Usefull vi commands

Some useful commands to work with vi

character explanation
i insert
9yl copy nine characters from cursor position, e.g 192.168.1.0 192.168.1 will be copied
p paste what you have copied
x delete character
:wq write and quit (save and close)
/search_string find search_string
n go to next occurrence of search_string
N go to previous occurrence of search_string
dd delete line
10dd delete next 10 lines
yy copy line
10yy copy next 10 lines
r replace current character at cursor
R replace current word at cursor