“Vi” Editor

vi filename

vi editor is a default editor of all Unix systems. It has several modes. Make sure that your terminal has correct settings, vt100 emulation works good if you are logged in using pc.

• i for insert mode.
  • I inserts text at the curson
  • A appends text at the end of the line.
  • a appends text after cursor.
  • O open a new line of text above the curson.
  • o open a new line of text below the curson.
• : for command mode.
  • <escape> to invoke command mode from insert mode.
  • :!sh to run unix commands.
  • x to delete a single character.
  • dd to delete an entire line
  • ndd to delete n number of lines.
  • d$ to delete from cursor to end of line.
  • yy to copy a line to buffer.
  • P to paste text from buffer.
  • nyy copy n number of lines to buffer.
  • :%s/stringA/stringb /g to replace stringA with stringB in whole file.
  • G to go to last line in file.
  • 1G to go to the first line in file.
  • w to move forward to next word.
  • b to move backwards to next word.
  • $ to move to the end of line.
  • J join a line with the one below it.
• /string to search string in file.
• n to search for next occurence of string.

Once you are done typing then to be in command mode where you can write/search/ you need to hit  :w filename to write, and in case you are done writing and want to exit :w! will write and exit.