term% cat index.txt MUX(9.1) MUX(9.1)
NAME
mux, ismux, invert - layer multiplexer for jerq
SYNOPSIS
mux [ -l commands ]
mux exit
mux cd directory
ismux [ - ]
invert
DESCRIPTION
Mux manages asynchronous windows, or layers, on the jerq terminal.
Upon invocation, it loads the jerq with a program (default
/usr/jerq/lib/muxterm, settable by the environment variable MUXTERM)
that is the primary user interface. Option -l also creates a layer and
invokes the shell to run commands in it. (See windows(9.1)).
The command `mux exit' leaves mux, destroying all layers; `mux cd'
changes the directory of mux, and hence of layers later created, but
not of the current layers.
Each layer is essentially a separate terminal. Characters typed into
the layer are sent to the standard input of a Unix process bound to the
layer, and characters written on the standard output of that process
appear in the layer. When a layer is created, a separate shell (the
value of the SHELL environment variable, or sh by default) is estab‐
lished, and bound to the layer.
Layers are created, deleted, and rearranged using the mouse. Depress‐
ing mouse button 3 activates a menu of layer operations. Releasing
button 3 then selects an operation. At this point, a gunsight cursor
indicates that an operation is pending. Hitting button 3 again acti‐
vates the operation on the layer pointed to by the cursor. The New op‐
eration, to create a layer, requires a rectangle to be swept out,
across any diagonal, while button 3 is depressed. A box outline cursor
indicates that a rectangle is to be created. The Reshape operation, to
change the size and location of a layer on the screen, requires first
that a layer be indicated (gunsight cursor) and a new rectangle be
swept out (box cursor). The other operations are self-explanatory.
In a non-current layer, button 1 is a shorthand for Current and Top,
which pulls a layer to the front of the screen and makes it the current
layer for keyboard and mouse input. Non-current layers are indicated
by a light border.
There is a point in each layer, called the `Unix point', where the next
character from Unix will be inserted. The Unix point advances whenever
characters are received from Unix, but not when echoing typed charac‐
ters. When a newline is typed after the Unix point, characters between
the Unix point and the newline, inclusive, are sent to Unix and the
Unix point advanced to after the newline. This means that shell
prompts and other output will be inserted before characters that have
been typed ahead. No other characters are sent to Unix (but see the
discussion of raw mode below). Therefore partially typed lines or text
anywhere before the Unix point may be edited.
The default terminal program allows any text on the screen to be
edited, much as in jim(9.1). Text may be selected by sweeping it with
button 1 depressed. Typed characters replace selected text.
All layers share a common `snarf buffer' (distinct from jim's). The
cut operation on button 2 deletes selected text and puts it in the buf‐
fer; snarf copies selected text to the buffer; paste replaces selected
text (which may be null) from the buffer; and send copies the snarf
buffer to after the Unix point.
Normally the terminal doesn't scroll as text is received, but a button
2 menu item selects scrolling. A scroll bar indicates what portion of
all the text stored for a layer is on the screen. (It measures charac‐
ters, not lines.) Releasing button 1 in the scroll bar brings the line
at the top of the screen to the cursor; releasing button 3 takes the
line at the cursor to the top of the screen. Button 2, treating the
scroll bar as a ruler, brings the indicated point in the whole stored
text to the top of the screen.
The NUM LOCK key advances a half page.
Ismux reports on its standard error whether its standard output is a
mux layer, and also generates the appropriate exit status. With the
optional argument, no message is produced.
Invert reverses the sense of video, from black on white to white on
black, or vice versa.
Independent user-level programs can be loaded into layers, see
32ld(9.1). SHIFT-SETUP freezes mux and complements the video of the
layer of the running user-level terminal process. Hitting button 2 in
this state will attempt to kill the process; 1 or 3 will leave it run‐
ning.
In raw mode or no-echo mode (see ttyld(4)) the Unix point advances with
each character typed after it.
FILES
/usr/jerq/lib/muxterm terminal program
/tmp/.mux* temporary file used by -l option
SEE ALSO
32ld(9.1), jim(9.1), jx(9.1), term(9.1)
DIAGNOSTICS
Mux refuses to create a layer when there is not enough memory. Space
can be recovered by deleting a layer.
Error messages from mux are written directly to the layer which caused
them. They are usually meaningful only to system administrators, and
indicate system difficulties.
BUGS
Reshape only works properly for processes that arrange to see if they
have been reshaped, although most programs make this arrangement.
The behavior of raw mode prohibits editing partially typed lines when
running cu(1).
MUX(9.1)