in tkclient(2). How is
the same as for that call - if given, it must be one of
place, onscreen or exact.
tk winctl Tk winctl is used to communicate requests to the window man‐
ager. (see winctl() in wmlib(2)). If an event arriving on a
window's channel is passed to tk winctl, a suitable default
action will take place. The set of possible actions include:
exit A request to close the window.
size A request to resize the window.
task A request to miniaturise the window.
move A request to move the window.
tk wintitle
Tk wintitle changes the title of the window winid to title.
tk del Tk del deletes a channel or a window. If name is the winid of
an existing window, then both the window and its associated
channel are destroyed. A del of a non-existent channel or
window is ignored.
tk namechan
Tk namechan invokes the Tk module's namechan() function to
give a tk name to a channel within the tk module. If name is
omitted, then the tk name given will be the same as chan.
tk winid If winid is the id of an existing window, the rest of the
arguments joined together by spaces and sent as a tk command
to be interpreted in that window. If the shell is in interac‐
tive mode, then the string returned by tk will be printed.
The exit status of tk is false if the string returned by tk
begins with a bang (!) character.
${tk window}
Tk window is the same as its command counterpart, except that
it yields the winid of the newly created window rather than
printing it.
${tk winid}
This command is the same as its command counterpart, except
that it yields the return value from the Tk command as its
result.
${recv} Recv receives a string value from chan and yields that value.
It will block until a corresponding send operation takes
place on the channel.
${alt} Alt waits until a value is available on any of the named
chans. It yields a list containing two elements, the name of
the channel from which the value was received, and the actual
value received.
EXAMPLE
The following code creates a window and allows normal window manager
operations on it. Another shell in a new process group is created in
order to prevent the shell window from disappearing when the tk window
is deleted.
sh
load std tk
pctl newpgrp
wid=${tk window 'My window'}
tk onscreen $wid
tk $wid update
while {} {tk winctl $wid ${recv $wid}} &
SOURCE
/appl/cmd/sh/tk.b
SEE ALSOsh(1), sh-std(1), sh-expr(1), tkcmd(1), tk(2), tkclient(2), wmlib(2),
``The Tk Reference Manual''
SH-TK(1)
