term% cat index.txt RIO(4) Kernel Interfaces Manual RIO(4)
NAME
rio - window system files
SYNOPSIS
rio [ -i 'cmd' ] [ -s ] [ -f font ]
DESCRIPTION
The window system rio serves a variety of files for reading, writing,
and controlling windows. Some of them are virtual versions of system
files for dealing with the display, keyboard, and mouse; others control
operations of the window system itself. Rio posts its service in the
/srv directory, using a name constructed from a catenation of the user
ID and a process id; the environment variable $wsys is set to this ser‐
vice name within processes running under the control of each invocation
of rio. Similarly, rio posts a named pipe to access the window cre‐
ation features (see window in rio(1)) from outside its name space; this
is named in $wctl.
A mount (see bind(1)) of $wsys causes rio to create a new window; the
attach specifier in the mount gives the coordinates of the created win‐
dow. The syntax of the specifier is the same as the arguments to win‐
dow (see rio(1)). By default, the window is sized and placed automati‐
cally. It is always necessary, however, to provide the process id of
the process to whom to deliver notes generated by DEL characters and
hangups in that window. That pid is specified by including the string
-pid pid in the attach specifier. (See the Examples section q.v.)
When a window is created either by the window command (see rio(1)) or
by using the menu supplied by rio, this server is mounted on /mnt/wsys
and also /dev; the files mentioned here appear in both those directo‐
ries.
Some of these files supply virtual versions of services available from
the underlying environment, in particular the character terminal files
cons(3), and the mouse files mouse(3) and cursor, each specific to the
window. Note that the draw(3) device multiplexes itself; rio places
windows but does not mediate programs' access to the display device.
Other files are unique to rio.
cons is a virtual version of the standard terminal file cons(3). Rio
supplies extra editing features and a scroll bar (see rio(1)).
consctl
controls interpretation of keyboard input. Writing strings to
it sets these modes: rawon turns on raw mode; rawoff turns off
raw mode; holdon turns on hold mode; holdoff turns off hold
mode. Closing the file makes the window revert to default state
(raw off, hold off).
cursor Like mouse (q.v.), a multiplexed version of the underlying de‐
vice file, in this case representing the appearance of the mouse
cursor when the mouse is within the corresponding window.
label initially contains a string with the process ID of the lead
process in the window and the command being executed there. It
may be written and is used as a tag when the window is hidden.
mouse is a virtual version of the standard mouse file (see mouse(3)).
Opening it turns off scrolling, editing, and rio-supplied menus
in the associated window. In a standard mouse message, the
first character is m, but rio will send an otherwise normal mes‐
sage with the first character r if the corresponding window has
been resized. The application must then call getwindow (see
graphics(2)) to re-establish its state in the newly moved or
changed window. Reading the mouse file blocks until the mouse
moves or a button changes. Mouse movements or button changes
are invisible when the mouse cursor is located outside the win‐
dow, except that if the mouse leaves the window while a button
is pressed, it will continue receiving mouse data until the but‐
ton is released.
screen is a read-only file reporting the depth, coordinates, and raster
image corresponding to the entire underlying display, in the un‐
compressed format defined in image(6).
snarf returns the string currently in the snarf buffer. Writing this
file sets the contents of the snarf buffer. When rio is run re‐
cursively, the inner instance uses the snarf buffer of the par‐
ent, rather than managing its own.
text returns the full contents of the window. It may not be written.
wctl may be read or written. When read, it returns the location of
the window as four decimal integers formatted in the usual
12-character style: upper left x and y, lower right x and y.
Following these numbers are strings describing the window's
state: hidden or visible; current or notcurrent. A subsequent
read will block until the window changes size, location, or
state. When written to, wctl accepts messages to change the
size or placement of the associated window, and to create new
windows. The messages are in a command-line like format, with a
command name, possibly followed by options introduced by a minus
sign. The options must be separated by blanks, for example -dx
100 rather than -dx100.
The commands are resize (change the size and position of the
window), move (move the window), scroll (enable scrolling in the
window), noscroll (disable scrolling), set (change selected
properties of the window), top (move the window to the ‘top',
making it fully visible), bottom (move the window to the ‘bot‐
tom', perhaps partially or totally obscuring it), hide (hide the
window), unhide (restore a hidden window), current (make the
window the recipient of keyboard and mouse input), delete
(delete the window) and new (make a new window). The top and
bottom commands do not change whether the window is current or
not; the others always make the affected window current.
Neither top nor bottom has any options. The resize, move, and
new commands accept -minx n, -miny n, -maxx n, and -maxy n op‐
tions to set the position of the corresponding edge of the win‐
dow. They also accept an option -r minx miny maxx maxy to set
all four at once. The resize and new commands accept -dx n and
-dy n to set the width and height of the window. By default,
rio will choose a convenient geometry automatically.
Finally, the new command accepts an optional shell command and
argument string, given as plain strings after any standard op‐
tions, to run in the window instead of the default rc -i (see
rc(1)). The -pid pid option to new identifies the pid of the
process whose ‘note group' should receive interrupt and hangup
notes generated in the window. The initial working directory of
the new window may be set by a -cd directory option. The -hide
option causes the window to be created off-screen, in the hidden
state, while -scroll and -noscroll set the initial scrolling
state of the window; the default is that of the main program.
The set command accepts a set of parameters in the same style;
only -pid pid is implemented.
So programs outside name spaces controlled by rio may create
windows, wctl new messages may also be written to the named pipe
identified by $wctl.
wdir is a read/write text file containing rio's idea of the current
working directory of the process running in the window. It is
used to fill in the wdir field of plumb(6) messages rio gener‐
ates from the plumb menu item on button 2. The file is writable
so the program may update it; rio is otherwise unaware of
chdir(2) calls its clients make. In particular, rc(1) maintains
/dev/wdir in default rio(1) windows.
winid returns the unique and unchangeable ID for the window; it is a
string of digits.
window is the virtual version of /dev/screen. It contains the depth,
coordinates, and uncompressed raster image corresponding to the
associated window.
wsys is a directory containing a subdirectory for each window, named
by the unique ID for that window. Within each subdirectory are
entries corresponding to several of the special files associated
with that window: cons, consctl, label, mouse, etc.
EXAMPLES
Cause a window to be created in the upper left corner, and the word to
be printed there.
mount $wsys /tmp 'new -r 0 0 128 64 -pid '$pid
echo hi > /tmp/cons
Start sam(1) in a large horizontal window.
echo new -dx 800 -dy 200 -cd /sys/src/cmd sam > /dev/wctl
Print the screen image of window with id 123.
lp /dev/wsys/123/window
SOURCE
/sys/src/cmd/rio
SEE ALSO
rio(1), draw(3), mouse(3), cons(3), event(2), graphics(2).
RIO(4)