The most common editor for a UNIX machine like bgunix is the vi editor. To use vi to create or edit a file, use this command:
vi filename
There are two different operating modes:
Command mode This is the normal and initial startup state. You can enter commands but no text.
Insert mode In Insert mode you can type text into the file, but you cannot enter any commands. To enter a command you must first return to Command mode by pressing the ESC key.
Commands to change from Command mode to Text mode
i
inserts text at cursor position
I
inserts text at the beginning of the current line
a
appends text after the current character
A
appends text at the end of the current line
o
adds a blank line below the current line
O (letter O)
adds a blank line above the current line
Commands to save the file and/or quit vi
ZZ
writes the file to disk and quits
:wq
writes the file to disk and quits
:q
quits the session if nothing changed in document
:q!
quits the session without saving any changes to the file
:w filename
writes the buffer contents to a new filename without exiting to shell; will not write to an existing file
:w! filename
writes the buffer contents to an existing filename, overwrites contents of existing file
Commands to move around in your document
cursor (arrow) keys
moves up, down, left, or right one position
$
moves to end of line
0 (zero)
moves to beginning of line
H
moves to the top of the screen
M
moves to the middle of the screen
L
moves to the bottom of the screen
G
moves to the last line of the file
nG
moves to line n of the file (e.g. 7G moves to line seven)
Ctrl-F
moves to the next page (hold down Ctrl, press F)
Ctrl-B
moves to the previous page (hold down Ctrl, press B)
Commands to delete or replace parts of the document
x
deletes the character under the cursor
X
deletes the character before the cursor
D
deletes from the character under the cursor to the end of the line
dd
deletes the current line. (The line deleted is put into the General-purpose Buffer)
r
replaces the character under the cursor and stays in Command mode
R
replaces the character under the cursor and remains in overwrite mode (following text will be overwritten)
The x, X, and dd commands can be preceded by an integer to delete multiple characters or lines (e.g. 12x or 12dd).
Commands to move lines within the document
dd
deletes the current line, putting it into the General-Purpose Buffer
ndd
deletes n lines starting with the current line, putting them into the General-Purpose Buffer
yy
copies (yanks) the current line to the General-Purpose Buffer
nyy
copies (yanks) n lines starting with the current line, putting them into the General Purpose Buffer
p
inserts the lines from the General-Purpose Buffer just after the current line
P
inserts the lines from the General-Purpose Buffer just before the current line
Commands to search and replace a string
/searchstring
searches forward for searchstring
?searchstring
searches backward for searchstring
n
repeats the last search
N
repeats the last search in the opposite direction
:%s/searchstring/replacestring
replaces the first searchstring occurrence with replacestring
:%s/searchstring/replacestring/g
replaces all searchstring occurrences with replacestring
BGSU B.S. in Computer Science is accredited by the Computing Accreditation Commission of ABET, www.abet.org, under the commission’s General Criteria and Program Criteria for Computer Science.
BGSU B.S. in Software Engineering is accredited by the Engineering Accreditation Commission of ABET, www.abet.org, under the commission’s General Criteria and Program Criteria for Software Engineering.
