term% ls -F
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RIO(4)                     Kernel Interfaces Manual                     RIO(4)

       rio - window system files

       rio [ -i 'cmd' ] [ -s ] [ -f font ]

       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‐

       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)).

              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.

       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


       rio(1), draw(3), mouse(3), cons(3), event(2), graphics(2).