term% cat index.txt RIO(1) General Commands Manual RIO(1)
NAME
rio, label, window, wloc - window system
SYNOPSIS
rio [ -i 'cmd' ] [ -k 'kbdcmd' ] [ -s ] [ -f font ]
label name
window [ -m ] [ -r minx miny maxx maxy ] [ -dx n ] [ -dy n ] [ -minx n
] [ -miny n ] [ -maxx n ] [ -maxy n ] [ -cd dir ] [ -hide ] [ -scroll ]
[ -noscroll ] [ cmd arg ... ]
wloc
DESCRIPTION
Rio manages asynchronous layers of text, or windows, on a raster dis‐
play. It also serves a variety of files for communicating with and
controlling windows; these are discussed in section rio(4).
Commands
The rio command starts a new instance of the window system. Its -i op‐
tion names a startup script, which typically contains several window
commands generated by wloc. The -k option causes rio to run the com‐
mand kbdcmd at startup and allow it to provide characters as keyboard
input; the keyboard program described in bitsyload(1) is the usual
choice.
The -s option initializes windows so that text scrolls; the default is
not to scroll. The font argument names a font used to display text,
both in rio's menus and as a default for any programs running in its
windows; it also establishes the environment variable $font. If -f is
not given, rio uses the imported value of $font if set; otherwise it
imports the default font from the underlying graphics server, usually
the terminal's operating system.
The label command changes a window's identifying name.
The window command creates a window. By default, it creates a shell
window and sizes and places it automatically. The geometry arguments
control the size (dx, dy) and placement (minx, miny, maxx, maxy); the
units are pixels with the upper left corner of the screen at (0, 0).
The hide option causes the window to be created off-screen. The scroll
and noscroll options set the scroll mode. The cd option sets the work‐
ing directory. The optional command and arguments define which program
to run in the window.
By default, window uses /dev/wctl (see rio(4)) to create the window and
run the command. Therefore, the window and command will be created by
rio and run in a new file name space, just as if the window had been
created using the interactive menu. However, the -m option uses the
file server properties of rio to mount (see bind(1)) the new window's
name space within the name space of the program calling window. This
means, for example, that running window in a CPU window will create an‐
other window whose command runs on the terminal, where rio is running;
while window -m will create another window whose command runs on the
CPU server.
The wloc command prints the coordinates and label of each window in its
instance of rio and is used to construct arguments for window.
Window control
Each window behaves as a separate terminal with at least one process
associated with it. When a window is created, a new process (usually a
shell; see rc(1)) is established and bound to the window as a new
process group. Initially, each window acts as a simple terminal that
displays character text; the standard input and output of its processes
are attached to /dev/cons. Other special files, accessible to the
processes running in a window, may be used to make the window a more
general display. Some of these are mentioned here; the complete set is
discussed in rio(4).
One window is current, and is indicated with a dark border and text;
characters typed on the keyboard are available in the /dev/cons file of
the process in the current window. Characters written on /dev/cons ap‐
pear asynchronously in the associated window whether or not the window
is current.
Windows are created, deleted and rearranged using the mouse. Clicking
(pressing and releasing) mouse button 1 in a non-current window makes
that window current and brings it in front of any windows that happen
to be overlapping it. When the mouse cursor points to the background
area or is in a window that has not claimed the mouse for its own use,
pressing mouse button 3 activates a menu of window operations provided
by rio. Releasing button 3 then selects an operation. At this point,
a gunsight or cross cursor indicates that an operation is pending. The
button 3 menu operations are:
New Create a window. Press button 3 where one corner of the new
rectangle should appear (cross cursor), and move the mouse,
while holding down button 3, to the diagonally opposite corner.
Releasing button 3 creates the window, and makes it current.
Very small windows may not be created.
Resize Change the size and location of a window. First click button 3
in the window to be changed (gunsight cursor). Then sweep out a
window as for the New operation. The window is made current.
Move Move a window to another location. After pressing and holding
button 3 over the window to be moved (gunsight cursor), indicate
the new position by dragging the rectangle to the new location.
The window is made current. Windows may be moved partially off-
screen.
Delete Delete a window. Click in the window to be deleted (gunsight
cursor). Deleting a window causes a note to be sent to all
processes in the window's process group (see notify(2)).
Hide Hide a window. Click in the window to be hidden (gunsight cur‐
sor); it will be moved off-screen. Each hidden window is given
a menu entry in the button 3 menu according to the value of the
file /dev/label, which rio maintains (see rio(4)).
label Restore a hidden window.
Windows may also be arranged by dragging their borders. Pressing but‐
ton 1 or 2 over a window's border allows one to move the corresponding
edge or corner, while button 3 moves the whole window.
Text windows
Characters typed on the keyboard or written to /dev/cons collect in the
window to form a long, continuous document.
There is always some selected text, a contiguous string marked on the
screen by reversing its color. If the selected text is a null string,
it is indicated by a hairline cursor between two characters. The se‐
lected text may be edited by mousing and typing. Text is selected by
pointing and clicking button 1 to make a null-string selection, or by
pointing, then sweeping with button 1 pressed. Text may also be se‐
lected by double-clicking: just inside a matched delimiter-pair with
one of {[(<«‘'" on the left and }])>»‘'" on the right, it selects all
text within the pair; at the beginning or end of a line, it selects the
line; within or at the edge of an alphanumeric word, it selects the
word.
Characters typed on the keyboard replace the selected text; if this
text is not empty, it is placed in a snarf buffer common to all windows
but distinct from that of sam(1).
Programs access the text in the window at a single point maintained au‐
tomatically by rio. The output point is the location in the text where
the next character written by a program to /dev/cons will appear; af‐
terwards, the output point is the null string beyond the new character.
