tutes-dump/site-tutorials/misc

Rio is the Plan 9 window system.



To read more of this window, the up and down arrows

scroll the text up and down half screens.



To effectively use rio, you need at least a three

button mouse.  If you only have a two button mouse you

can emulate the middle button by holding down shift key

whilst pressing the right button.



Button 1, 2, and 3 are used to refer to the left,

middle, and right buttons respectively.



THE POP-UP MENU



Pressing and holding down button 3 on the desktop or

shell window will give you a menu with the following

options:



 * New - create a new window 

 * Resize - reshape a window 

 * Move - move a window without reshaping it 

 * Delete - close a window

 * Hide - hides a window from display (it will appear

   in this menu)

 * <label> - the label of a hidden window,

   selecting it unhides it



You select an item by releasing the button over the

menu item.  rio uses the same button that started an

action throughout that operation.  If you press another

button during the action the operation is aborted and

any intermediate changes are reversed.



The menu acts as a action verb selector which then

requires an object (i.e.  window) to be picked to

indicate which window the verb is to act on.  A further

mouse action may then be required.



EXAMPLES



After selecting New, the cursor will change into a

cross.  Using button 3 again, you should then drag out

a rectangle to indicate the size and location of the

new window.  When you release the button a new window

will be created.



New windows will contain the rc shell.  Invoking a rio

program from the shell will allow that program to take

over the window.  As there is no job control in the

shell (e.g.  &, fg, bg), you just create another window

if you want to run another program concurrently.



To Resize a window, you select Resize, then click

(remember using the same button that started the

action, i.e.  button 3) on the window you want to

resize.  The cursor will change to a cross-hair theat

will allow you to drag out the desired shape of the

window.



After selecting Move, click and keep the button

depressed over the window you want to move, then move

the mouse to move the red rectangle that represents the

new location you want.  Release the button to finish

the action.



Delete and Hide both operate by requiring you to click

on the window you wish to respectively Delete or Hide.



WINDOW CONTROL TIPS



Clicking on a window brings it to the front.



You can directly change the shape of a window by

clicking and dragging on the edge or corner of the

window border.  Button 1 or 2 will allow you to drag

the edge or corner to a new size, and Button 3 will

allow you to move the window.



The pop-up menu remembers the last command chosen, so

as a short cut you can just press and release button 3

without moving the mouse between pressing and releasing

to select the previous command again.



BASIC TEXT CONTROL



Unlike in other systems, the text cursor can only be

controlled by the mouse or the side-effects of certain

commands.



Clicking with button 1 will move the text insertion

point (indicated by an I-beam) to just before the

character closest to the mouse pointer.  Dragging

across a section of text will select that portion of

text.  It may be useful to know that the insertion

I-beam represents an empty selection (between two

characters).  In text editors, the current selection is

known as "dot".



In the shell window button 2 will invoke a pop-up menu.

Most of it's commands operate on dot.



 * cut - moves the contents of the dot to the clipboard

   if dot is non-empty 

 * paste - replaces dot with the contents of the clipboard

 * snarf - copies dot to the clipboard

 * plumb - sends dot (or text surrounding dot, if dot is

   empty)to the plumber.

 * send - completes the current input line with the dot,

   if it is non-empty, or the contents of the clipboard.

   If the dot is non-empty it does a snarf at the same time.

 * scroll - toggles the automatic scrolling of the window

   on output.



Double-clicking will allow you to automatically select

a section of text surrounding that point.  The

selection is made by an analysis of appropriate

delimeters.  A whole line is selected by

double-clicking at either end of the line.  A quoted or

bracketed selection is made by double-clicking just

inside of the quote or bracket.



SCROLLING



The arrow keys will let you scroll up or down by half a

page at a time.



Clicking button 1 on the scrollbar scrolls up by half a

page.  Button 3 scrolls down by half a page.  Button 2

jumps to position in the document relative to the

position on the scrollbar clicked.  Holding a button on

the scrollbar will have the effect of invoking the

clicking action continuously.



The white elevator box on the scrollbar is sized

proportionally to the proportion of the document that

is currently visible.



Scrolling does not affect the text cursor.



RIO AND THE RC SHELL WINDOW



Rc is a command interpreter for Plan 9 that provides

similar facilities to UNIX's Bourne shell.  See the

additional references at the end of this document for

information specifically about rc.



Rio provides some additional features that enhance the

interface to programs that use the text console.  The

rc shell command interpreter is one such program.



Rc commands are typed after the prompt on the last line

of the text buffer.  The commands are sent to rc only

after each newline so line editing may be performed if

desired.  You can move the cursor and edit the previous

lines of commands and program output but none of this

will be interpreted by rc shell.



The interpretation of commands is supressed altogether

when ESC is pressed to put the window in hold mode.

The window border and text will change to dark blue to

indicate the hold mode is active.  In this mode you can

type multiple lines of commands and edit them.

Pressing ESC again will release the hold and send the

lines of text to the rc command interpreter.



The DEL key sends an 'interrupt' note to all processes

in the window's process group.  The usual intent is to

terminate the execution of the current command.  It is

also a convenient short cut for ensuring you have a

fresh command prompt.



FURTHER INFORMATION



For further information, try the rio(1) manual page.

Type "man rio" or click on rio(1) in either of these

sentences and select plumb from the button 2 menu.