Vi has two modes, command and insert (really, three if you count replace mode). Command mode is used to navigate, search, and issue other commands. Insert mode is used to enter text.
While in command mode (case sensitive)
move the cursor with arrow keys; if there aren't any arrow keys, use j,k,h,l
Type "vi file.txt" at command prompt
Move cursor to where new text will be added
Type "i" to change to insert mode
Type new text
Type ESC to go back to command mode
type ":wq" and ENTER to write the file and quit
move the cursor with arrow keys; if there aren't any arrow keys, use j,k,h,l
i - change to insert mode (before cursor)
a - change to insert mode (after cursor)
A - change to insert mode (at end of line)
r - replace one character
R - overwrite text
x - delete one character
dd - delete one line
yy - yank line (copy)
p - paste deleted or yanked text after cursor
P - paste deleted or yanked text before cursor
G - go to end of the file
1G - go to top of the file
J - merge next line with this one
/ - search, follow / with text to find
:wq - write file and quit
:q! - quit without saving
%s/old/new/g - substitute; replace "old" with "new" on all lines
:g/pattern/d - delete all lines that match the pattern
a - change to insert mode (after cursor)
A - change to insert mode (at end of line)
r - replace one character
R - overwrite text
x - delete one character
dd - delete one line
yy - yank line (copy)
p - paste deleted or yanked text after cursor
P - paste deleted or yanked text before cursor
G - go to end of the file
1G - go to top of the file
J - merge next line with this one
/ - search, follow / with text to find
:wq - write file and quit
:q! - quit without saving
%s/old/new/g - substitute; replace "old" with "new" on all lines
:g/pattern/d - delete all lines that match the pattern
While in insert mode
ESC - change to command mode
ESC - change to command mode
any text typed is entered at the cursor
Typical vi session
Type "vi file.txt" at command prompt
Move cursor to where new text will be added
Type "i" to change to insert mode
Type new text
Type ESC to go back to command mode
type ":wq" and ENTER to write the file and quit
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