The output point is also the location in the text of the next character
that will be read (directly from the text in the window, not from an
intervening buffer) by a program from /dev/cons. When such a read will
occur is, however, under control of rio and the user.
In general there is text in the window after the output point, usually
placed there by typing but occasionally by the editing operations de‐
scribed below. A pending read of /dev/cons will block until the text
after the output point contains a newline, whereupon the read may ac‐
quire the text, up to and including the newline. After the read, as
described above, the output point will be at the beginning of the next
line of text. In normal circumstances, therefore, typed text is deliv‐
ered to programs a line at a time. Changes made by typing or editing
before the text is read will not be seen by the program reading it. If
the program in the window does not read the terminal, for example if it
is a long-running computation, there may accumulate multiple lines of
text after the output point; changes made to all this text will be seen
when the text is eventually read. This means, for example, that one
may edit out newlines in unread text to forestall the associated text
being read when the program finishes computing. This behavior is very
different from most systems.
Even when there are newlines in the output text, rio will not honor
reads if the window is in hold mode, which is indicated by a white cur‐
sor and blue text and border. The ESC character toggles hold mode.
Some programs, such as mail(1), automatically turn on hold mode to sim‐
plify the editing of multi-line text; type ESC when done to allow mail
to read the text.
An EOT character (control-D) behaves exactly like newline except that
it is not delivered to a program when read. Thus on an empty line an
EOT serves to deliver an end-of-file indication: the read will return
zero characters. Like newlines, unread EOTs may be successfully edited
out of the text. The BS character (control-H) erases the character be‐
fore the selected text. The ETB character (control-W) erases any non‐
alphanumeric characters, then the alphanumeric word just before the se‐
lected text. ‘Alphanumeric' here means non-blanks and non-punctuation.
The NAK character (control-U) erases the text after the output point,
and not yet read by a program, but not more than one line. All these
characters are typed on the keyboard and hence replace the selected
text; for example, typing a BS with a word selected places the word in
the snarf buffer, removes it from the screen, and erases the character
before the word.
An ACK character (control-F) or Insert character triggers file name
completion for the preceding string (see complete(2)).
Typing a left or right arrow moves the cursor one character in that di‐
rection. Typing an SOH character (control-A) moves the cursor to the
beginning of the current line; an ENQ character (control-E) moves to
the end.
Text may be moved vertically within the window. A scroll bar on the
left of the window shows in its clear portion what fragment of the to‐
tal output text is visible on the screen, and in its gray part what is
above or below view; it measures characters, not lines. Mousing inside
the scroll bar moves text: clicking button 1 with the mouse pointing
inside the scroll bar brings the line at the top of the window to the
cursor's vertical location; button 3 takes the line at the cursor to
the top of the window; button 2, treating the scroll bar as a ruler,
jumps to the indicated portion of the stored text. Holding a button
pressed in the scroll bar will cause the text to scroll continuously
until the button is released. Also, a page down or down-arrow scrolls
forward half a window, and page up or up-arrow scrolls back. Typing
the home key scrolls to the top of the window; typing the end key
scrolls to the bottom.
The DEL character sends an note to all processes in the window's
process group. Unlike the other characters, the DEL, VIEW, and up- and
down-arrow keys do not affect the selected text. The left (right) ar‐
row key moves the selection to one character before (after) the current
selection.
Normally, written output to a window blocks when the text reaches the
end of the screen; a button 2 menu item toggles scrolling.
Other editing operations are selected from a menu on button 2. The cut
operation deletes the selected text from the screen and puts it in the
snarf buffer; snarf copies the selected text to the buffer without
deleting it; paste replaces the selected text with the contents of the
buffer; and send copies the snarf buffer to just after the output
point, adding a final newline if missing. Paste will sometimes and
send will always place text after the output point; the text so placed
will behave exactly as described above. Therefore when pasting text
containing newlines after the output point, it may be prudent to turn
on hold mode first.
The plumb menu item sends the contents of the selection (not the snarf
buffer) to the plumber(4). If the selection is empty, it sends the
white-space-delimited text containing the selection (typing cursor). A
typical use of this feature is to tell the editor to find the source of
an error by plumbing the file and line information in a compiler's di‐
agnostic.
Raw text windows
Opening or manipulating certain files served by rio suppresses some of
the services supplied to ordinary text windows. While the file
/dev/mouse is open, any mouse operations are the responsibility of an‐
other program running in the window. Thus, rio refrains from maintain‐
ing the scroll bar, supplying text editing or menus, interpreting the
VIEW key as a request to scroll, and also turns scrolling on.
The file /dev/consctl controls interpretation of keyboard input. In
particular, a raw mode may be set: in a raw-input window, no typed key‐
board characters are special, they are not echoed to the screen, and
all are passed to a program immediately upon reading, instead of being
gathered into lines.
Graphics windows
A program that holds /dev/mouse and /dev/consctl open after putting the
console in raw mode has complete control of the window: it interprets
all mouse events, gets all keyboard characters, and determines what ap‐
pears on the screen.
FILES
/lib/font/bit/*
font directories
/mnt/wsys
Files served by rio (also unioned in /dev in a window's name
space, before the terminal's real /dev files)
/srv/rio.user.pid
Server end of rio.
/srv/riowctl.user.pid
Named pipe for wctl messages.
SOURCE
/sys/src/cmd/rio
/rc/bin/label
/rc/bin/window
/rc/bin/wloc
SEE ALSO
rio(4), rc(1), cpu(1), sam(1), mail(1), proof(1), graphics(2),
frame(2), window(2), notify(2), cons(3), draw(3), mouse(3), keyboard(6)
BUGS
The standard input of window is redirected to the newly created window,
so there is no way to pipe the output of a program to the standard in‐
put of the new window. In some cases, plumb(1) can be used to work
around this limitation.
RIO(1)