vi - invoke a screen-oriented display editor

Description

The vi command offers a powerful set of text editing operations based on

a set of mnemonic commands. Most commands are single keystrokes that

perform simple editing functions. vi displays a full screen ``window''

into the file you are editing. The contents of this window can be

changed quickly and easily within vi. While editing, visual fedback is

provided (the name vi itself is short for ``visual'').

Special keys

There are several special keys in vi. The following keys are used to

edit, delimit, or abort commands and command lines.

<Esc> Used to return to vi command mode or to cancel partialy

formed commands.

<Return> Used to start a newline when in insert mode.

/ Used to specify a string to be searched for. The slash

apears on the status line as a prompt for a search string.

The question mark (?) works exactly like the slash key,

except that it is used to search backward in a file instead

of forward.

: The colon is a prompt for a command. You can then type

in any command, followed by an <Esc> or <Return>, and the

given command is executed.

Starting and exiting vi

To enter vi

v - Special Entrance into vi from viewing an MDS Printfile.

Enter a lower case v any time after pressing the View Selection

from the MDS View/Print Screen.

vi file Type this in at the Unix command prompt (# or $)

to Edit named file

There are several ways to exit the editor:

:ZZ The editing buffer is writen to the file only if any changes were

made.

:q! Cancels an editing sesion. The exclamation mark (!) tells vi to

quit unconditionaly. In this case, the editing buffer is not writ-

ten out.

vi commands

Cursor Movement

---------------

The cursor movement keys alow you to move your cursor around in a file.

forward space - right arrow or space bar

backkspace - left arrow or back-space key

next line - <<return>> and down arrow

previous line - up arrow

end of line - $

goto line - :[LineNumber] and return key

To go to the last line in file use <Ctrl>G

To find the line number of the current line, use <Ctrl>g.

SCREEN COMMANDS

---------------

The screen commands move the cursor and are useful in paging or scrolling

through a file. These commands are described below:

scroll- <<ctrl>>u and <<ctrl>>d

Syntax: [size]<Ctrl>u

[size]<Ctrl>d

Function: Scrolls the screen up a half window (<Ctrl>u) or down a half

window (<Ctrl>d). If size is given, the scroll is size number

of lines. This value is remembered for all later scrolling

commands.

page - <<ctrl>>f and <<ctrl>>b

Syntax: <Ctrl>f

<Ctrl>b

Function: Pages screen forward and backward. Two lines of continuity are

kept betwen pages if posible. A preceding count gives the

number of pages to move forward or backward.

status - <<ctrl>>g

Syntax: bell

<Ctrl>g

Function: Displays vi status on status line. This gives you the name of

the file you are editing, whether it has been modified, the

current line number, the number of lines in the file, and the

percentage of the file (in lines) that precedes the cursor.

Text Insertion

--------------

The text insertion commands always place you in insert mode. Exit from

insert mode is always done by pressing <Esc>. The following insertion

commands are pure insertion commands; no text is deleted when you use

them. This difers from the text modification commands, change, replace,

and substitute, which delete and then insert text in one operation.

insert - i

Syntax: i[text]<Esc>

Function: Insert text in editing buffer. The lowercase i command places

you in insert mode. text is inserted before the character

beneath the cursor.

Exit insert mode by typing the <Esc> key.

append - a

Syntax: a[text]<Esc>

Function: Appends text to the editing buffer.

This is the only way to add text to the end of a line.

command begins appending text after the cursor.

open new line - o and O

Syntax: o[text]<Esc>

O[text]<Esc>

Function: Opens a new line and inserts text. The lowercase o command

opens a new line below the current line; uppercase O opens a

new line above the current line. After the new line has ben

opened, both these commands work like the i command.

Text Deletion

-------------

Many of the text deletion commands use the ``d'' key as an operator.

This operator deletes text objects delimited by the cursor and a cursor

movement command. Deleted text is always saved in a buffer. The delete

commands are described below:

delete character - x

Syntax: x

Function: Deletes a character.

This is a quick and easy way to delete a few characters.

delete - dd and D

Function:

The dd command deletes whole lines. The uppercase D command

deletes from and including the cursor to the end of the curent

line.

Text Modification

-----------------

The text modification commands all involve the replacement of text with

other text. This means that some text will necesarily be deleted. Al

text modification commands can be ``undone'' with the u command:

undo - u and U

Syntax: u

U

Function: Undoes the last insert or delete command. The lowercase u com-

mand undoes the last insert or delete command. This means that

after an insert, u deletes text; and after a delete, u inserts

text. For the purposes of undo, all text modification commands

are considered insertions.

The uppercase U command restores the current line to its state

before it was edited, no mater how many times the current line

has been edited since you moved to it.

repeat . This a period.

Syntax: .

Function: Repeats the last insert or delete command.

replace - r and R

Syntax: rchar

Rtext <Esc>

Function: Overstrikes character or line with char or text, respectively.

Use r to overstrike a single character and R to overstrike a

whole line.

Join lines - J

Syntax: J

Function: Joins the current line with the following line.

Searching

---------

The search commands search either forward or backward in the editing

buffer for text that matches a given regular expression.

search - / and ?

Syntax: /[pattern]<Return>

?[pattern]<Return>

Function: Searches forward (/) or backward (?) for pattern.

If no pattern is given, then the last pattern

searched for is used.

next string - n and N

Syntax: n

N

Function: Repeats the last search command. The n command repeats the

search in the same direction as the last search command. The N

command repeats the search in the oposite direction of the

last search command.