Shell command-----VI

Basic operation of VI

A) Enter VI after the system hint sign VI and file name, go to the VI Full screen editing screen: $ VI file
However, it is important to note that after you enter VI, you are in command mode and you want to switch to insert mode to enter text.

b) switch to insert mode to edit the file
Press the letter "i" under Command mode to enter "Insert Mode", and you can start typing the text again at this point.

c) Toggle of Insert
You are currently in "Insert Mode", you can only enter text, if you find the wrong word! To move back with the cursor key, delete the word, then click the "esc" key to go to "command mode" and then delete the text.

d) Exit VI and save the file
Under Command mode, click the ":" colon key to enter "last line mode", for example:
: w filename (enter "w filename" to save the article with the filename you specified)
: Wq (input "wq", save and Exit VI)
: q! (Enter q!, do not save the mandatory exit VI)

command-line mode function keys

1). Insert mode
Press "i" switch into insert mode "insert mode", press "I" into the insertion mode is the beginning of the cursor from the current position to enter the file;
After pressing "a" into insert mode, the text is entered from the next position at the current cursor position;
When you press "o" to enter insert mode, you insert a new line and enter text from the beginning of the beginning.

2). Switch from insert mode to command line mode
Press the "esc" key.

3). Move the cursor
VI can be directly on the keyboard with the cursor to move up and down, but the normal VI is the lowercase English letter "h", "j", "k", "l", respectively, control the cursor left, bottom, upper, and right one grid.
Press "ctrl"+"b": The screen moves one page to the back.
Press "ctrl"+"f": The screen moves one page to the front.
Press "ctrl"+"u": The screen moves the half page toward the back.
Press "ctrl"+"d": The screen moves the half page toward the front.
"0" by number: Moves to the beginning of the article.
Press "g": Move to the end of the article.
Press "$": Moves to the end of the line where the cursor is located.
Press "^": Moves to the beginning of the line where the cursor is located
Press "w": Cursor jumps to the beginning of the next word
Press "e": Cursor jumps to the end of the next word
Press "b": Cursor back to the beginning of the last word
Press #l: The cursor moves to the first # position of the line, such as: 5l,56l.

4). Delete text
"x": Each time you press the cursor, delete the "after" character at the position where the pointer is located.
#x: For example, "6x" represents the "after" 6 characters of the location where the cursor was deleted.
"x": Uppercase X, each time it is pressed, deletes the "front" character at the location of the cursor.
"#X": for example, "20x" represents the "front" 20 characters of the location where the cursor was deleted.
"dd": Delete the line where the cursor is located.
"#dd": Deletes the # line starting at the line where the cursor is located

5). Copy
"yw": Copies the characters from the cursor to the end of the word into the buffer.
"#yw": Copy # words to Buffer
"yy": Copy cursor line to buffer.
"#yy": for example, "6yy" represents a copy of 6 lines of text from the line where the cursor is located.
"p": Paste the characters in the buffer to the cursor location. Note: All copy commands related to "Y" must be mated with "P" to complete the copy and paste function.

6). Find

/pattern: Search from the beginning of the cursor at the end of the file Pattern
? pattern: Searches for pattern from the beginning of the cursor to the top of the file

7). Replace

　　: 1, $s/oldstr/newstr/g in full-text range with NEWSTR replacement OLDSTR

: n,ms/oldstr/newstr/g replace oldstr with Newstr on line N to M

Shell command-----VI